IHADAV8.com - Turbo Buick Tech, and Nonsense

Tech Area => General Buick Tech => Topic started by: shmed on June 30 2018, 07:10:49 PM

Title: A/c ?
Post by: shmed on June 30 2018, 07:10:49 PM
my ac compressor   wont cycle?   is there a  trouble shooting chart for this?\
the gauges say  I haved over 100 psi in the lines,  ecm sol fuse  is   good      if I try an jumper the switch on the canister  it doesn't turn on?   ideas
Title: Re: A/c ?
Post by: Steve Wood on June 30 2018, 07:57:27 PM
somewhere, I did a step by step walk through on AC troubleshootin g for the electrical side...don't see it at the moment

I would like to assume you checked the AC fuse in the fuse block as a starter.  You say you checked the ecm/sol
Title: Re: A/c ?
Post by: Steve Wood on June 30 2018, 08:09:24 PM
The wiring diagrams are here  http://www.ihadav8.com/forum/index.php?topic=3981.msg58921#msg58921 (http://www.ihadav8.com/forum/index.php?topic=3981.msg58921#msg58921)

but it would really help you to download the free copy of the manual and get all the info
Title: Re: A/c ?
Post by: TWild on July 01 2018, 10:50:06 AM
Try unplugging the connector near the bottom front of the compressor. It's the one that supplies power to it and it has two wires. If you undo the tape that's wrapped around it, you should see a small diode that connects to each terminal of the connector. Make sure that the small wire that comes off each side of the diode aren't touching. If they are, straighten it out and then re-tape it. Plug it in and give it a try. I had the same issue and doing this fixed mine.


Good luck,


TW
Title: Re: A/c ?
Post by: Steve Wood on July 01 2018, 02:20:19 PM
Here, I tried to find better copies  http://vortexbuicks-etc.com/ac_compressor_electrics.htm (http://vortexbuicks-etc.com/ac_compressor_electrics.htm)

Twild is right, that diode in the compressor plug is often a problem.

The rest can be easily traced with a meter or test light from the diagrams above-stay on the vin 7 circuits
Title: Re: A/c ?
Post by: shmed on July 01 2018, 03:47:56 PM
thank you very much fellas   ill   check these out next.    yes both fuses are good,   I changed them anyways to be safe.  back to the oven I mean garage..
Title: Re: A/c ?
Post by: shmed on July 01 2018, 03:57:20 PM
ok checked the diode  looks ok ,   does it matter which way it plugs into the compressor?
Title: Re: A/c ?
Post by: Steve Wood on July 01 2018, 04:11:28 PM
I never paid any attention to which way it plugged.  I am sure, originally the connector was made to go in and lock so I would line it up that way if you can see the catch.

 With the engine running and the AC control set to AC, I would go back to the light green wire in the cycling switch and see if it has power.  If it does, that means the problem appears to be under the hood.

If it has power, then I would put a jumper in the connector and see if you have power on the light blue wire on the relay.

If you do, jump across the relay from light blue wire to the dark green wire that goes to the compressor.  The compressor clutch should click and engage.  Does it?
Title: Re: A/c ?
Post by: shmed on July 01 2018, 04:44:40 PM
ok   so I tried both ways with the compressor plug no go either way...

the light green wire has power with engne running an with just key in on postion

I disconnected the relay (the one closest to the front of the car)   I have power   in 2 spots   with key on  an also when running.   when I jump the switch no other spots become energized.

Title: Re: A/c ?
Post by: shmed on July 01 2018, 06:17:09 PM
no  click no anything.....
Title: Re: A/c ?
Post by: Steve Wood on July 01 2018, 06:27:40 PM
So you have power on the light green wire.  When you connect that wire with a jumper in the cycling switch connector so that it now is connected to the light blue wire that goes to the relay....and then connect the light blue wire to the the dark green wire that goes to the compressor clutch...you get no click?

That would suggest the clutch is bad.  Too double check, jump off the battery positive pole to the dark green wire.

That should directly power the clutch so that it clicks and locks the clutch.  If it does not, you have a bad connection to the clutch or the clutch is bad.  Just to be sure of that diagnosis, I would verify the clutch is grounded via the ground side connection of the clutch because one of those pressure switches on the compressor could have failed and is not completing the circuit..

If you look at the bottom of the section diagram, the black wire on the connector goes to ground thru the high pressure switch.   You can jump the black wire directly to ground and see if that makes the clutch click before panicking about a bad clutch :D
Title: Re: A/c ?
Post by: Steve Wood on July 01 2018, 06:54:14 PM
Of course, you can be even more simple by pulling the connector off and checking for continuity between the black wire in the connector and ground using your meter...
Title: Re: A/c ?
Post by: shmed on July 01 2018, 07:10:49 PM
thanks steve….   would this work??\
\I pulled the connector off the compressor put power an ground to it   both ways    an nothing happened  would you say the clutch s arew bad?\
Title: Re: A/c ?
Post by: Steve Wood on July 01 2018, 07:35:38 PM
yes, if you put power and ground to the clutch coil terminals and nothing happened, I would say that is a clutch that has gone bad.It does happen

Dave, quit Missing and offer your opinion
Title: Re: A/c ?
Post by: Scoobum on July 01 2018, 07:55:04 PM
yes, if you put power and ground to the clutch coil terminals and nothing happened, I would say that is a clutch that has gone bad.It does happen

Dave, quit Missing and offer your opinion

Dave is missing is at his cottage for the long weekend...more than likely. C'mon Steve...wrack those brain cells!
Title: Re: A/c ?
Post by: Steve Wood on July 01 2018, 08:03:05 PM
if it does not activate the clutch when apply power and ground directly to the coil, then it must be bad...but, I am not there looking at it so I have no way to differ with his take on it :)
Title: Re: A/c ?
Post by: Just a Six? on July 02 2018, 10:07:04 AM
On the back of the compressor is that 2 wire Red Oval plug & I've replaced mine at least once with one from Casper's. If it's getting proper power try to wiggle it a bit back & forth with ac turned on car running & see if it kicks on for a second. I had to apply quite a bit of downward pressure on mine to keep the AC compressor running. I know it's Hot there so wear gloves or use a tool to wiggle it. I read thru your thread pretty quick so I'm just assuming you have power there or can jump it? Good Luck need AC this weekend.
Title: Re: A/c ?
Post by: daveismissing on July 02 2018, 05:36:52 PM
If he has applied a real ground and a good 12 volts right to the clutch then Shmed has bypassed the hi pressure cutout so I don't see anything else left to check. But when you reversed the leads I would have expected a very high current short thru the now positively biased diode?

PS: Apparently we now have a pet moose and he has the hots for my daughter's Nissan.
Title: Re: A/c ?
Post by: Scoobum on July 02 2018, 06:37:14 PM
Moose...Nissan ...Kinmount. It all makes sense...
Title: Re: A/c ?
Post by: Steve Wood on July 02 2018, 07:24:54 PM
so this is a how many Nissans could a moose mount in Kinmount if a moose could mount Nissans before a Nissan turned the moose into a mount in a Kinmount cabin?
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