kpeters59

My Test Light did illuminate during Engine Run / AC On at the Cycling Switch Light Green wire.

Shorting those Pins together seemed to have no effect.

There was Power at the 2 left pins of the AC Relay in the Undehood Fuse Block.

I was not able to get continuity to ground at any of the pins for the Relay.

I'd swapped the Fuel Pump and AC relays before. They both must be good.

Thanks,

-Kyle

branden Clark

If you short terminals 87 and 30 and the clutch kicks on you can verify that at least that part of the circuit is good.

branden Clark

Bottom left and top right should activate the clutch, if you look under the relay the pins are numbered

kpeters59

Yeah...that did work. There's 12v there at Key Off...

So, pulling the bottom right (in that photo above, pin 85) to ground ought to make the AC come on too then, right?

The ECM is supposed to be pulling that to ground?

So, now to determine why it's not?

It might be expecting Pressure Switches that don't exist?

I broke down and texted 'him'. He'd made a comment while he had it that he'd figured out why my AC didn't work. I noted it, but didn't get any more information. Apparently it was important. It had been working decently 'til that point.

Thanks,

-Kyle

ryeguy2006a

iTrader: (27)

Another thing you may want to consider is that if you were swapping harnesses, there were differences between the years. I think that 95-96 were different from 97-98.

kpeters59

Yeah...I'm not sure exactly what year it was.

I was roaming around the Junk Yard looking for something else and noticed how unmolested the Harness looked on that 4-door OBS.

I couldn't let it go and spent about 2 unscheduled hours very carefully extracting it from the Engine Bay.

The connections on the back of the block were particularly tough. I even completely removed the Bulkhead Connector and the Fuse Block. It was even a 4x4, too!

Once 'he' got it, I expect that it should have all been taken care of properly. What was I thinking?

Thanks,

-KP

kpeters59

The Haynes Manual has an AC Page for '94 and earlier and '95 and later.

-Kyle

branden Clark

branden Clark

Now that I have my 10 posts it let me post the diagram

kpeters59

Thanks!
That is a better Diagram. The color is helpful. And the 'breakout location' info is helpful, too.

Any chance you've got a Higher Resolution version? Some of the Breakouts I can't really read from over here...

Thanks,

-Kyle

branden Clark

Ok to add to the confusion The 98 truck i said earlier matches what you have for colors at the A/C accumulator, that truck is a diesel. I just had time to go out back and look at my 98 2500 5.7 gas and it matches the diagram I posted above and has the BLK/wht and the Dk. GREEN wires at the cycling switch.

branden Clark

That is the best I have. I had to open it in gallery to zoom further than chrome to read the comments

kpeters59

Yeah, well add in the Motor Swap, the multiple hands inside and 23 years of me owning it and no wonder it's not working.

Thanks,

-Kyle

branden Clark

Check to see if you have continuity between C2-43 (red) and the 85 pin on the A/C relay

kpeters59

Yes there is...

Thanks,

-Kyle

branden Clark

What about C2-17 and one of the wires going to the switch on the accumulator?

kpeters59

No...but I wouldn't expect them to. They're different colors.





Thanks,

-Kyle

branden Clark

did he put it on c2-55?

kpeters59

Apparently not...



Thanks,

-Kyle

branden Clark

If you can find where the cycling switch wire is or get it to the PCM I can make a diagram later showing how to get this to work with what you have.