DaveT Posted September 21, 2006 Share Posted September 21, 2006 otherwise, some of us still dont understand. I have a spare one here, pulled the cover off. A piece of plastic has 4 brass tabs molded into it. the 3 nichrome reistors are wired in a string from 1 tab, to the next, next.... 2 tabs are at the extreme ends (highest & lowest speeds). 2 tabs are along the string. Each of them has 2 resistor ends connected to the tab. My original post was refering to the rsistors themselves breaking. Not likely to loose only 1 speed (except the lowest) by 1 resistor failing. And also, from the perspective of repairing the block, or wire. A wire that goes from the block to the connector could cause only 1 middle speed to fail. Probably best to remove it and take a look. You could test it with an ohm meter without removing the block, just pull the 4 pin plug. Expect the resistances to be pretty low. Link to comment Share on other sites More sharing options...
daeron Posted September 21, 2006 Share Posted September 21, 2006 allright, i guess in retrospect it was pretty obvious how only one missing speed could be from a bad resistor block... i hadnt thought of the possibility of a "bad block" without assuming that meant "burnt resistor" with a complete failure of this resistor block, high speed still works fine right?? thats the important part, those other speeds are just fancypants options anyhow. (no, i dont live in a region with oppressive heat and humidity, honest) Link to comment Share on other sites More sharing options...
edrach Posted September 21, 2006 Share Posted September 21, 2006 with a complete failure of this resistor block, high speed still works fine right?? Right, complete open circuit puts full voltage to the blower. Link to comment Share on other sites More sharing options...
rallyruss Posted September 21, 2006 Share Posted September 21, 2006 Beataru I thought I told you about that? I already diagnosed it and yes it needs a resistor. the low speed coil is burnt out. yeah I made a feeble attempt to solder it. really pointless. dont bother. order a new one. Link to comment Share on other sites More sharing options...
bgd73 Posted September 21, 2006 Share Posted September 21, 2006 I have got two bad 1 and 2. Common place for the fan switch, my loyale is a roaster. what were the numbers of resistence? would voltage regulator work? a hak at it? if original is broken all the time, there must be something stronger...Is the photo below the part referred to? A critter mad an adobe mud house out of it: Link to comment Share on other sites More sharing options...
bgd73 Posted September 21, 2006 Share Posted September 21, 2006 This fix worked for me. By the time I was done breaking the brittle stuff away, it left nearly a straight shot between way points. I put in yet another resistor to take some of the heat. Just like almost not quite like new! Of course I wouldn't recommend, but it did stay cool enough to hold low temp solder, with extra resistor, taking my concern away about no coils to cool like the one on left in photo. The resistor is for a Zalman 12volt pc fan- 56ohm, tricking it into a 5volt mode. I had a hunch it would help this scenario of burning the resistor coils in the car.Time will tell, I just fixed it and let it run on one and two, and even put my finger near or on what was left to see if it would hold, and it did.With my engine cooler as a bonus, and the resistors getting direct air installed, I personally am keeping it as a fix. Like a 10ohm radio shack resistor in the ecu! Link to comment Share on other sites More sharing options...
DaveT Posted September 22, 2006 Share Posted September 22, 2006 what were the numbers of resistence? would voltage regulator work? a hak at it? if original is broken all the time, there must be something stronger... The biggest one is 0.5 ohm. The second is 0.68 ohm. On the block I have handy, the third is broken. The one I fixed, I just found a similar length of similar sized nichrome. Probably from an EA81 blower, because I had several of them before moving to the EA82 cars. The mud condo is probably a mud wasp nest. A linear voltage regulator would need a big heat sink. The nichrome resistors are all black and crusty because they run hot. That means a lot of power is dissapated in them. A linear regulator would need to dissapte the same amount of power, but has to be kept much cooler. I did make an infinitly variable switched mode speed controller for one of these blowers I used for another application where high efficiency at lower speeds mattered. Link to comment Share on other sites More sharing options...
