Adding manual switch for ac compressor that wont work

volvoqueen89 · Post by **volvoqueen89** » 18 May 2016, 15:26

My friend bought a car that had a switch added to manually turn on and off his ac compressor because that is how it worked i guess. I cannot get my own compressor to turn on that i just bought. The clutch looks to be fine. I saw somewhere about creating a momentary connection to the terminal of the battery to compressor terminal and i wasn't sure if thats an accurate way to check if it works correctly or not.

If it does work which relay or fuse ect am i connecting the wire to for it or do you know exactly what to put it to. The wiring in the original car is a diff model so i dont think it will work the same. Also ive tried changing the relay and adding frion both did nothing to change the status.

I usually do my own work on my cars and am trying to continue that here. Thanks for reading, let me know if you have any suggestions please since my friend is now refusing to help.

lummert · Post by **lummert** » 18 May 2016, 23:15

There are a few things that can cause the compressor clutch not to engage. The climate control system is a good place to start your research.

93Regina · Post by **93Regina** » 19 May 2016, 07:42

volvoqueen89 wrote:compressor terminal

Testing starts with a test light...at the compressor's input wire...does it have voltage?

Do remember, there maybe a time-delay before voltage is sent to compressor

Post by **abscate** » 22 May 2016, 06:45

That's a really risky setup. AC compressors are designed to cycle and also turn off either low pressure, high pressure, or icing. Forcing the compressor on will bite you eventually

volvoqueen89 · Post by **volvoqueen89** » 23 May 2016, 19:26

Ok, not sure my issue then :/

volvoqueen89 · Post by **volvoqueen89** » 07 Jun 2016, 20:40

OOk update the compressor works and everything. Theres no frion so it wasnt cold. But the way it was checked we saw the compressor itself was getting hot? So Im trying to figure out the whole diagram and line of the system. As far as the compressor starts here and lead to this and then this and ends up here. I need to trace back everything and check it out. But i cant fins what i need? Anyone have this diagram?

woodchopper · Post by **woodchopper** » 13 Jun 2016, 23:32

I had a toggle switch hooked up a few years ago to force the compressor on. Jumpering the terminals on the relay is how you get the compressor to start. First there has to be enough refrigerant (Freon) to pressurize the system and activate the compressor. If the compressor turns then there is Freon. However what you may be seeing is the compressor pulley turning but the clutch is not engaging. I tried changing the relay but it still wouldn't kick in. I took it to a Volvo dealer and they got it to work but then it would keep shutting off. The problem was the compressor clutch gap was too wide and it would shut off after it got warm. There is a quick fix for that using plastic bread bag clips, but according to a video I watched it is acutally quite easy to take the clutch off and make the proper adjustment. I eventually got another compressor put on at a Volvo wreckers and it solved all the problems.

volvoqueen89 · Post by **volvoqueen89** » 21 Jun 2016, 20:43

Thank you, i just am wondering now how to check any kind of switches there is to it. Like i need to check the buttons and stuff because this mechanic said its electrical at this point and i cant afford to get that looked at now too.

Post by **abscate** » 27 Jun 2016, 08:14

You need to know the history and how long the Freon charge lasts. If it sat a long time near empty, wait until you have about $1000 bucks in the bank to fix the AC - otherwise you end up blowing up the compressor and pushing metal throughout your system - which gets really expensive.

AC is one of the things that can kill an old car with careless DIY. The 'charge your AC' cans sold at department stores cause untold amounts of pain.