Grand AM Problems

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  #1  
Old 05-13-06, 02:37 PM
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Cool Grand AM Problems

Hello, I have a 1999 Grand AM SE 3.4L. My airconditioner and cooling fans are not working and I am wondering if the problem could be related?? Today I got my wife to turn the air-conditioner on and off while I was under the hood. The clutch did not engage. The engine actually sped up when she turned it on and drew down when she turned it off! (I double checked this) I also could hear a relay clicking when she turnrd it on and off. I checked the AC relay and it tested fine. I also put a jumper wire in the relay socket and the clutch kicked right in. I also checked the control circut and I did have 12 volts on the positive (in the socket) when I turned the ignition on. My cooling fans also are not working, again I checked the relays and the fans run if I hot wire them. One question I do have according to my manual the control circut should have voltage when the ignition is on and I don't. The cooling fan 1, fan 2, and cooling mode relays are on the same circut and none of them have voltage when the ignition is on. Where would I start trouble shooting this? I thought I checked all the fuses. Any help would be greatly appreciated.
 
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  #2  
Old 05-13-06, 04:41 PM
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Most likely low 134a in your A/C system. The clutch will not engage with low freon, also the fans will be out of the system, no A/C no need for fans. The idle change is because the PCM thinks the A/C is on because you turned the switch on, PCM's are kind of dumb.
 
  #3  
Old 05-14-06, 06:20 AM
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If you don't have power to the relay sockets for the cooling fans with the key off, one of the maxi-fuses has blown, or the maxifuse has lost it's source of power.
Does the system cool normally when you jumper the relay socket and the compressor engages? It should cool momentarily even with no cooling fans, but then start to lose it's cooling capacity once the need for the fans arises, as in, high, high side pressure. (p.s. your diagnostic strategy is impressive.Techs who do this for a living wouldn't have gotten as far as you have, btw.)
 
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Old 05-14-06, 04:42 PM
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Originally Posted by bigguy05641
(p.s. your diagnostic strategy is impressive.Techs who do this for a living wouldn't have gotten as far as you have, btw.)
Being that you mentioned it...I thought the same thing. I thought, "Gee...this guy is a pretty sharp diagnotician, and you'd think he'd get it all solved himself."

Sly,

Out of curiousity, are you are car buff, or are you an electrician or an appliance repair or HVAC person, or are you someone that has good basic instincts on how to check things?
 
  #5  
Old 05-15-06, 07:20 PM
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No I am not a mechanic or anything like that I just enjoy trying toubleshoot. I don't have any way of checking my 134a level but I do know that when I manually jumped the AC clutch I let it run for about 20-30 seconds and the air cooled right down. I think I didn't make myself clear when I said I don't have power in the fan relay socket. (I'm not sure of the correct terms to use to describe this so I'll do the best I can) I do have power to the contacter (Relay terminal 30) with the key off but according to my manual (I have a Haynes) there should be 12v + on the COIL terminal (terminal 85) with the key turned ON. The other coil terminal runs down to the pcm according to my skematic. So I am assuming the pcm controls the relays by switching the negative side of the coil circut? I am checking this with a test lamp with the lead clipped to the negative battey terminal. Like I said on my AC relay I do have power at terminal 30 with the key on but on the fan relays I don't. I did double check the fuses tonight. Also I failed to mention that the fans also do not work when the engine gets too hot. Thats when I first noticed they were not working. When I idle for too long it starts to overheat but the fans don't come on. I did have to question my temp sensor but I guess I would first like to try to figure out why I don't have power at the coils. My schematic is not to clear about where that power should be coming from. Could anybody help me on this? As an afterthought, I have to question my manual in the fact of power being at the coil terminal on the fan relays only when the key is on, don't the fans sometimes continue cooling evan after the ignition is off? Or am I remembering my old Honda? Thanks!!
 
  #6  
Old 05-16-06, 12:02 AM
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Just thinking but it's possible that your a/c will not work if there is a problem with the radiator fans not working if turning on the a/c is supposed to activate the radiator fan, so you may not have an a/c problem if you get the fans to work.

Is there a fuse link that goes to the fan relays that you could have overlooked? If you can, try connecting 12v to the fan relay where you say youre supposed to have it at terminal 85 with the relay installed. You may have to splice into the wire. Radio shack sells terminals for this..... http://www.radioshack.com/product/in...entPage=search
Then turn on the a/c and see if it and the fan works.

It sounds like power to the relay should be coming from the ignition switch. There may be seperate fuses for each of the 12V relay fan connections. Can't say for sure, I don't have a schematic.
 
  #7  
Old 01-12-07, 05:11 PM
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Hey guys,
Does anyone know if he got this fixed?

I'm having the same problem.

I found out that if i disconnect the fan/temp sensor, my fans would come on. I'm thinking it's my PCM, but I would like to hear what others think.
Thanks!

George
 
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