daeron Posted September 22, 2006 Share Posted September 22, 2006 I am a self-proclaimed "tweak freak" who has acquired a great working knowledge of electrical switchery, but the concepts involved in making such an infinitely veriable speed selection are beyond me. this entire thread has fascinated me because its all stuff ive known about, and known how simple it all was, but didnt know how to build it myself. does anyone have any resources that i can use to learn more along these lines? one project thats on my "to-do" list is engineering variable speed intermittent wipers onto my Zcar.. its gotta be a simple matter of replacing the single speed intermittent relay with a variable resistor-type relay circuit.... but thats as far as i can get. I know i can LEARN how to do that, but i dont know where since im not in college anyone got any helpful links, or places i could go? i'll probly try wikipedia, but i dunno what i would look up. maybe in my Brittanica.... Link to comment Share on other sites More sharing options...
bgd73 Posted September 22, 2006 Share Posted September 22, 2006 I did make an infinitly variable switched mode speed controller for one of these blowers I used for another application where high efficiency at lower speeds mattered. Wo! Theres an idea! I don't think a Cadillac would even have that one. If to do so, the resistor block wiring has everything to do with it? or is the heater engine set for simple changes, Hi-Lo, and a setting inbetween? How rheostatical can it be? I recently took apart a house fan with 3 speeds, and the wiring to change speed was built right into the engine. Finding the four wires for heater motor, I assumed the aforementioned non-rheostat ability. Link to comment Share on other sites More sharing options...
msteel Posted September 22, 2006 Share Posted September 22, 2006 A switching speed regulator would be spiffy, and I've thought about doing it to mine as I've lost 2 speeds and Subarus are rare in junkyards in my area. It could be made fairly easily with a 555 timer circuit (or maybe a PIC buit you'd need a programmer) and a suitable transistor. The biggest trouble is incorporating the standard speed switch and "off" switch in the mode selector. You'd likely need to add a power supply wire and maybe a ground to run the electronics. Link to comment Share on other sites More sharing options...
bgd73 Posted September 22, 2006 Share Posted September 22, 2006 if the engine is dynamical, this should be easy... here is an interesting site mentionoing some of the ways to variate what the goal is. http://www.kpsec.freeuk.com/components/vres.htm The question to me is how dynamical are the preset changes in the heater engine. 1 would have to variate to 2, which will variate,and on to maximum, all rheostatically- if to use original blower. I remember messing with a "101 electronics kit" when I was 10, that had the variator type stuff for a lights brighness, it was quite simple. Maybe just hook it all up to the blower motors "4" or high position and see how far it variates without the other wires. Although, using all of it would be good for engine? That same site mentioned gives a good rundown on typical circuit parts/electronics. What Subaru put together in the resistor block is quite cheap. There are several combinations to get what they want, but a sloppy means to do so. The resistor I put in really does take the edge off of another failure,functioning either direction, and no coils to trap stuff is a bonus.With what I just read, there is a means to get that with a small circuit, seperating the sloppiness a bit more. subaru must have figured the engine could take such changes, without all that much precision. Maybe to overlap it as a buffer of tolerance. Maybe it is smarter than I can figure, and I am babbling out of boredom.. Link to comment Share on other sites More sharing options...
daeron Posted September 23, 2006 Share Posted September 23, 2006 if the engine is dynamical, this should be easy... here is an interesting site mentionoing some of the ways to variate what the goal is. http://www.kpsec.freeuk.com/components/vres.htm The question to me is how dynamical are the preset changes in the heater engine. 1 would have to variate to 2, which will variate,and on to maximum, all rheostatically- if to use original blower. I remember messing with a "101 electronics kit" when I was 10, that had the variator type stuff for a lights brighness, it was quite simple. Maybe just hook it all up to the blower motors "4" or high position and see how far it variates without the other wires. Although, using all of it would be good for engine? That same site mentioned gives a good rundown on typical circuit parts/electronics. What Subaru put together in the resistor block is quite cheap. There are several combinations to get what they want, but a sloppy means to do so. The resistor I put in really does take the edge off of another failure,functioning either direction, and no coils to trap stuff is a bonus.With what I just read, there is a means to get that with a small circuit, seperating the sloppiness a bit more. subaru must have figured the engine could take such changes, without all that much precision. Maybe to overlap it as a buffer of tolerance. Maybe it is smarter than I can figure, and I am babbling out of boredom.. allright now maybe this is my elementary knowledge speaking here, but wouldnt the design of the resistor block indicate that the blower motor is easily infinitely variable, depending on input voltage? because the resistor block simply adds one, two, or three wraps of resistor wire into the circuit between the switch and motor.. the switch would feed power to terminal 1,2,3, or 4.. T4 would be straight thru, no resistance, high blower.. and each lower terminal would add one wrap of resistor wire into the circuit. it just seemed to me like this resistor block is a dummy, four step way of adding a resistance value into the power feed circuit and could be replaced by a simple rheostatic controller.... but again, i can talk a little smarter than i can really think about all this stuff, AND i havent seen any of the components in question yet, since i havent opened up my car. am i wrong in my conception of things? Link to comment Share on other sites More sharing options...
