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Ok, the A/C is on the fritz, and they are telling me it is the PCM program not turning the fan on when the A/C kicks, and the A/C is reading over 400 something on the high side (I am not savvy in A/C techno-speak)
They don't want to run diag. on it because of the tune & supercharger stuff. How far can they go without hurting the tune? Can they diagnose without reflashing safely?
Over my head here, and the 95+ temps are cooking my head.
:help: :help: :help:
Thanks in advance guys,
S.C.
You have electric fans and the PCM isn't triggering the fans? Did Allen turn the fans on? Are you sure it just isn't a bad relay?
<div class='quotetop'>QUOTE(RedHeartbeat @ Jun 28 2006, 03:17 PM) [snapback]56536[/snapback]</div>The fans have always worked properly.Quote:
You have electric fans and the PCM isn't triggering the fans? Did Allen turn the fans on? Are you sure it just isn't a bad relay?
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Now if they aren't working at the same time the A/C has been messed up, I haven't noticed that.
FWIW, the A/C isn't working right on idle at initial startup, or after it has been sitting. It seems it cycles quicker than it should, and starts to blow hot air. If I drive on the road or highway, it cools fine after a minute or so.
Just got off the phone for the exact wording from the dealership:
"cooling fan not coming on with compressor, high side over 450psi"
I have no idea what that means. I know for sure the fan or fans come on high when it hits 210* because I can hear them. Now I am not sure if the single fan was cycling with the A/C or not (I am a bad, bad person for not paying attention).
I would take it somewhere else that deals in A/C only. Im sure its a wiring problem and not the pcm. Your efans are not factory right?
The high side pressures will go through the roof if the fans aren't running. The air flowing over the condensor should bring the high side pressure down. If it were here, I would turn both fans on high and watch the head pressure, it should come down fast.
:imwstupid: They got that part of the diag right fans def not comming on and why its blows warm then gets cold when you get on the highway...
I did notice that when the truck got hot enough for the fans to come on high (or maybe just one of two was on high), that the AC did seem to work right even if it was sitting still.
So the fan not cycling could cause that much trouble??? If it is the fan, any ideas? Relay??
Maybe you hooked into the wrong wire when hooking up the fan wiring harness. I know Allen has provisions to turn on the fans with the a/c, seen it happen on USE2BFO's truck. It's easy to connect to the wrong wire since there are more than one green wire in the harness.
i just love how its such a hassle to get your truck taken care off at a dealeareship when its modded and they always blame it on it. :thumbdown:
<div class='quotetop'>QUOTE(RedHeartbeat @ Jun 28 2006, 06:27 PM) [snapback]56568[/snapback]</div>Nope Red, it has been working. This just started recently. They have been in there a while. Could a relay go bad & cause it not to work?Quote:
Maybe you hooked into the wrong wire when hooking up the fan wiring harness. I know Allen has provisions to turn on the fans with the a/c, seen it happen on USE2BFO's truck. It's easy to connect to the wrong wire since there are more than one green wire in the harness.
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Of course this is all speculation since it isn't here for me to look at. :bash:
Hmmm... have you had a new tune recently? Is this the exact same tune you had before when it was working? Sounds like a wire or relay isn't working/connected.
He is correct about the high side of the A/C it will shoot through the roof if the fans aren't pulling air across the condensor, the reason it starts to cool when your moving is air is going across the condensor. Sounds like you have a bad relay or pin # 42 came out of its socket. have you tried to wire the fans up direct to the batt. to see if they work, if they do then start back tracking the problem from there. good luck.
Update...I had the service guy go check for me, and the fan is not cycling on/off with the A/C. But one of the fans is coming on when it gets hot enough.
So, it sounds like a relay, wiring or bad fan .
Which "Stealership" is your truck at? :tantrum:
Hewlett Chevrolet in Georgetown. They actually are good guys.
Red & VV8, you guys called it right, it was a bad relay. Everything seems to be okay. I am concerned the relay is melted @ the #30 tab (for those of you playing along at home with the Nelson harness).
Put a new one in, worked fine, so it shouldn't be a short. Could overload do it? If so, how do you cure overload???
Bigger relay. Run a 30 amp minimum. I run 40s. Then again I run 8 guage wire for fan power and grounds. Overkill never leaves you stranded.
<div class='quotetop'>QUOTE(RedHeartbeat @ Jun 29 2006, 03:37 PM) [snapback]56691[/snapback]</div>HMMMM, well these are all the relays included in Allen's harness. I wonder if anyone else has had this problem??Quote:
Bigger relay. Run a 30 amp minimum. I run 40s. Then again I run 8 guage wire for fan power and grounds. Overkill never leaves you stranded.
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Sometimes it's just a loose connection at the relay. I haven't seen Allen's relay connectors but the ones I bought off of ebay almost landed in the trash because the connectors wouldn't carry a 10 amp load. Now I only use them to trigger light weight power loads. All my fan relays are direct wired with spade terminals. I can't just R&R my relays due to being direct wired though.