My a/c quit in December (coolant leak) which I plan to fix but am waiting for nicer weather. Unfortunately though, when the a/c quit the cooling fan seems to have quit too.

For whatever reason it has always only come on when I turned the a/c on, so if I was sitting in traffic and the car got hot I would just turn on the a/c the fan would kick on, an I would be good. Now it doesn't come on at all though cause I can't turn the air on.

Any ideas?

thanks

 

Curious, did this happen prior to your installing your 180 Degree Superstat Thermostat?... If it did, your car's ganna get quite hot before any cooling systems kick in...

If not, also check your coolent sending unit, it's like a plug thats inserted directly into the block. If it's bad say good bye to your fans. Easy fix though.

 

don't know about the thermo, the sig is old and I don't run the JET anymore so I guess I could switch it out.

Does the sending unit on the block control the fans? Easy change?

 

It doesn't nesicarily control them but it does one of two things...

It tells the fans when the engine is hot enough and kicks them on, meaning if its broke then your fans will never know your engine is cooking and will just sit there and let it all go to h*ll.

OR/AND...

It tells your temperature gauge how hot the engine is, meaning if its broke it could simply be telling the gauge the engine is hotter than it really is, meaning although the gauge is at 3 quarters and the fans still arn't on, the real temperature may only be at what the gauge would represent as the quarter mark, meaning your engines actually still to cool for your fans to kick in. This happened to us on our dads Z, we tore the whole car up looking for a possible shortage to the fans because they wouldn't kick in, as it turned out that unit was fried and the gauge was reading two quarters off, telling us the engine was hotter than it really was making us think we're overheating because our fans wern't coming on when in truth the fans worked fine... the car just wasn't hot enough.

Also on the Z, if we disconnected the smog pump the fans would come on and stay on automaticly.

 

thanks, thats a good starting point

 

The cooling fans come on with teh AC in order to keep the head pressure down. If your system had a leak and there is no more pressure in it then turning the ac on will no longer turn the fans on due to a lack of pressure.

The fans should still come on during normal collant temp range witch will be fairly high. 220-230 range. is it getting to that point or is it still not coming on?

 

If I am sitting it is getting past the 'halfway' point on the gauge without coming on -- at the point I always begin driving again to cool it off

 

The fans on my Dads Z28 never kick in till just before the 3/4 point... then it cools down to about half and repeated process...
I think the sending unit is bad...