AC compressor always work - SOLVED

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VASCO111
Posts: 3
Joined: Tue Nov 06, 2007 10:08 am

AC compressor always work - SOLVED

Post by VASCO111 »

As i wrote before the compressor AC works non stop , when AC turned - ON .
When you drive long time , the ICE is build on evaporator core and air in cabine is not enough cold .
Same time compressor work too much for NOTHING .
I got time and schematic from Toyota Matrix . Compared both Vibe and Matrix wiring , all was the same ,
BUT , on Pontiac Vibe the manufacturer instead Thermistor in AC evaporator core , simply replaced by 2 Kohm resistor , which run AC compressor NON STOP.
I went to scrap yard , took out Thermistor from Corolla 2003 , made a little hole in Box where evaporator is located . Instaled the thermistor and connected on place of resistor ...
Now my compressor work only when need same as Toyota Corolla ans Matrix
ihaveavibe
Posts: 96
Joined: Sun Jul 02, 2017 7:48 pm

Re: AC compressor always work - SOLVED

Post by ihaveavibe »

I'd like to check this on mine. Do you have a picture of where you tested the resistance?
Did you test at different temperatures?

It's really surprising if this is the case -- are you saying all Vibes have resistors, not thermistors? Perhaps your thermistor was faulty, or some owner prior to you replaced with a resistor?
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joatmon
Posts: 10018
Joined: Fri Mar 21, 2003 5:19 am
Location: SMC MD

Re: AC compressor always work - SOLVED

Post by joatmon »

I haven't noticed my compressor always running, or any issue if it does, but I did check and in my 03, in the connector that is on the left side of the front passenger footwell somewhere, where the wires should come out and go to the thermistor, there is just a resistor attached directly to the connector. Can't remember exactly where the connector is, but its the same one that has wires for the blower resistor, so you can find it by following those wires back.

Mine's an 03, I can't say if all Vibes just have a resistor, or perhaps just early ones.

Thanks VASCO for finding this, it is quite odd,
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ihaveavibe
Posts: 96
Joined: Sun Jul 02, 2017 7:48 pm

Re: AC compressor always work - SOLVED

Post by ihaveavibe »

I'm really starting to believe there is no thermistor because I can't find the sensor part on the supplier's websites!

This one has a blowup and there's only a temp valve but I think that's what the dash temp knob actuates.
https://www.gmpartsdirect.com/auto-part ... nents-scat

Would be great if VASCO showed a pic or a DIY!
jolt
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Location: Twin Cities, Minnesota

Re: AC compressor always work - SOLVED

Post by jolt »

Somewhere on this board someone said the Vibe and the Toyota's use a completely different brand of compressor, not the same. The belt that drives them is also different in length between the two car brands. If that is true then the AC cooling systems are not the same and probably do not operate the same. This would account for the differences in the AC systems. GM used their own stuff where they could, just like the radio's, the compressor's changed the AC system too.
ihaveavibe
Posts: 96
Joined: Sun Jul 02, 2017 7:48 pm

Re: AC compressor always work - SOLVED

Post by ihaveavibe »

I think this is true, the compressors and some of the components (ex the receiver/dryer) are different. I'm think that the systems use a different amount of R134a as well (based on the Matrix manual on madstyle and the sticker on my Vibe). But we are finding that not only the components are different, the system itself is also slightly different because GM simplified a thermistor to a "dummy" resistor. I.e. there's a component (and feature) missing on the Vibe. This might be model year dependent . (There was a TSB from Toyota AC002-02 that addressed a similar problem as the original poster's and the fix was adding a thermistor harness).
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