Electric fan and AC help needed. Phoenix is hot.

[stewie]

I recently bought a 96 XJ 2wd 4.0L to replace another xj I have thats been giving me too many problems. The prior owner of the "new" xj replaced the AC compressor when it failed with an idler pulley and looped the supply and discharge hoses together. I replaced the ac compressor, filter drier, expansion block, had the suction hose to the comp rebuilt, flushed the system and added 7.75 oz of PAG 100.

I took it to a shop to have the ac system vac and charged. The shop was unable to get the ac comp to engage on its on and was only able to charge the system by jumping the compressor wire to the battery. The compressor clutch engaged when they did so, and it blew out cold air. Also, during this time the electric fan never turned on.

Once home I replaced the relays for both the AC clutch and the aux fan as well as the 15 amp mini fuse that the owners manual describes as "a/c compressor clutch relay, radiator fan relay (4.0L eng.) EVAP/purge solenoid, low washer fluid level switch, park neutral position switch (auto trans.), backup light switch (manual trans.). The 30 amp maxi fuses for the radiator fan relay and the ac clutch relay both look good. The above is all in the PDC.

Now for the puzzling part- If I remove the relay for either the fan or the comp clutch then slightly reinsert it just right with the engine running and the ac on, then the component will turn on. Is this a wiring and or connector issue inside the PDC?

I know a lot of people say they need to get whatever fixed in a hurry, but I truly do- it was 113* here in Phoenix yesterday and my girlfriend is due to go into labor any day now and this Jeep is a lot easier for her to get into to go to the hospital in than my lifted XJ on 35s. So for mamma and baby I need to get it fixed.

Thanks in advance
stewie

 

[stewie]

With my DMM I have between 12.77 and 12.80V at the 15amp fuse listed above in the PDC. When reinserting the fuse I get the same momentary on (this time of both components) as before. I can not get them to stay on with the fuse in the same position, all the way in, nor with a jumper wire.

 

[stewie]

Also, I just swapped the sensor that screws into the Schrader valve on the filter drier with a known good unit out of my lifter 96 and still no result. Now I'm at a total loss here. I've also checked all the other fuses and they are good. Time for me to get out of the hot garage and wait for replies.

 

[8Mud]

What fuse number? This can really be helpful, as there is often various configurations and you can often match the fuse number and function (like power to the A/C relay) and figure out what wiring configuration you have.

The wiring diagram I have shows the A/C relay and the Aux fan relay on separate fuses. But they do share a splice. My 96 is actually half 95 and half 96.

You really have to be careful opening up the PDC, you can do more damage than good. You can fix one problem and loosen up connections just by stressing them and cause even more problems.

Best guess is you have a small bus that has come loose or shifted. Maybe a splice at the base of a relay (on a female spade connector socket) that is loose.

You can sometimes bend the very tip of the spade connector on a fuse or relay and get good contact on a loose female spade connector that has gotten hot and relaxed. Don't over do it, a 1/16" (or less) bend near the tip is enough and don't stress the relay spade connector and ruin the relay. You have to do it with a pair of needle nose pliers and with feeling. Not a solution, it is unlikely to last long, but may help with troubleshooting and figuring out exactly which socket is bad. You want to bend it just enough to get good contact, but not so much it won't go into the socket any more.

 

[stewie]

Thanks 8Mud. The fuse described above that is common between the two is listed as fuse #18 in the PDC and is a 15 amp mini fuse. It also lists two separate (one each) of 30 amp maxi type fuses #10 servicing AC clutch relay and #15 servicing the radiator fan relay. That info was taken from the 96 owners manual that was remarkably still in the jeep. And I see no reference to AC for the under dash fuse panel.

 

[8Mud]

I was going to post up some schematics, but my 96 (export) is different than yours. All I'd do is confuse matters some. I'll look around on the internut and see if I can't find a schematic or some excerpts that are relevant.

 

[8Mud]

Alldata may be an alternative, but I seriously don't know if it is worth it for the 96 or not? See if you can find an alldataDIY free trial or maybe a half off coupon. You are going to need some sort of reference if you ever hope to chase this down. I got lucky most of my early 96 is the 95 configuration and I can use those schematics. For some years Alldata is superior, for some, not so much.

Taking the PDC apart on a hunch gives me the willies just thinking about it. Not the most maintenance friendly setup in there. But doable if you are careful and slow. Some of mine I put back together with super glue, after chasing down a fried relay to starter solenoid wire. The wiring is a joke, way undersized for most components, especially the high amp stuff.

 

[stewie]

Yah, that's why I posted up here first. I don't want to tear into a PDC if I don't have too. There's too much chance of creating more problems than I fix even if the problem is there in the first place.

 

[KRAKER]

Come over and I'll fire up the alldata and we'll come up with a plan. Bring beer.

 

[8Mud]

I don't know how much I'd trust the owners manual and fuse location. I have two owners manuals and neither are (the same) or an exact copy of which and where the correct fuses are. Even the layout under the lid for the PDC is less than helpful or complete.

 

[KRAKER]

Looking at the diagrams I'm suspecting high resistance in the wiring to/from fuse 18.Possibly an ign switch issue. Where's my beer?