phorge
New Member
- Joined
- March 3, 2003
- Messages
- 1
- Reaction score
- 0
- City, State
- Farmington, MO
- Year, Model & Trim Level
- 99 Limited
1999 Ford Explorer Limited | 5.0L V8 | Electronic Climate Control
The short version:
Every time I put the Explorer in gear, I blow the 10a A/C Relay fuse under the hood.
The long version (or, how I got to this point):
I went to use my A/C on the first warm day we had this summer and it didn’t work. My brother has a full set of A/C tools and gauges, so I had him take a look at it (I assumed it was low on Freon). He connected the low and high pressure gauges, but couldn’t get a valid reading because the clutch was not engaging on the compressor. He discovered that the A/C relay was not clicking and that I likely had a bad relay. I went to AutoZone and bought a new relay and installed it and it still wouldn’t engage. I then tested both the low pressure and high pressure switch leads for 12v and was receiving proper voltage. I checked all fuses under the hood and in the vehicle, all fine. The next thing I did was check the 2 pin plug on the compressor that engages the clutch. I was getting 12v on one pin (for a while, this will change later), but no ground on the other pin. I made a 12v and GND jumper wire from the battery straight to the compressor to see if the compressor or clutch was bad and it engaged and ran with no issues. We then attached the A/C gauges and started the vehicle again with the compressor running straight off the battery and new ground… all pressures read ok (I don’t remember the readings, just that my brother said they were fine). I decide that my problem is a lack of ground and set out to fix that. I read that in the wiring harness there is a diode in line with the ground wire that can go bad. I cut up the harness to get to the diode and solder in a new one from RadioShack… still no dice. No ground on the 2nd pin of the compressor and the clutch still won’t engage (without jumpering it to ground anyway). I tried 2 diodes installed in both polarities and no dice. I eventually give up and decide to just run a new ground wire from the frame to the 2nd pin of the compressor / clutch connector with no diode. I get done with this and now have a proper ground in the plug and everything works… until I go to drive it. Very, very long story short, when I tested the pressure switches, I didn’t get the high pressure switch fully reconnected and it was stopping power from going anywhere past it. I tried and tried to get the connector back on the high pressure switch, but it just wouldn’t go and I was afraid I was going to break the tubing it was mounted on if I pressed any harder. I decided screw it, and jumpered the high pressure switch with a small piece of copper wire and then covered it with electrical tape. Success! I have A/C… until I drive home. By this point, I am frustrated beyond belief chasing this electrical gremlin and really just don’t have the time to mess with it. A few weeks go by with 90+ degree heat and 80+% humidity and it’s time to try and fix this thing again. I get out my multi-meter and check for ground at the compressor plug… still there. Check for 12v at the compressor plug… no dice. I checked the low and high pressure switches for 12v… all there. The 10a A/C Relay fuse under the hood, blown. Aha! Quick run to AutoZone for a pack of 10a mini fuses and we’re in business. I install one while still in the parking lot, clutch engages and A/C is blowing cold air… sweet! I drive home, and no more cold air. I check the fuse and it’s blown again. I replace it and its fine again. I turn the A/C off and on multiple times as well as the engine… fuse never blows. Next day I drive to work, and have no cold air. Get to work and check the fuse, blown again. I replace it before I drive home; once again… no cold air and another blown fuse. This morning I install a new fuse and start the vehicle. I put the A/C on max, clutch engages, and A/C is cold as it can be. I let the vehicle run in the garage for a good 5 minutes and everything is fine. I set the ebrake and then put the vehicle in gear and the clutch stops and the fuse has blown. Any ideas? This is driving me crazy.
The short version:
Every time I put the Explorer in gear, I blow the 10a A/C Relay fuse under the hood.
The long version (or, how I got to this point):
I went to use my A/C on the first warm day we had this summer and it didn’t work. My brother has a full set of A/C tools and gauges, so I had him take a look at it (I assumed it was low on Freon). He connected the low and high pressure gauges, but couldn’t get a valid reading because the clutch was not engaging on the compressor. He discovered that the A/C relay was not clicking and that I likely had a bad relay. I went to AutoZone and bought a new relay and installed it and it still wouldn’t engage. I then tested both the low pressure and high pressure switch leads for 12v and was receiving proper voltage. I checked all fuses under the hood and in the vehicle, all fine. The next thing I did was check the 2 pin plug on the compressor that engages the clutch. I was getting 12v on one pin (for a while, this will change later), but no ground on the other pin. I made a 12v and GND jumper wire from the battery straight to the compressor to see if the compressor or clutch was bad and it engaged and ran with no issues. We then attached the A/C gauges and started the vehicle again with the compressor running straight off the battery and new ground… all pressures read ok (I don’t remember the readings, just that my brother said they were fine). I decide that my problem is a lack of ground and set out to fix that. I read that in the wiring harness there is a diode in line with the ground wire that can go bad. I cut up the harness to get to the diode and solder in a new one from RadioShack… still no dice. No ground on the 2nd pin of the compressor and the clutch still won’t engage (without jumpering it to ground anyway). I tried 2 diodes installed in both polarities and no dice. I eventually give up and decide to just run a new ground wire from the frame to the 2nd pin of the compressor / clutch connector with no diode. I get done with this and now have a proper ground in the plug and everything works… until I go to drive it. Very, very long story short, when I tested the pressure switches, I didn’t get the high pressure switch fully reconnected and it was stopping power from going anywhere past it. I tried and tried to get the connector back on the high pressure switch, but it just wouldn’t go and I was afraid I was going to break the tubing it was mounted on if I pressed any harder. I decided screw it, and jumpered the high pressure switch with a small piece of copper wire and then covered it with electrical tape. Success! I have A/C… until I drive home. By this point, I am frustrated beyond belief chasing this electrical gremlin and really just don’t have the time to mess with it. A few weeks go by with 90+ degree heat and 80+% humidity and it’s time to try and fix this thing again. I get out my multi-meter and check for ground at the compressor plug… still there. Check for 12v at the compressor plug… no dice. I checked the low and high pressure switches for 12v… all there. The 10a A/C Relay fuse under the hood, blown. Aha! Quick run to AutoZone for a pack of 10a mini fuses and we’re in business. I install one while still in the parking lot, clutch engages and A/C is blowing cold air… sweet! I drive home, and no more cold air. I check the fuse and it’s blown again. I replace it and its fine again. I turn the A/C off and on multiple times as well as the engine… fuse never blows. Next day I drive to work, and have no cold air. Get to work and check the fuse, blown again. I replace it before I drive home; once again… no cold air and another blown fuse. This morning I install a new fuse and start the vehicle. I put the A/C on max, clutch engages, and A/C is cold as it can be. I let the vehicle run in the garage for a good 5 minutes and everything is fine. I set the ebrake and then put the vehicle in gear and the clutch stops and the fuse has blown. Any ideas? This is driving me crazy.
