1990 AC compresser not kicking in

[Jeepermeo2]

I bought a 1990 Cherokee and was told the AC did not work. I put a can of R134 in (it has been converted) and hot wired the compressor and it cooled great. Is there a fuse or relay that might be causing the compressor to not engage? I don't have a owner manual.

[biggin69]

I bought a 1990 Cherokee and was told the AC did not work. I put a can of R134 in (it has been converted) and hot wired the compressor and it cooled great. Is there a fuse or relay that might be causing the compressor to not engage? I don't have a owner manual.

Yes Sir! I have a 92 model and there is a fuse under the dash with the rest of the fuses and another under the hood.

[Jeepermeo2]

Thanks
I will check all the fuses under the dash but I only see relays under the hood on the passengers side with no marking.

[WrenchMonkey]

1990 is Renix, 1992 would be H/O, so there will be some discrepencies there...

I know there's a pressure switch that will keep the compressor from coming on if the coolant level is low. Are you sure your one can was enough to fill it all the way? No idea myself...

Robert

[Jeepermeo2]

I did not use a gauge but it is very cold when I hot wired it.
I tried it last night and it is still blowing cold.

[cincygman]

you have to put gauges on it. no way that one can enough if system was low. the low pressure cut out switch is on the big line on the passenger side. you can test it by unplugging it and put a jumper wire in it, the plug. that will tell you if its just a fuse or still maybe low on charge

[Jeepermeo2]

I put a jumper wire in the plug and the compressor did not engage.
So is it a fuse or still maybe low on charge?
I'm thinking fuse or bad wire. Will check the fuses with a meter this time.:o
Thanks

[biggin69]

I put a jumper wire in the plug and the compressor did not engage.
So is it a fuse or still maybe low on charge?
I'm thinking fuse or bad wire. Will check the fuses with a meter this time.:o
Thanks

Most likely a fuse. Check them before you dig too far.

[Jeepermeo2]

Thanks to all who replied.
Problem ended up being a bad relay.
Changed it out and now it works fine!
Again Thanks Mitch