I've become suspicious of my Temp II sensor, so I thought I'd test it. However all of the good "What's Under The Hood" diagrams are for the '87+ engines. In the pic below, sensor D is the gauge temp sensor...what are A, B and C? I know one of them is Temp II, but I'm not sure which one, or what the others are...

 

B = Temp II

 

C = Fan switch
D = Temp gauge
A = TPS

 

B is temp 2.

C is intake air temp switch, which will operate the fan even if the car is off --- if underhood temperature is very very hot. With your extremities clear of the fan, remove the two leads and touch them together for fan operation. This particular subcircuit is one of several that will instigate the fan, and this one actually routes through a resistor located at passenger front right near radiator as it operates at a reduced speed.

As I recall, A is an extension wire from the throttle position sensor and that fixture is where that wire mates with the engine harness. I'd look, but the 32V cars here are under 14 inches of snow.

 

BTW, oil is leaking from the (hardened) breather hoses at the base of the oil fill assembly on that car and blowing oil mist onto the top of the engine.

 

Thanks guys. Very helpful!

For C, I assume you mean the aux fan in front of the condenser? It's weird because that thing also has a temp sensor on the radiator.

For Temp II, my connector boot has a crack or a slice out of it. Do I just pry that back to expose the wires? Or is there some weird clip I need to be aware of? I suspect I'll be replacing it but I want to test it first.

 

The Temp II is like most of the Bosch style plugs used under the hood. I have found the easiest way to deal with them is to use a small pick and unclip the wire retainer first, then the plug is easy to pull apart. If I'm trouble shooting a circuit I'll leave the retainers off till I'm done to make it easier.

 

Besides the intake air switch, there are other additional sensors / subcircuits hat independently trigger the front-of-condenser fan. Look for them on 85/6 wiring diagram

 

Personally, I'd just test the sensor at the EZF and LH connectors next to the fuse panel. Don't risk breaking your brittle engine bay connectors if you don't have to.

Plus, if its out of range at the connector, then you test at the sensor anyway, you'll know whether its a bad sensor or bad wiring in the harness.

There's a pinout diagram floating around somewhere...

 

From what I've read while trying to figure out what is wrong with my 86 these sensors are bad about failing on the cold end and showing an open circuit. I tested mine in the car then pulled it out and froze the sensor and rechecked it. I then put it in a pan of hot water to check it in the hot condition. I then reinstalled it and checked the value at the sensor. Once all of that checked out I tested it at the EZK/LH to verify the entire circuit. Be careful and only look at the 85-86 schematics. Most of the LH trouble shooting is for the 87+ which use a different pin layout.

 

oil hose..or compression out the filler?

Your intake clamps are bashful- facing backwards.

Outstanding GB front fuel hose.

 

Good idea about checking the temp sensor at the fuse box, I'll look into that.

I'm not responsible for the intake clamps, I haven't touched them yet! I'm not sure what the oil hose comment meant though...

 

FWIW, I measured the Temp II resistance to ground after putting it in the fridge, and then with the car up to operating temps. Cold, I got 2K - 3.5K (both sides) and hot 270-320 or so. The cold side is within spec, the hot side a little low...which is odd, since my issues were cold. I'm guessing that the Temp II is probably not my problem....

 

Check the values at the EZK and LH to verify you don't have a broken wire. Make sure to look at the pin out for the 85-86 cars since the pins are a little bit different on the later ones. The value there should be identical to what you get under the hood.