AC

SweMos

New member
Jun 26, 2020
1
1
Hi
Got myself a Buick Roadmaster Estate Wagon 1996,
AC won't turn on, the clutch works if I remove the relay and put a wire there.
I have filled it with r134 so the pressure is fine.
It won't engage if I bypass the pressure switch either.
Seems lika an electrical problem but where should I start?

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Shortfuse

Member
May 15, 2020
82
18
First place to start is to check you fuses. Second place after that since you know your compressor will run is to make sure the relay is getting the command to turn on the compressor. Your relay should have four terminals, when it is commanded on it should 1 power and 1 ground as well as the a terminal providing + current to be sent to the compressor. If you are missing any of these you need to figure out which one and go from there. I will post a schematic to help. You can also contact me for me detailed help. The first diagram is for automatic ac the second is for manual ac.
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MikeThomas1954

New member
Jun 27, 2020
20
3
Little Rock AR
Hi
Got myself a Buick Roadmaster Estate Wagon 1996,
AC won't turn on, the clutch works if I remove the relay and put a wire there.
I have filled it with r134 so the pressure is fine.
It won't engage if I bypass the pressure switch either.
Seems lika an electrical problem but where should I start?

Skickat från min VOG-L29 via Tapatalk
buy the factory service owners manual It can be 800-900 pages, it has step by step all the info the pro mechanics DONT know
 

Shortfuse

Member
May 15, 2020
82
18
It means details step by step the pro mechanics will tell you they do the repair in a different way,they dont own the factory service manual and have no interest in buying one.
That is just not true. Any reputable shop has a subscription service that gives them access to the factory repair information, The shop I work for now uses three different services to make sure we have all the latest info because without it these days you are going to be fixing much. I know of no car company right now that still produces service manuals in print for modern cars. I have been turning wrenches for 34 years as a professional. I have donated a lot of this information to members of this forum and others when needed. In fact the diagram I posted to your thread is from one of these. Your welcome by the way.
 
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