bgd73 Posted September 23, 2006 Share Posted September 23, 2006 allright now maybe this is my elementary knowledge speaking here, but wouldnt the design of the resistor block indicate that the blower motor is easily infinitely variable, depending on input voltage? because the resistor block simply adds one, two, or three wraps of resistor wire into the circuit between the switch and motor.. the switch would feed power to terminal 1,2,3, or 4.. T4 would be straight thru, no resistance, high blower.. and each lower terminal would add one wrap of resistor wire into the circuit. it just seemed to me like this resistor block is a dummy, four step way of adding a resistance value into the power feed circuit and could be replaced by a simple rheostatic controller.... but again, i can talk a little smarter than i can really think about all this stuff, AND i havent seen any of the components in question yet, since i havent opened up my car. am i wrong in my conception of things? I bet it treats the air with heat too, before thermostat opens, etc. It is no doubt a Subaru thing that could be made differently. Ironically after making a diagram of the fire path of an EA82, the resistor block is the lines of the map when you follow the combinations . I wondered if the engineers were having a giddy good time makin that retarded resistor. The engines are no doubt wired within as well as out. There are 2 pairs for this reason. To go dynamically inbetween them, without forgetting a pair would be the best bet.:-\ I am content with the 1-4, but I do remeber an eldorado Cadillac as a kid with an led for temperature and many settings by pressing up or down for better dynamics. After 9 years solid with same old school sube setup, I don't need the gadgets but for something unique. I won't be tinkering anytime soon, other than conversation. Link to comment Share on other sites More sharing options...
DaveT Posted September 23, 2006 Share Posted September 23, 2006 Some more electronics / heater blower details: The electric motor that turns the blower is a 12Vold DC motor. What ever DC is applied to the 2 wires that connect to the motor will make it spin. 2 volts it spins real slow, 12 volts, it spins real fast. Anything in between, it will be in between. The resistor block is the lowest cost way to make selectable speeds. A rheostat (power variable resistor) could be used, but they are big and expensive at the power level required for the blower. I looked up a quick guess one. 3" diameter behind the panel. Cost $40.00 if you buy 100. Probably would run hot enough to melt plastic at some settings. But that one can't handle the 10Amps max current. For that, you need the $360.00 per 100 pcs unit. The heater core is fed water from the engine, bypassing the cooling system thermostat. The temperature lever on the dash moves a big flap that forces the air in the blower box through the heater core or around it. A 555 with a BIG transistor would work, but not be much better than a linear regulator. My initial variable speed controller was similar to that. A switched mode controller is much more efficent. (Smaller heat sink) Go here, look up buck mode / simple switcher: http://www.national.com/ specifically: http://www.national.com/pf/LM/LM2673.html If the link doesn't work, search for LM2673. This chip is too small for the blower motor. It can draw 10 or 20 Amps at full speed. But it is a place to start if you want to see how a switcher works. For anyone interested in electronics, from beginner to advanced: http://www.nutsvolts.com/ If there is more interest in this, I can look for the schematics for the controller I built. If I remeber correctly, many of the parts can be scavenged from PC power supplies. Link to comment Share on other sites More sharing options...
