Have a 4.6L? Here's a problem I bet you all have...

[tclark228]

I have a 2005 EB 4.0 V6. Has all of the same symptoms but of course it isn't V8. power is getting to low pressure switch but compressor is not turning on. When I jump compressor off from batter it reads 15 on ac pressure gauge so it seems like this should be enough freon. I believe it is coming from problem with wiring between junction box and AC control module. Anyone know how to check the relay socket correctly? Any other ideas?

Thanks for the help

 

[Pontisteve]

I only have a 2003 EVTM manual, not an 05. And I can only assume an Eddie Bauer has the dual zone EATC climate control. But based on that limited info...

The AC clutch is grounded all the time, at G101 (left inner fender, somewhere near the front of the wheel well and up towards the hood). It gets power from the A/C clutch relay. When the relay is turned on, power from fuse F2.10 (central junction box, hot in start or run) travels through the AC clutch relay, thru a joint connector (for the A/C indicator diode), and to the AC clutch.

If you don't have 12v at the AC clutch, it's because the AC relay isn't getting powered up, or the fuse F2.10 (10 amp) is blown.

The relay's control side is powered up by fuse F1.37 (15 amp, located in battery junction box). Power runs from fuse F1.37 to the AC clutch relay (pin #1 ). So the control power is always hot when the key is on.

The relay's control side ground comes from the PCM sending a ground to the relay. The PCM has two inputs that it uses to decide whether or not to ground the AC relay. The first is the A/C clutch cycling pressure switch, and the second is the A/C high pressure switch. The high side switch needs to be at or below 260 PSI.

Both of these switch inputs are grounded all the time, and are normally closed. This means they always send ground to the PCM. Better said, the PCM sends 5v through a resistor to the switch. The switch grounds the wire, pulling the 5v down to ground through the resistor. When the PCM sees that the voltage on these inputs is 0 and not 5, it knows the switches are remaining ok (closed). The PCM then grounds the A/C clutch relay.

Check pin 2 on the AC clutch relay. That's the control side ground. Use a test light hooked to battery positive. If the PCM is grounding the switch, then your test light will light. If it doesn't light, then the PCM is either bad or it's not getting a ground on either pin 30 or pin 47 (the two AC switch inputs).

Hopefully your 05 is the same as the 03 I looked up.

 

[iivydriff]

Just put a new compressor on my wifes late 2002 mountaineer. Everything says its a 2003 but manufactured date was sept 2002. Compressor was locked up and someone rerouted the belt and added a pully and was running without the compressor in the belt loop. Anyhow i wanted to get the wife some air so I put a new compressor on. Added the right pully back on and put new belt on it. Charged up the system and no power to the A/c Plug. I checked everything couldnt figure out why didnt have power. I just cut the wires going to the plug and wired in two wires one to a switched spot in the fuse box and ran them to a toggle switch in teh dash. She has air now, but ill just bet the wire harness is cut at this spot by the oil filter and that is why i had no power. My temporary fix has worked great, but I intended on trying to get it fixed right. Because if I ever get a leak and low on freon and she kicks that compressor on it will smoke a compressor.

 

[FordNashMan]

Could starter be effected?

Hi guys, new to the forum and late to this thread but appreciate it very much. I have an 03 Eddie Baur 4.6 and had a couple issues with the starter not engaging. It's a new OEM starter with about 2k on it. I went out early in the AM and got the click of despair. After about 40 turn overs it fired right up. Only happened one other time about 3 weeks ago. I looked at the harness described here and lo and behold I'm down to the copper. Could this possibly be my problem?

 

[bookbinder]

Having just repaired my harness on my EX, and it exhibiting the same symptoms yours has, I would venture to say that yes this is your problem. Fairly simple to fix but I removed the tire and wheel seemed to make access a little easier. While there check your oil filter adaptor for any signs of oil leakage. Worth your trouble to inspect it while in there. Good luck to you and WELCOME.

 

[FordNashMan]

Having just repaired my harness on my EX, and it exhibiting the same symptoms yours has, I would venture to say that yes this is your problem. Fairly simple to fix but I removed the tire and wheel seemed to make access a little easier. While there check your oil filter adaptor for any signs of oil leakage. Worth your trouble to inspect it while in there. Good luck to you and WELCOME.

Thanks. I'm going to do this tonight as I am leaving for a trip tomorrow. I'll post my results. Also trying to figure out why my Advancetrac light keeps going off all of a sudden. I think I blew a seal where my cv half shaft goes into the transaxle. I'm leaking from there and my cv boot is broken. Hours of fun ahead of me.

 

[ICoull]

Why is it only a problem on the V8 and not the V6?

No plastic oil guard on the V6 oil filter location.

 

[D Hook]

Reminder to check.

 

[Mr Mumbles]

Well I'm sure glad I found this old thread as the AC in my '02 V8 Explorer Limited packed it in today leaving me with a long hot drive home. I had noticed earlier in the day the air coming out was cool and not as cold as it usually is so maybe the wire going to the compressor was hanging by a strand and finally broke. It's due for an oil change anyway so I'll check it while I'm under it tomorrow after I come back from another long and hot drive. At least I sure hope that's the problem as the fuse and relay are good and it seems to have lots of refrigerant in it when I pressed the low side valve and I don't really feel like swapping out the compressor.

