Hi Guys,

I've found a few discussions related to a lack of current at the A/C compressor but I'm still stuck trying to diagnose the problem with my Gen I.

1990 Montero LS 4D

I had the A/C recharged a few weeks ago and everything seemed to work fine. A week later I turned it on for the first time while driving on a hot day and got nothing. I am not getting any current at the compressor or the fan and can't figure out where the problem is. The blower seems to be getting current and both fuses behind the glove box are good and have current flowing through them. I thought it might be the push-button switch so I replaced it and the situation is the same.

I think that the problem is between the battery and the switch and not between the switch and the compressor. Please correct me here if I'm wrong. In order for the switch to work the blower must be on. On the switch itself, current enters via a green wire with a white stripe and heads out to the compressor via a black wire with a white stripe. As far as I can tell, the green wire has no current and I have checked it at numerous spots under the left side of the dash.

So here are a few questions:

1. Am I misunderstanding the role of the wiring at the switch and the need for current in green wire with the white stripe?

2. I though it could be an AC Compressor relay that is bad and I found one to order online. But where is it located on the truck?

3. Could this be a problem with the dual pressure switch? Where is that located?

4. There is a switch that is connected to my A/C vacuum hoses. What is this? I get current on one side of it but only very faint current on the other side. I can replace it but I don't know what it's called.

5. Does anyone have a diagram for this that includes the colors of the wires?


I've gotta get this fixed; it's HOT here in DC! Plus I'm driving back to LA in two weeks.

Thanks for your help,

Matt