1990 AC compresser not kicking in

Jeepermeo2 · 07-23-2012, 08:02 AM

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 · 07-23-2012, 10:32 AM

Quote:

Originally Posted by 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.

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 · 07-23-2012, 05:43 PM

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 · 07-23-2012, 06:36 PM

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 · 07-24-2012, 07:55 AM

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 · 07-24-2012, 09:54 AM

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 · 07-24-2012, 07:37 PM

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 · 07-24-2012, 09:33 PM

Quote:

Originally Posted by 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

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

Jeepermeo2 · 07-30-2012, 10:46 PM

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

07-23-2012, 08:02 AM	#1
Jeepermeo2 Join Date: Dec 2008 Location: Middletown, OH Posts: 8	1990 AC compresser not kicking in 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.

07-23-2012, 06:36 PM	#4
WrenchMonkey Mechanical Animal - CORE Member - - Moderator - Join Date: Feb 2008 Location: Beechmont Posts: 1,883	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 __________________ DIRTY DEEDS, DONE DIRT CHEAP Whatever doesn't kill you makes you stranger

07-24-2012, 09:54 AM	#6
cincygman Join Date: Nov 2008 Location: Pleasant Run Farms (near Fairfield) Posts: 378	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 __________________ Romans 7-8

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07-23-2012, 05:43 PM	#3
Jeepermeo2 Join Date: Dec 2008 Location: Middletown, OH Posts: 8	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.

07-24-2012, 07:55 AM	#5
Jeepermeo2 Join Date: Dec 2008 Location: Middletown, OH Posts: 8	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.

07-24-2012, 07:37 PM	#7
Jeepermeo2 Join Date: Dec 2008 Location: Middletown, OH Posts: 8	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

07-30-2012, 10:46 PM	#9
Jeepermeo2 Join Date: Dec 2008 Location: Middletown, OH Posts: 8	Thanks to all who replied. Problem ended up being a bad relay. Changed it out and now it works fine! Again Thanks Mitch