Hey Guys,

I have yet another question for you. I went ahead and bought another distributor to deal with my cold natured problem. My old distributor's vacuum advance was very sticky and would hardly move. Well, now that I have the thermostat housing off replacing the thermo-time switch and the thermal vacuum valve, I noticed two other thermal sensors. From what I can tell, one of them tells the ecm to activate the fan on top of the intake, the other appears to work with the electric timing advance system. Do you guys know if I am correct in assuming this? That is what I could get from the shop manual. I would like to replace these two sensors while I have the housing off. The manual contridicts itself. One page says the 1983 has no coolant temp switch and then another section says it does. I looked for a coolant temp switch at Autozone, but those seem to require a plug from the wiring harness. The two in question on my car - one has a 3 inch long wire coming out of it with a male wire connector that connects to the harness and the other one only has a stationary male wire connector coming out of it that connects to the harness as well. Have you all ever tried to replace either one of these sensors before? I would appreciate your comments.

Thanks,

Colin

 

The other sensor in the housing that I didn't see you mention was the coolant temp sensor for the temp gauge. The coolant temp sensor for the ECU is on the passenger side of the cylinder head towards the firewall. It does indeed use an injector type connector. Its actually the same connector. The sensor for your temp gauge has only one wire.

So the list breaks down like this:
Coolant temp sensor (gauge): one wire
Aux. fan switch: one wire
Thermotime switch: injector type connector
and last is the TVV on the models so equipped

On some canadian models I believe the cylinder head temp sensor was actually in the thermostat housing, so it was then called the coolant temperature sensor (but still for the ecu)

 

Wait, so what's the aux fan switch sensor for? Our cars have a belt-driven fan. And for the models that have an aux. electric fan in front of the AC condenser, I thought only goes on when the AC is activated and not when the coolant hits a certain temp.

 

what about the injector cooling fan?

 

Yeah, its for the aux. cooling fan on top of the engine (the one that cools the injectors) on air conditioning equipped cars. It's the switch with the single white wire.

 

Hm, so do you guys think that aux fan switch sensor would allow easy replacement with an aftermarket temp sensor (ie for aftermarket gauges)? Or is the threading some unusual size?

 

"the book is only as good as the person reading it" if you catch my drift.

 

It's the same size as the regular temp. sensor for the gauges. Of course if you're going to replace the temp gauge, why not use the original sensor location? I can remember which size the thread is but I bought a Sunpro (or whatever that cheap parts store crap is) water temp gauge for my cross country drive and it had one metric fitting in it and it was the right size. But those two sensor bores are the same size. Thermotime is obviously a good deal larger. As for the TVV bore, I couldn't get that damn thing out so I don't know what size that thing is.

 

I'm installing an electric fan, which of course uses a temp-activated fan control. These fan controls usually take their reading from a probe that's stuck to the fins of the radiator. But I'm trying to think if I've seen a screw-in sensor for these fan controls (or if it's the same as a gauge's sensor). I would imagine it'd be more accurate for the fan control to take its reading from the thermo housing.

 

I'm sure you could find something like that. I was thinking you meant for an aftermarket gauge or something like that. What you're thinking makes more sense. Alls you would really need is a temperature SWITCH thats calibrated to switch on at the temperature you want.

 

Thanks for all the discussion guys. I appreciate all your help.

Merry Christmas Everyone...