Volvo: 1986 volvo 240DL electrical problems, freon 12, bentley service

Question
QUESTION: I know about the rotting insulation on the engine harness. I've got a problem with the A/C. It's been recently charged with 3 lbs. of freon 12, but the compressor clutch will not stay engaged. The mechanic at the import shop says the whole wiring systems have to be replaced, as it is shorting out.Where can I get a reliable harness replacement?
ANSWER: Ray,
I do not think that you can buy the wire harness. That will mean that one will have to be made. Most times only the wiring under the hood will need to be replaced. BTW 3 lbs of R12 is too much the proper amount is 2.9 lbs. 2.11 if you allow for freon in the charging hoses.

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QUESTION: What would cause the A/C clutch to kick in and out? Too much feron? Or a short in the wiring and /or switch relay? I am considering a updated engine harness replacement. I saw one on Ebay.Please tell me how to check some of these things I've got a Bentley service manual coming next week.
Thank you, Ray


Answer
Ray,
If the compressor cycles rapidly it usually means that the system is low on freon. The best thing to do is reclaim all the freon in the system, evacuate and recharge the proper amount, testing then to see how well it works. Then by watching the gauges you can see the pressures and what they are doing at idle and say 1500 RPM.