ARB compressor relay bad?

Trying to finish up installing a single ARB compressor and think I may have a bad relay. With the dash switch in the on position I get ~ 2.5 volts on the trigger wire at the relay, but the compressor will not run. If I bypass the relay with a short jumper the compressor fires right up. I think the relay is bad, but I can't find anywhere what the trigger voltage for it should be.

 

Is the compressor used? We've noted similar problems in the dual compressor as the relays aren't sealed and over time get dirt inside. Once it gets a bit damp they go to crap. I have a dual ARB in my Jeep and the compressor is installed under the seat and so far (six years) I've dodged the problem. In our 4500 class KOH car the compressor was under the hood and they both filled with dirt. Replacing the relay is obviously a good idea, carrying a spare is another good one. Smearing some RTV around the base of the relay may improve longevity as well.

 

Everything is brand spanking new.

 

have you called ARB USA yet? They had great customer service when I needed help. My compressor arrived without a filter, called them up and they shipped me two.

 

Not yet. I just did the wiring yesterday and this morning. I will be calling tomorrow if i don't have an answer before then.

 

You should have 12 volts at the relay with the switch on, not 2.5. Have you double checked your wiring?

 

This.

 

I did but guess I will have to do it again.
I have 2.75 volts on the red/green wire that is soldered to a 12 volt wire behind the heat control panel. This is the wire with the diode in it, so maybe I need to test that as well.
Thanks

 

Take a wire from the battery and touch it to the trigger contact on the relay. If that works then grab your switch power using an add a fuse in the fuse box behind the cubby.

 

So you tapped into a red/green wire behind the dash? Do you know what that goes to? I don't... Does the voltage change with the ignition on?

 

I'm wondering if he tapped a servo wire as I think about this...

Edit: for the blend doors... Hot/cold. Face/feet/defrost... Hope that makes sense.

 

So I sort of misquoted and sort of didn't explain real well. The wire is actually red/yellow and is the wire included with the ARB wiring harness. It is the wire that has a diode and runs from 12 volts switched to the back of the ARB dash switch. It is spliced into I think it was white/black that is plugged into a 10 position white connector that plugs into the back of the heat and a/c panel pretty much behind the fan switch.
When I got home from work, I disconnected that wire from the back of the ARB switch and ran a jumper straight from the battery to the switch and the relay energized and the compressor turned on. So my next step is to test the diode (forgot to bring a good Fluke meter home from work) and figure out if the diode is either bad or even maybe just in backwards. Either way I'm going to just run that red/yellow wire up to the fuse panel under the driver's side of the dash and tap into one of those fuses.

 

No drawing/wiring diagram?
I'm losing it... What's the diode supposed to do?
And the switch. Any info on that? Lighted/ 3,4 terminals?

 

White with a black stripe is always ground on these Tacos. That seems like it could definitely be a problem.

 

Here's the schematic. There's a lot going on there.

 

Not sure what the diode is there for as they have several uses. The switch is the standard ARB rocker switch. Here's a pic of the back of it and the individual pin functions.

 

Didn't realize that. It was definitely a white wire, but I certainly would not swear to the strip color. I'll have to double check it when I get a chance later this week to tear everything back apart.

 

So, I'm curious what led you to believe that you should tap into a white/???? wire for key switched power?

 

Probing around with a multimeter. And it was close to the location of the switch.

 

Does that switch have separate lights for dash lighting and being turned on?
If that's the case, tap both dash lighting wires and run another ground for the on light.