i will check the voltage tomorrow...
no power to AC compressor ?
Thread Starter
Instructor
Joined: Sep 2003
Posts: 217
Likes: 0
From: Roskilde, Denmark
no power to AC compressor ?
Hi
I just got my AC system charged with R134a. The system have been offline all the time i have owened the car.
I bougth a sanden compressor from Erik, and a condenser for another guy. New dryfilter from the local dealer.. The system is holding pressure, and everything works perfect if i shortcut the AC clutch..
My problem is:
The Clutch will not engage if i use the original wire.. If i disconnect the wire and test the voltage, it reads 10,8 volt... if i connect it to the compressor again it suddenly reads 0 volt.
What is going on ? is there not enough voltage to engage the AC clutch ? or do i have a defekt relay ?
Hope you guys can help me
Mads
BTW the car is a 1977 Euro 5 speed
I just got my AC system charged with R134a. The system have been offline all the time i have owened the car.
I bougth a sanden compressor from Erik, and a condenser for another guy. New dryfilter from the local dealer.. The system is holding pressure, and everything works perfect if i shortcut the AC clutch..
My problem is:
The Clutch will not engage if i use the original wire.. If i disconnect the wire and test the voltage, it reads 10,8 volt... if i connect it to the compressor again it suddenly reads 0 volt.
What is going on ? is there not enough voltage to engage the AC clutch ? or do i have a defekt relay ?
Hope you guys can help me
Mads
BTW the car is a 1977 Euro 5 speed
Rennlist Member
Joined: Jan 2004
Posts: 12,620
Likes: 8
From: Boulder Creek, CA
I just went through this. Thread here. Trace the circuit back until you figure out where the voltage is dropping. Do you have the current flow diagram? If not, I posted a big enough piece of the diagram on that thread that you should be able to troubleshoot further. If you're getting low voltage at J2 then it could be a problem with the control head or the freeze switch. If the voltage drop is between Q2 and the compressor it could be the low pressure switch. If you're getting low voltage at J1 then it could be fuse 17 or the blower relay. If the voltage is fine up till Q2 then you could have a bad speed relay. Or you could have PO-hacked wiring as I did. I'll have an update posted to my site in the next day or two, detailing how I corrected the problem.
HTH
HTH
Thread Starter
Instructor
Joined: Sep 2003
Posts: 217
Likes: 0
From: Roskilde, Denmark
It works perfect if i apply 12v to the Clutch...
Erik. How do i check the Pressure sensor ?
The relay clicks when i turn the AC on.. How can i check if there is something wrong with the relay ?
Mads
Erik. How do i check the Pressure sensor ?
The relay clicks when i turn the AC on.. How can i check if there is something wrong with the relay ?
Mads
Trending Topics
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
9 Features and Characteristics That Only Porsche People Understand
Verdad Gallardo
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way
Joe Kucinski
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)
Verdad Gallardo
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner
Joe Kucinski
This Builder Is Turning Heads With Its Slantnose 911 Creation
Verdad Gallardo
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Verdad Gallardo
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
Rennlist Member
Joined: Jan 2004
Posts: 12,620
Likes: 8
From: Boulder Creek, CA
Originally posted by Ed MD
Go to the Nichols site and look up DrBob's notes on the work-p, I just did it for my 88. I used the radio shack relay, works great Ed M
88 S4,
85S
Go to the Nichols site and look up DrBob's notes on the work-p, I just did it for my 88. I used the radio shack relay, works great Ed M
88 S4,
85S
Three Wheelin'
Joined: Oct 2003
Posts: 1,315
Likes: 0
From: Sacramento, CA
Dave et al,
The heads are supposed to be different on the early cars. They don't have the relay.
I thought I had the dreaded relay issue on my S4. Turned out to be that the PO unplugged the a/c button when installing the stereo. Good luck and hopefully you will be chillin soon. I sent Dr. Bob a pm with some questions when I was having my issue and he replied real quick with some excellent strategies. He is very knowlegable and is also a nice guy. If you get frustrated, drop him a line.
Regards,
The heads are supposed to be different on the early cars. They don't have the relay.
I thought I had the dreaded relay issue on my S4. Turned out to be that the PO unplugged the a/c button when installing the stereo. Good luck and hopefully you will be chillin soon. I sent Dr. Bob a pm with some questions when I was having my issue and he replied real quick with some excellent strategies. He is very knowlegable and is also a nice guy. If you get frustrated, drop him a line.
Regards,
Burning Brakes
Joined: Apr 2002
Posts: 881
Likes: 0
From: Denmark
Mads,
The pressure sensor is a simple on/off switch securing that the compressor is not running if your cooling media is too low
So simply check the switchs, is it on or off - It shall be on (The 2 wires coming out of the switch)
Regards from Erik in Denmark
The pressure sensor is a simple on/off switch securing that the compressor is not running if your cooling media is too low
So simply check the switchs, is it on or off - It shall be on (The 2 wires coming out of the switch)
Regards from Erik in Denmark
