ystrdyisgone Posted January 12, 2013 Share Posted January 12, 2013 I finally fixed my heater blower level problem tonight in my 87 GL wagon. I have seen talk of many others on the board with this problem. Decided to make an official fix it thread since I haven't seen one. Not only do the internal connections of the switch wear out, but there is another assembly completely separate from this one that affects heater function. There is a resistor assembly just above the passengers feet held on by three screws which consists of a small circuit board, with rows of spiral wire resistors. This is what actually controls the speed of the fan. There are three coils, which progressively grow in size. The smaller one is fan setting one, the medium, setting two, large, 3, and number 4 is full power, no resistor. As these get old, the thin wire breaks, much like a filament in a light bulb, as these resistors are lost, so are their appointed speeds. This is why many of you have the number 4 as the only working setting. Now I just replaced this with a spare resistor assembly from an 89 DL. Expose the assembly by removing the three plastic pressure fit screws in the panel below the glove compartment. Remove panel and look under. A 3x1 inch black plastic component with an angled arm and a set of wires running from it is what you are looking for, it's fairly obvious. Remove these screws and unplug the unit. Swap in the new one and do everything in reverse. Voila! All 4 heater settings:headbang: If you don't have an extra resistor assembly, you may very likely be able to fix your existing unit by resoldering the resistor wire to its original state. It is likely soldering some modern resistors to the circuit board would provide for a longer lasting fix to the problem. If this doesn't entirely fix the problem, it is likely your actual switch mechanism is the culprit. Hope this was helpful! Link to comment Share on other sites More sharing options...
kerandt Posted January 12, 2013 Share Posted January 12, 2013 Interesting. All this time I thought it was just the switch. I have speeds 3 and 4. Now I just need to check out this resistor box you speak of. Cool beans! Link to comment Share on other sites More sharing options...
-tombba- Posted January 13, 2013 Share Posted January 13, 2013 I once fixed mine with a new resistor coil wires. I also had jsut the speeds 3 and 4. It's fairly easy to do the new resistor coils to it. I did it by wrapping resistor coil wire around a different szed pencils and cheked that I had similar amount of wire and similar thickness of wire in my new one and then just soldered the new ones on their places. I would not fix the old ones by soldering them since the resistor wires may get hot and the solder might melt in that case. I don't have any pictures of this operation but it's fairl easy to do when and you get the point when you see the part itself. Link to comment Share on other sites More sharing options...
kerandt Posted January 14, 2013 Share Posted January 14, 2013 Looks like dog hair got into mine. And at first I didn't see the "blower resistor". It kind of blends in with the duct work. Link to comment Share on other sites More sharing options...
tractor pole Posted January 14, 2013 Share Posted January 14, 2013 (edited) I have the same problem. Does anyone know the resistor values? So you could rebuild the resistor pack. Wait i just read tommba's post again... going to radio shack on the way to work. Edited January 14, 2013 by tractor pole add info Link to comment Share on other sites More sharing options...
robm Posted January 15, 2013 Share Posted January 15, 2013 Aftermarket resistors have to be huge to dissipate enough heat. This has been done, but it is a pain. A search should turn up the details. Fixing the existing one is harder than it looks, as the resistor wire is very hard to solder. If the resistor is burnt out in the middle, there is not much you can do to fix it. Maybe squeeze it together, and hope it reconnects? It may work for a while. If it is burnt out close to the connection, it may be possible to resolder it. Scratch the wire to try and get to a clean, solderable surface, heat the existing blob of solder, push the wire into it and add more. Pray lots! I got a couple of years out of a fix like this. Link to comment Share on other sites More sharing options...
ystrdyisgone Posted January 15, 2013 Author Share Posted January 15, 2013 Nice work on the pics kerandt, I'm sure it will help save others some confusion. Mine had dog hair too, as well as a couple pennies resting on it. The design seems weird to me, I don't understand why the resistors have to be exposed to the moving air within the blower ducting. Maybe it has something to do with temp control as well? Link to comment Share on other sites More sharing options...
987687 Posted January 15, 2013 Share Posted January 15, 2013 Nice work on the pics kerandt, I'm sure it will help save others some confusion. Mine had dog hair too, as well as a couple pennies resting on it. The design seems weird to me, I don't understand why the resistors have to be exposed to the moving air within the blower ducting. Maybe it has something to do with temp control as well? Correct. Using a resistor is an EXTREMELY inefficient way of dissipating current for a high load. So they create A LOT of heat. It is, however, an extremely simple design, and since power draw isn't really a concern, that's how it's done. But since it needs a lot of cooling, it has to be in the ducting. EJ ones actually have a cage around them for better protection. I keep meaning to grab a couple EJ ones and see how I can adapt it to work in the GL. Every GL I've ever seen in a junk yard has a blown resistor pack, it's extremely frustrating trying to get a good used one. I haven't even seen a junked GL for a while up here. They've all rusted out. One thing I have considered as a fix is just doing a solid state circuit like a PWM board with preset resistors that the heat selector choses for the PWM. It would be a plug and play solid state fix to this stupid problem. Because honestly, I'm tired of only having three and four. 1 Link to comment Share on other sites More sharing options...
kerandt Posted January 15, 2013 Share Posted January 15, 2013 (edited) Here's some more reading for those who really want to dwell on the situation. Resistor block wattage http://www.ultimatesubaru.org/forum/showthread.php?t=18580 Blower motor resistor pack http://www.ultimatesubaru.org/forum/showthread.php?t=41911 GL-10 Blower Switch http://www.ultimatesubaru.org/forum/showthread.php?t=64761 Heater blower missing speeds replace http://www.ultimatesubaru.org/forum/showthread.php?t=75738 Edited January 15, 2013 by kerandt Post Titles . . . 1 Link to comment Share on other sites More sharing options...
Wayback Posted January 15, 2013 Share Posted January 15, 2013 You can still get a new blower resistor pack, costs about $40, part# 72083GA070 Link to comment Share on other sites More sharing options...
ystrdyisgone Posted January 16, 2013 Author Share Posted January 16, 2013 Guess I should have checked out the USRM first... http://www.ultimatesubaru.org/forum/showthread.php?t=112986 Link to comment Share on other sites More sharing options...
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