| Author |
Message |
Hans E. Hansen (4re_gt4)
Junior Member
Username: 4re_gt4
Post Number: 134
Registered: 4-2002
| | Posted on Sunday, September 01, 2002 - 3:40 pm: | |
Speaking of GT4 wiring here, GTB/GTS may not be the same. First, no relays. Power goes 1st thru both dash switches (temp & fan) in series, then to the two pressure switches (in series), then to compressor, then to ground. With the dash switches on, you should have 12V somewhere to those 2 pressure switches. Never really thought about this, but I wonder exactly how the compr clutch is grounded. Thru the compressor itself, and then to the mounting brackets? I suppose there is the possibility of a problem there. |
James Selevan (Jselevan)
Junior Member
Username: Jselevan
Post Number: 102
Registered: 6-2002
| | Posted on Sunday, September 01, 2002 - 12:49 pm: | |
Donny - I do not have a 308, but you might check the schematic to make sure that there is not a relay activated by the pressure switch. The pressure switch simply "grounds" the wire leading to it, which activates the relay. Thus, an open circuit between your compressor clutch and the pressure switch offers no information. Check the schematic for a relay. If present, identify and disconnect the load lead going to the compressor clutch. Apply voltage to this and see if the compressor clicks. This can be done without the engine running. It is unlikey that the compressor clutch would be directly energized through the pressure switch. More likely a relay. I assume, of course, that you examined all your fuses.
Jim S. |
Bruno (Originalsinner)
Member
Username: Originalsinner
Post Number: 477
Registered: 5-2002
| | Posted on Sunday, September 01, 2002 - 11:38 am: | |
I dont know what is wrong now. To answer your other question the system should hold a 30" vacuum overnite if everything is tight. |
Donny Bridges (Wildcatfans)
Junior Member
Username: Wildcatfans
Post Number: 84
Registered: 9-2001
| | Posted on Sunday, September 01, 2002 - 11:17 am: | |
Clutch checked out OK, 3.5 ohms. I am not getting voltage to the clutch so I checked continuity from the wire at the compressor to the pressure switch up front, next to the dryer (which I am assuming to be the high pressure switch). It was an open circuit, which means I either have a damaged wire, or there is some other switch that is open between them. My electrical manual shows there should be voltage at the low press. switch first, then the high pressure switch, then to the compressor. Is this the correct order? Is there anything between I'm missing?
Thanks |
Lawrence Coppari (Lawrence)
Junior Member
Username: Lawrence
Post Number: 230
Registered: 4-2002
| | Posted on Sunday, September 01, 2002 - 6:49 am: | |
My '87 328 has a high and low pressure switch built into one switch.
I hope the burning smell was not your clutch winding saying bye-bye. You can check this easily by disconnecting wire to compressor and checking the resistance across the clutch which is just an electromagnet. It should be 3-5 ohms. When the clutch fries, your resistance will drop at the clutch and you begin blowing fuses. |
Donny Bridges (Wildcatfans)
Junior Member
Username: Wildcatfans
Post Number: 83
Registered: 9-2001
| | Posted on Saturday, August 31, 2002 - 9:10 pm: | |
While trying to fill it today I ran into a problem. The compressor was running and the system was taking the 134. It was blowing cold air and the pressure was around 25 psi low side. I tapped a new can and begin adding refrigerant to get it to 45 psi or so when I smelled a burning smell then shut off the car. I waited a few minutes and started it up again to check pressures but the compressor never engaged. I think I added too much 134 so I began to let it out but no luck with the compressor. Checked voltages and I have 12 volts to the high pressure switch but nothing to the compressor. I plan to run a wire straight from the bat. tomorrow to verify the compressor clutch engages then start tracing back where I lose 12 volts. What is between the high pres. switch and the compressor? Low pressure switch maybe? Thanks for any advice.
Donny |
Bruno (Originalsinner)
Member
Username: Originalsinner
Post Number: 474
Registered: 5-2002
| | Posted on Saturday, August 31, 2002 - 8:55 pm: | |
If you cant pull to 30" you got a leak. |
Donny Bridges (Wildcatfans)
Junior Member
Username: Wildcatfans
Post Number: 82
Registered: 9-2001
| | Posted on Friday, August 30, 2002 - 11:43 pm: | |
I'm working really hard to have the A/C fixed by Sunday. I can't image what it would be like to get caught out in a rain storm, and have to put the top on without A/C in this Louisiana heat and humidity. Thanks anyway for the offer. See ya Sunday. |
Kelly (Tifosi1)
Member
Username: Tifosi1
Post Number: 368
Registered: 2-2002
| | Posted on Friday, August 30, 2002 - 10:59 pm: | |
Donny I got the leak tool from Autozone. I know it's a long way, but do you want to come by the house Sunday before dinner and hook it up and see???
I'm going to do the leak thing to mine tommorrow. Let me know casue I want to get my $90 baack on my credit card.
THX
Kelly |
Donny Bridges (Wildcatfans)
Junior Member
Username: Wildcatfans
Post Number: 81
Registered: 9-2001
| | Posted on Friday, August 30, 2002 - 10:23 pm: | |
I have a slow leak on my A/C system (84 308) that I am attempting to fix. I think the leak is the quick connect I installed on the compressor low side fitting because I see some oil residue on the cap. I replaced it with another fitting today and pumped it down with a vacuum pump I rented from Auto Zone ($300 deposit but I get it all back when I return it) to 28 mmHg. 3 Hours have past and the gauge now reads 26 mmHg. I will leave the gauges hooked up tonight and check tomorrow morning, but my question is, is any fluctuation in the vacuum reading acceptable? Could it leak slightly under a vacuum and be OK under pressure? Will temperature affect the reading any?
If the readings don't change to much I plan to put in some of this stop leak/red dye I bought today before I begin adding the R134. Hopefully if there is a leak it'll help me find it.
Thanks for any suggestions or recommendations. |