joostvdw Posted September 23, 2006 Share Posted September 23, 2006 I have the same problem with my 88 XT (position 1 & 2 not working) but I do have a solution, maybe a bit daft but hey in the RC world there are variable motor controllers, ranging from 10A to 40A, If you would use the 20A/12V series, you can variable control the blower motor then add a simple 555 schematic to generate the correct pulse width modulated signal to control the controller and by using the original switch with 4 smaller resistor you can in turn control the 555 schematic to turn the motor to 4 preset speeds, or you can add a potentiometer (rheostat) and control the speed variable as I said, this may be a bit over engineered, but it will work and it will be exactly what you want, costs +-$40 depending on you skills and available parts... Link to comment Share on other sites More sharing options...
bgd73 Posted September 23, 2006 Share Posted September 23, 2006 If the resistor block is the only object variating the speeds... figuring the combos from switch to it, then diving inbetween them would be quite easy. The reducing is done for the 4 speeds, leave the same combo and break it down again, like binarically. Maybe just work with the switch end, leave the resistor alone. If it got too hot, paralleling a big resistor and figuring the balance unnecessary, becuase it will either work or not. I could put my finger on it until it bacame a focus of escape. The cheap unintentional result got me wondering how to use the coolness to get even more dynamical. The site with the switch mentioned ought to work, even tho it is only 3 a, the reducing is done. The only thing is, it is not truly rhesotatical is it? I saw multiple switch reducing, but switch and rheostat are different. Link to comment Share on other sites More sharing options...
DaveT Posted September 24, 2006 Share Posted September 24, 2006 Yes, the resistor is the means of varying the speed. There are 3 resistors connected end to end. One end connects to the full speed position of the switch and the +12V. The far end is the lowest speed, the 2 taps in the string are the middle speeds. To devide in between, you would have to add taps into the coils of the resistors. A switch will always have steps for each speed. If you get a switch with lots of positions, it can get to the point of being very little difference between such a switch and a rheostat / infinitly variable controller. Of course, such a switch would not be cheap, and you need more resistors. Link to comment Share on other sites More sharing options...
beataru Posted September 25, 2006 Author Share Posted September 25, 2006 it would be preety pimpin to have a variable speed fan in my subie .. you guys have tried everything.... Link to comment Share on other sites More sharing options...
joostvdw Posted November 2, 2006 Share Posted November 2, 2006 i'm trying to fix this right now on my resistor block, the middle one is broken, but the other ones read massive amounts of resistance, like, 1.1Mohms and stuff :-\ what the hell is wrong here? does anyone know the resistance values for all three coils? then I can just replace them with normal resistors and be done with it... Link to comment Share on other sites More sharing options...
bgd73 Posted November 7, 2006 Share Posted November 7, 2006 i'm trying to fix this right now on my resistor block, the middle one is broken, but the other ones read massive amounts of resistance, like, 1.1Mohms and stuff :-\ what the hell is wrong here? does anyone know the resistance values for all three coils? then I can just replace them with normal resistors and be done with it... Coincidentally, I am too. Second soob same prob. I just took apart one bad resistor, cleaned to a shiny spot the resistance materials to stop the crazy readings, away from the resistor block, meaning it is the only thing between the leads of meter. and also verified my ohm meter with a .1 on a 200ohm scale by touching the leads together. Here is what I come up with consistently: The tiny strand: .3 solid the middle one: .5 to .7 is as steady as I could get The big one: .8 to .9 solid on a 200 0hm scale I have not a clue what these numbers mean. I simply multiplied it by 200. I have never used an ohm meter until a soob with spfi. with my crazy math: the small to big would be 60 then 120, then 160 (or 180- which seems to fit a pattern) I am sure my findings are out there bizarre, there is a chance they aren't. I thought in this very thread someone posted the numbers already. I need to fix for the third time, with real high grade resistors accurate numbers. I found strangely the greater the resistance the faster the fan got- is this backwards? Having not a clue of the numbers I came up with are correct, I sought out some resistors (what the heck- they are cheap enough to be wrong) the big one nearest find = 178 (hmmm) middle= 118 smallest = 59 If someone could analyze the 200 ohm scale on the meter part to reassure me, I would try this with confidence. 5 watt or greater- given the area a resistor can fit, It can't be all that large. I just got a 25w 1k ohm resistor and it is at least a couple of inches long- so to proportianate this, maybe 10 watt for the block would fit- in a resistor cover, perhaps ceramic, like all the other safe and reliable ones. They even have a fireproof version, resisting correctly until the end of earth for all I know. Link to comment Share on other sites More sharing options...
