A/C Question. Can the temp switch cause problems.

[doug2060]

OK, I have been having trouble out of my A/C. I noticed that when I wiggle and hold the temp swich connector it works fine but when I let off it will start cutting on and off. I am referring to the temp switch on the intake. Can this affect the A/C?

Quick story: I have posted a question about the intake gasket too. I tried to remove the switch and it broke off. At 28 I am a veteran broken bolt extractor and drilled it out perfectly. Now I have to wait 2 days for Autozone to get me a new switch. Damn, I started out just trying to recharge the R134A and now I'm sitting here with the entire intake on my desk. WTF

[Woodie83]

That's it's whole purpose in life, to shut down the A/C if the engine coolant gets too hot. Yours must have failed internally. As long as you've got that intake off, clean your EGR passages. I'd get an intake manifold gasket.

[doug2060]

Thanks Woodie83. I'll get that gasket. Should I give it a thin coat of RTV? I didn't the last time when I did my rebuild but I didn't have any problems. I'm very lucky as far as the whole EGR thing goes. This car is without the EGR system. I hear those things are a real pain in the ass when they're clogged. I really got lucky when I drilled out that switch. It was a straight even shot. All I had to do was take a screw driver bend the thin skin that was left a bit and twist it out. I did knick the top part of the threads a bit but It looks like it's smooth sailing from here. I assumed for quite a while that the switch had issues because the temp switch would go from dead center to about 3/4 before the fan kicked on. It never caused a problem until recently.

For future reference: These switches are small and frail compared to most so be careful when removing. If they're old they will break easily. I tried to take one off one of my parts metro's and broke it off too.

Thanks again Woodie83 for your quick reply. I always like to check with you guy's before I go goofing something up.

[doug2060]

Problem solved! My temp guage still goes up into the 3/4 range before coming on but my A/C is working perfectly. I have read that it's not supposed to do that but I have two 1991 models that both do it. The one I drive the most has had a rebuild and I'm sure there is no serious problems but can anyone tell me definitively that it's not normal? I wouldn't say it goes all the way to 3/4 exactly up but pretty close. The only difference between other similar models is that my two 1991's do not have the EGR system.

[Woodie83]

There are water temperature sensors all over the car, each doing a different thing, some cars have four. There are two on the thermostat housing, one runs the gauge, one switches the fan on and off. You're familiar with the one for the A/C and most Metros have another very near that one that reports back to the engine control computer. Sounds as if your fan switch is a little bit late, no big deal as long as it never gets into the red, never hurts to renew connectors and grounds. Also, it's easy to get air trapped in the system. Jack up the front a foot, remove the radiator cap, and let it run for half an hour while catching the overflow and pouring it back in the top.

[doug2060]

Thanks Woodie I'll keep my eye on it.