A/C voltage help (1 Viewer)

[James91Mr2]

Hey guys new FJ owner and forums member here. I just recently purchased an 85 FJ60 and have been tinkering with it here and there. Noticed the A/C clutch on the compressor won't engage. It's not getting voltage when you press the a/c button on the dash. The button lights up and the fuse is good in the dashboard. If I hotwire the compressor to the battery to give it 12v the clutch works fine. Is there a relay or something hidden that could be stopping the voltage?

Thanks in advance!

 

[Elbert]

When you hot wire the compressor does the a/c get cold? Low freon charge will keep the compressor from engaging.

 

[James91Mr2]

Yes it does. Was out of freon but I charged it back up. Problem is when I press the A/C on the dash it doesn't send voltage to the compressor to engage the clutch.

 

[hank14]

Is your a/c idle up solenoid working? (Do the RPMs increase on the engine?) There is an A/C amplifier under the dash near the passenger side that may need adjusting. Search A/C amplifier for more info.

 

[James91Mr2]

I don't think the idle up solenoid is working. Basically only thing that happens when you hit the a/c button on the dash is it lights up! Thanks for the a/c amplifier info. I'll look for it today.

 

[djawahir]

First off, we don't believe you own a 60...because you haven't posted any pics of it!!!!

BTW, Welcome to Mud!

 

[James91Mr2]

Tada...

 

[James91Mr2]

So as far as diagnostics go... is there a way to test the a/c amplifier? I've confirmed the switch works and sends voltage to it. Dunno if it sends info the idle up guy or not. Do I just replace the amplifier and work from there?

 

[djawahir]

The amplifier isn't cheap. You may want to test what you have. The first thing I'd check is the little blue dial on the top of the a/c amplifier. Turn the knob all the way clockwise and all the way counter clockwise. (i say this because I can't remember which way kicks off the compressor at lower rpms.)

Then try turning the knob both directions while idling at over 1400 rpm or so and see if the compressor turns on.

I know i have a manual somewhere...I'm just too lazy to grab it right now. Maybe someone else can chime in with easy way to do a basic operational check on the a/c amplifier.