joostvdw Posted November 7, 2006 Share Posted November 7, 2006 finally, a answer! the 0-200ohm scale simply means it can measure from 0 til 200ohms in that position, so the values you measured, the .3 .6 and .9 or something are .3 ohm, .6 ohm and .9 ohm that would add up, because the blower motor is 12V 140W or something, so to turn it at 1/4 power, you have to dissipate 35W in heat + it runs at more than 10amps, so the resistance has to be low to sink that amount of power, those resistors have to be HUGE. I think the only way to do this, is to link them parallel (that way you'll also get the correct, very low resistance you/we need) and put them upright, in the cool intake air, or perhaps with a cooling block, I wouldn't be surprised if they would catch fire if you don't cool them.. anyway, the values seem correct, and tomorrow, on my last day of vacation, I am going to give it a try. wish me luck. Link to comment Share on other sites More sharing options...
bgd73 Posted November 8, 2006 Share Posted November 8, 2006 finally, a answer! the 0-200ohm scale simply means it can measure from 0 til 200ohms in that position, so the values you measured, the .3 .6 and .9 or something are .3 ohm, .6 ohm and .9 ohm that would add up, because the blower motor is 12V 140W or something, so to turn it at 1/4 power, you have to dissipate 35W in heat + it runs at more than 10amps, so the resistance has to be low to sink that amount of power, those resistors have to be HUGE. I think the only way to do this, is to link them parallel (that way you'll also get the correct, very low resistance you/we need) and put them upright, in the cool intake air, or perhaps with a cooling block, I wouldn't be surprised if they would catch fire if you don't cool them.. anyway, the values seem correct, and tomorrow, on my last day of vacation, I am going to give it a try. wish me luck. excellent. I reassured myself too with more figuring: Thoughts of 12v resistors for fan R =59 ohmI= .203 ampsV= 12 voltsP= 2.441 watts R= 118 ohmsI= .102 ampsV= 12P= 1.22 watts R= 178 ohmsI= .067 ampsV= 12P= .809 watts they really don't have to be large and do get hot- The above math should be decent on a good motor.I watched 2 glow last night in the dark below glove box and it was below freezing outside. Assuming a bad amp draw on the engine, I took the blower out and found papertowel chunks and pine needles, put it back together thinking I would win the smaller resistors and it still failed my old resistor block. I hope it works, I will build two of them. . I found some flame proof ones, not hanging out in the open : http://www.micro-ohm.com/filmmetal/mor.html dimensions for above watts seem to fit. I made a mistake of getting a 25w 1k ohm resistor for a radio, the watts aren't the maximum of the line, it is the confusing part to me. A 2watt would have worked, all while radio puts out 50watt.... Link to comment Share on other sites More sharing options...
DaveT Posted November 8, 2006 Share Posted November 8, 2006 The post with the resistor values below 1 ohm is correct. The resistors are in series with the blower motor, and do not see 12V under normal operating conditions. (only if the motor was shorted out, or jammed so it could not turn) On the block I checked, they were .46, .6, and the small one is broken.:-\ Link to comment Share on other sites More sharing options...
beataru Posted November 8, 2006 Author Share Posted November 8, 2006 mine too... i havnt even gotten around to fixing those.... Still fixing vaccum leaks and header leak............ tomarrow.. tomarrow those things will fix tommarow with me........ Link to comment Share on other sites More sharing options...
joostvdw Posted November 8, 2006 Share Posted November 8, 2006 I have been digging around a bit today and fixing them by yourself is going to be a hassle, the resistors have to be huge and expensive to make sure they can take the heat, because they wil have to dissipate 40W, 80W and a whopping 120W heat to turn the motor at the correct RPM :-\ you could settle for something smaller, because they're actively cooled, but still, HUGE I'm going to order a new resistor pack from the dealer, only 33 euro's Link to comment Share on other sites More sharing options...
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