95ONE

I didn't have a camera at the shop. Wish I did tonight.

Good description..

Right above DME/KLR Passenger footwell underside of dash.

Looking at it. 8 wires. Two 1.5"round porcelin Discs Two blades sticking out of each. Both sitting in a thin gauge aluminum holder. Other four wires attached to smaller round things on either side.

Sorry for lack of picture. Anyone?

The Thick wires leading to this are completely corroded and need to be removed or fixed.

Bri Bro

Your looking at the resistors for the Rad fan. The two large pucks are the 0.9 ohm resistors (used to lower speed of fan) and the two black parts are thermal switches that open if the resistors get too hot.

95ONE

Thanks again Brian.

beleive it or not. That was one of my guesses. They're just toast. (wires) I can't beleive how bad they are, or that the fans have even worked. Damn. MORE wiring.

Bri Bro

I just pulled one out of my parts to see if the unit could be used again. It had the same problem as yours, cracked insulation a couple of inches back from the terminals. The wires get a lot of heat from those resistors. If you want to spend a little more money, get some wire of the same gauge that has hi-temp insulation on it. Then put a six inch piece of it on the end of the original wire. The less expensive path is to cut off the terminal and put some heat shrink tubing on the wire, then crimp on another connector. Both will work, one for a longer time.

95ONE

I will certainly be doing the cut back to good wire and replace version

Bri Bro

Good luck, getting under there is a real pain in the back as you well know.

95ONE

yeah. had two herniated discs this past January.

Keithr726

https://rennlist.com/forums/924-931-944-951-968-forum/426996-ugh-cooling-fan-resistors-and-wires.html

Just dealt with this last week. In my opinion, the wires need to be competley changed but I didn't have time for that. I would also like to relocate them to the 87+ location near the cabin fan blower under the hood. 86 models have them under the dash with thermal switches next to the resistors to lower your chances of fire. I happen to have broke one of the switches and I'm still looking for a replacement. Right now they're hanging to the glovebox support bracket so I can reach over and record the temperatures. Yesterday I recorded 330 degrees! As soon as I find some new thermal switches I'm going to put them back and reroute the glovebox cooling pipe next to the resistors.


I'm a little confused as to how the fans work but I'm guessing they're always on high except when the relay sends the current through the resistors. Does this mean cars with thermal resistors use high fan speeds more often?

Bri Bro

Power (12VDC) comes into the resistor puck and then to the fan motor. In this mode, the resistor drops voltage before the fan motor and it runs slower (slow speed). When the water temp get high enough, the fan relay places a short across that resistor puck, all the voltage go to the fan motor and it turns faster (high speed). So, most of the time the fan runs on slow speed and the resistor are getting hot. Sorry my resistor pack was in poor shape, I don't want to send you a problem in the making. Did you get my Email on the thermal switches?

I have never measured the resistor puck temperature but 330F sound high. Your fan motor could be pulling too much current. I would check it.