 

[Mr Mumbles]

Well I'm sure glad I found this old thread as the AC in my '02 V8 Explorer Limited packed it in today leaving me with a long, hot drive home. I had noticed earlier in the day the air coming out was cool and not as cold as it usually is so maybe the wire going to the compressor was hanging by a strand and finally broke. It's due for an oil change anyway so I'll check it while I'm under it tomorrow after I come back from another long and hot drive. At least I sure hope that's the problem as the fuse and relay are good and it seems to have lots of refrigerant in it when I pressed the low side valve and I don't really feel like swapping out the compressor.

 

[Retci]

Well I'm sure glad I found this old thread as the AC in my '02 V8 Explorer Limited packed it in today leaving me with a long hot drive home. I had noticed earlier in the day the air coming out was cool and not as cold as it usually is so maybe the wire going to the compressor was hanging by a strand and finally broke. It's due for an oil change anyway so I'll check it while I'm under it tomorrow after I come back from another long and hot drive. At least I sure hope that's the problem as the fuse and relay are good and it seems to have lots of refrigerant in it when I pressed the low side valve and I don't really feel like swapping out the compressor.

I actually just fixed my problem. Be sure to also check the high side switch. That was the cause of mine actually. And because they changed the part, you'll have to change the switch as well as the pigtail to the switch. But that is easily bypassed by adding in a manual switch. The original part is on back order as far as I can fins sadly. But good luck!

 

[Mr Mumbles]

OK, this is getting interesting. I pulled the harness and found it easier to pull it straight up by the battery and drape it over the grill to work on it instead of pulling it out thru the left front wheel well. All wires in the harness were good except for a small worn area on the wire feeding the starter solenoid. There was no sign of the harness rubbing on the drain pan or anywhere else so it's possible this problem was fixed by the previous owner. The wire to the AC compressor ohmed out OK from the multi pin plug near the battery and I verified the compressor clutch by applying 12 volts to its pins. The wire also checks out from the multi pin to one of the relays terminals so I would say the compressor clutch circuit is OK.

Now this is where it gets interesting. After getting the vehicle back on the ground, I checked the refrigerant charge with my gauge set and it was good but the compressor wouldn't activate with the AC turned on and engine running. I had to jump it from the battery positive terminal to the relay terminal for it to work and make cold air inside the cabin. This told me the compressor wasn't getting the power signal from the relay. The fuse and relay under the hood were both replaced with new parts so the next step was to check both the high and low switches. Both switches ohm out OK but what I found was NO POWER to either the low or high side connectors with the engine on or off!

This has me stumped as I can't find a wiring diagram anywhere for the AC and need to know where the power source is for both switches and where the switches are in the circuit. The owners manual shows a diode in the distribution box has something to do with the AC as does a fuse in the main fuse box inside the cabin. One diode is for the PCM and the other is for the AC but why would diodes be in a DC power system? Doesn't make sense to me unless it's to prevent feedback. Anyway, would anyone be able to provide an AC wiring diagram for this '02 Ex Limited with the 4.6L or be able to suggest the next step? It seems as if a connection might have come undone somewhere. Thanks in advance and I'll be forever grateful!

 

[CallMeSyd]

Definitely gonna take a look at this on mine. Very interesting.

 

[Dean peulen]

I have a 2002 Eddie Bauer edition with the 4.6L V8 engine. I discovered a problem, thanks to a couple people on this forum, that I'd be willing to bet others are having or are going to have. Especially if you have an 02-05 Explorer with the V8 engine!

Recently, my A/C stopped working. I noticed that the clutch wasn't engaging on the compressor. I checked the coolant and noticed that it was still full. I checked all of the fuses and relays related to A/C. All were fine. I jumped the low pressure switch and still, nothing. Finally, after asking on this forum, somebody messaged me about a wire harness on the 4.6 that runs underneath the oil pan. This harness runs right under the aft side of the oil filter. If you look up right in front of the front differential, you can see where it is rubbing on the drip tray for the oil filter. Sure enough, it had chaffed all the way through the plastic shielding around the wires and had cut through the wire going to my A/C clutch. It was cutting through the wire going to my starter as well. Check it out. I'll bet anybody with the 4.6L is having the same problem. Mine only has 65,000 miles on it.

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There is no way you can really get in there to work on it, so, you'll have to disconnect it in a few places and pull it out through the left wheel well. You'll have to disconnect it from the A/C clutch. The best way is to get at it through the right wheel well. I didn't need to remove the wheel for this. You'll have to disconnect it from the starter. Best way is from underneath, obviously. Make sure you disconnect the battery first!!!! There is a metal bracket that comes next. I found it easier to just bend the metal that was holding the wire harness, than it was to take the nut out holding the bracket in. There is another bracket like it closer to the drivers side. Just bend that too. Then, there is a small wire coming out of the harness, that goes to some sort of sensor for the engine coolant. You'll need to disconnect that one as well. It's a PITA. After that, you can remove the front, left wheel and pull the wire harness out. You can see how it cut right through my compressor wire. The rubber shielding was the only thing holding it together.

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I'd guess that you all have this problem if you have the 4.6L. Crawl under there and check it out. If yours hasn't cut through yet, you might be able to stick something in there and stop it.

Thanks had a look. like lots of people who viewed your post exactly as you stated .Yet again thanks, would of been very hard to find that fault without your post. This car great to drive, but so many factory faults **** a good car. Never had any faith in my 2002 explorer to use it for real off roading. My jeep,Toyota and Mazda 4×4s out do my explorer in every way off road driving and reliability.