daeron Posted July 30, 2006 Share Posted July 30, 2006 okay, 87 GL-10, spfi EA82, non turbo, automatic if that matters... i got the car from my brother, he had at one point replaced the stock electrical fan with an aftermarket slim line.. this fan has the stock plug grafted onto it, but only on one wire. the hot wire. The groundwire coming out of the fan is currently mounted on the bolt that holds the vacuum lines down on the thermostat housing. My electrical fan comes on when i turn the key to accessories.. basically, when ANYTHING switched by the key is on. I recently got a stock fan to put in there (the slim line has a very small footprint) and when i plugged it into the cars wiring harness, it failed to come on.. not with the key, not when the car reached operating temperature, (three bars on my digidash) not with the AC. so, how does this system work? i am assuming that somehow the ground is switched by the thermoswitch in the radiator, but if that is the case then why is the power dependent on the key? I would like to restore the fan to factory operating conditions, just to make sure that box gets a check mark in the "correct" column. how do the fans on these cars operate? is it supposed to come on with the AC, or at a temp threshold? do they normally continue to run after the car is shut off, if it is hot enough? I got a new radiator out of a junkyard and it had a thermoswitch in it with a different plug than mine.. i dropped it in boiling water, but at no temperature (85-212F) did it register ANY continuity between the two poles of the switch. that means its bad, right? if i get zero continuity out of the one in my radiator, its bad right? the FSM .pdf i have has details on testing a "thermometer" according to resistance, but i think thats referring to the temp sensor connected to the guage on the dash. the big questions are 1. thermoswitch test.. zero continuity == bad, right? 2. STOCK configuration, fan is wired/switched, how? and comes on/shuts off, when? 3. am i fussing over nothing, and should i just cut the groundwire on my stock fan and wire it as the existing aftermarket one is? and 4. If i do so, i could put a thermoswitch into that bung to power a relay switching the slim-line, if i should opt to use THAT in place of my clutch fan, correct? anyhow, thanks for the answers. shawn Link to comment Share on other sites More sharing options...
mikeshoup Posted July 30, 2006 Share Posted July 30, 2006 If I remember, the thermoswitch closes at 230 or there abouts. Boiling water trick doesn't work. I'm assuming you're talking about the stock electrical fan. It comes on when the thermoswitch is closed, or shortly after the A/C comes on. It doesn't run with key off, only with the key in ACC, or ON. Link to comment Share on other sites More sharing options...
NorthWet Posted July 30, 2006 Share Posted July 30, 2006 Thermoswitch activates closer to standard t-stat temp, around 195-205F, and switches off around 180-185 IIRC. EA81-style switches grounded through the radiator, but EA82 just passes through and needs a separate ground; can't recall whether switch is between power and fan or after fan. As Mikeshoup typed, fan is only energized with ignition on. Several people have used the T-switch to activate a relay to control their fans, but make sure the relay is protected from the weather and splashes. Link to comment Share on other sites More sharing options...
daeron Posted July 31, 2006 Author Share Posted July 31, 2006 OK.. so just to clarify, if i get no continuity across the terminals of the thermoswitch when it has been sitting in boiling water at sea level (212) then its bad.. and if i have a bad thermosensor, or if my car is not up to full enough temperature, then i will never see a completed circuit for the ground at the stock fan plug, correct? basically, i need to short circuit the plug on the car for the thermoswitch, and it should establish the ground at the stock fan plug that I am missing? if it does, it means i need a new thermoswitch, and if it does not, then i have "other issues" and should probably not worry about it, and just hack the groundwire on the stock fan, and ground it like i have it set up now. right? thanks again Link to comment Share on other sites More sharing options...
daeron Posted July 31, 2006 Author Share Posted July 31, 2006 well, quick update, i just went and checked for resistance at current operating temp (3-4 bars on the digidash guage, im imagining about 175??) but then again, i checked the other unit (out of junkyard radiator) at full rolling boil and it was good.. but not the first time i tested it, at 95% boil (large bubbles forming rapidly on bottom of saucepan..~190+?) SOO i went ahead and shorted out the plug that goes on the thermoswitch and, bingo, the plug for the stock fan is on.. so should I just hotwire the plug on the thermoswitch? i can make a jumper readily enough. i cant imagine the jumper would need to be a large gage wire, either.. but again, if i am wrong, please correct me. thanks once more Link to comment Share on other sites More sharing options...
NorthWet Posted July 31, 2006 Share Posted July 31, 2006 To answer your main question, just jumpering across the connector with a wire with similar gauge to the ones in the connector should work. I have used a paperclip on several occasions, and keep one under the hood for emergencies. To comment on your water temperatures, the state of water in a pan is hard to determine. (Boiling at the bottom of the pan just indicates that that spot of the bottom got hot enough to vaporize water.) Best to use a thermometer. Link to comment Share on other sites More sharing options...
daeron Posted July 31, 2006 Author Share Posted July 31, 2006 no thermometer available... and both times i did take it off the heat and stir it to ensure homogenous temperature in the water at least.. but before i read your post i realized i had neglected to factor in direct heat transfer from the metal of the pan.. and other holes in my testing process. I think i am going to hotwire the thermoswitch plug, put the stock fan back in place and plug it in, and use the thermoswitch to switch the aftermarket fan currently on the passenger's side once i get wiring to move that over to where the clutch fan is the aftermarket fan fits in the clutch fan shroud VERY well thanks, i do alot more work on my car in my head than in the driveway.. so the forum here is a good sounding board for me. I like to think things through before i make mistakes on my "first try...." ive found it cuts down on the number of "second tries" necessary :- ) :banghead: Link to comment Share on other sites More sharing options...
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