I have an 1986 iroc-z TPI. When I turn on my ac the car will start to over heat horribly, and it trips the service engine light. Then if I turn on the heat first it will just trip the service engine light, But the car will still over heat . But if i had the ac on and just befor the car starts to over heat , I put on the heat . And it will just trip the service Engine light and not over heat, And I will loose power. What should I do to stop This from happening?? Thanks!! :lala: :lala:

 

I think you'd get more answers on the cooling board, but...

1. Make sure you have the air dam underneath the nose
2. Make sure your radiator hoses aren't collapsing
3. Clean the radiator of all bugs and other crap
4. Check your thermostat
5. Check your coolant sensor
6. Make sure your coolant/water ratio is right and that you have enough fluid

And if all else fails, just screw it and don't use the a/c! lol

 

What error codes are you generating? It's easy to find out with no more tools than a paper clip and your ignition key.