Radiator fan problem (81' tercel)

[stayparanoid]

So i have a problem here. I live in Austin, TX and i noticed the other day that the radiator fan was not turning on at all. It stays cool while moving but in traffic it wants to climb quickly. Fortunately, I caught it before it overheated too much. The fan is loud so you know if it isn't turning on. I started by changing the relay, it didn't run. Then i changed the temperature switch, still nothing. I pulled the temp switch to see if it would turn the fan on and it didn't. So from there i put some jumper wires from the battery to the motor and it did kick on, so i assume that the fan motor is good. i have un-raveled a lot of the wiring conduit and from what i am seeing, everything looks good. very clean actually.

i am at a loss here. i don't know if these things happened at the same time but i noticed that the blower fan motor does not turn on either. it definitely did a week or two prior to this situation though. also i dont know if this has anything to do with it or not but the day the fan stopped working, i also did a tune up to the car, adjusted timing, fuel mixture (weber), and idle screw. it was working when i was doing that because i was waiting for the fan to kick on before i tuned it.

there isn't a lot of information out there about my year of tercel so i take everything on here with a grain of salt.

any of you have any suggestions so i can get Saxon back on the road?

[slimdude85]

While I’m not sure of your problem, I also have an ‘81 Terc and have a Bentley manual that has a pretty good wiring schematic. Without looking in depth, the only thing that I can think of that may cause both the blower and cooling fan to stop working is if they share a common ground that went bad. Any way, here ya go. If this doesn’t work, I’ll try to get some scans tomorrow.

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[slimdude85]

Separate posts it is...

[slimdude85]

Number 3...

[slimdude85]

Last one....

[slimdude85]

Did you change the coolant temp switch on the engine or the fan switch in the bottom of the radiator?

[Petros]

I do not know, but there may be a fuse to check too. I know it is easy to forget the obvious.

[stayparanoid]

Did you change the coolant temp switch on the engine or the fan switch in the bottom of the radiator?

I'm definitely going to check out these wiring diagrams. I replaced the fan switch at the bottom of the radiator with a new aftermarket one. should i replace the coolant temp switch too? wouldn't have thought to try that. it appears to be reading temperature properly.

[stayparanoid]

I do not know, but there may be a fuse to check too. I know it is easy to forget the obvious.

to my knowledge, i dont think there is one. at least nothing labeled radiator fan. it could be tied into something else though.

[stayparanoid]

I do not know, but there may be a fuse to check too. I know it is easy to forget the obvious.

although based on the pictures posted there is some sort of fuse. i'll have to check into that.

[slimdude85]

The temp sensor in the head is for the gauge in the cluster. As long as the needle is moving, it’s working, so there’s no need to replace it.

[slimdude85]

Ya might look into that fusible link between the fan relay and ignition relay. Fusible link is just a section of wire that’s designed to burn up, instead of the primary wire, in the event of too much current being drawn.

[stayparanoid]

Ya might look into that fusible link between the fan relay and ignition relay. Fusible link is just a section of wire that’s designed to burn up, instead of the primary wire, in the event of too much current being drawn.

is the fusible link just a little wire in a loop that is attached to an wire connector? i see one of those and it is white. how can i check to see if that is the problem?

[slimdude85]

I’m not exactly sure what it looks like, to he honest. I noticed it in the diagram. It’s between where the wire transitions from brown to white. Typically when a fusible link goes, its burns. 99% of th time you should be able to tell just by looking at it. Although it is a 37 year old vehicle, so there’s no telling if it failed as intended. With a multimeter, you should be able to test for continuity.

[stayparanoid]

Still never found a solution to this. I cannot find anything wrong in the wiring. I have to assume that it's a ground or something.

Anybody have any ideas on putting it on a manual switch for now? Not sure how I could wire that up