Rear air problem

[HUMMERcustoms.com/TAZ]

It will be Ok to pull fuse and run just to backup te advice given. If air is lost then You will be riding on the stops on rear of course with quite rough ride.

I have not looked at 03 but You chould have air holding tank on p;atform that pump is mounted on. They are plastic lines and possibly have a hole or tank could have a hole (not likely) unless exhaust got against it. Could be a bad connection on lines to pump.

If You are concerned about pulling fuse just in case something else may be controlled by it You can crawl under the back and look up to see air pump/tank unit and will see a plug running to it from a wiring harness. You can disconnect there and only issolate that setup of pump and tank. The unit is qute heavy but You can unbolt I think the forward bolts and lossen the back bolts so it will hang down and You could turn pump on and possble hear leak or feel it with hands.

I agree the relay would be the simplest to try first.

If I left something unclear do not hesitate to ask me to clarify.

TAZ

[AUHUMMER]

Found the relay. Its mounted on a bracket on the firewall about 4 inches below where the steering exits the firewall. I searched online and the forum but can't find a part number for the relay...anybody have that #?

I really HATE doing any electrical work on a car!!! Anything else is fair game but back in '74 I installed a CB radio in my first car, a 1974 Trans Am, and for 2 weeks after that, every time I stepped on the brakes all the interior lights would come on. But, if I can get the part, this shouldn't be a problem (famous last words). Thanks again for the help. And TAZ, thanks for the advice---I'm just really hoping its not a case of tracking and trial and error.

[MarineHawk]

Originally Posted by AUHUMMER

... back in '74 I installed a CB radio in my first car, a 1974 Trans Am, and for 2 weeks after that, every time I stepped on the brakes all the interior lights would come on.

LOL.

[HUMTECH]

Don't have the part# but any GM dealer should be able to get you one. Ask for A ECAS relay(electronically controlled air suspension).

[AUHUMMER]

HUMTECH---you da man!! Got the relay from the GMC dealer 25 miles away--local didn't have it. Got home and it wouldn't fit. I had asked for a ECAS relay for '03 Hummer H2. This time I followed my own long standing rule---take the part with you-- and they swapped it out. He looked it up again, and showed me where his data base had it wrong. Anyway, the correct part # is 15319851. I installed relay, put the fuse back in and ...bingo...we have air. I think it had to readjust itself or something because initially the compressor did not turn on. It didn't air up to normal ride height until I drove to work. Everything appears to be back to normal. Thanks again for the advice from all you guys---I was really dreading troubleshooting all that plumbing.

[timgco]

BY any chance do you have your air hose screwed on? THat causes issues also.

[AUHUMMER]

No, air hose is not screwed on. Guess it was just the relay.

[CBR_Raven]

Originally Posted by AUHUMMER

HUMTECH---you da man!! Got the relay from the GMC dealer 25 miles away--local didn't have it. Got home and it wouldn't fit. I had asked for a ECAS relay for '03 Hummer H2. This time I followed my own long standing rule---take the part with you-- and they swapped it out. He looked it up again, and showed me where his data base had it wrong. Anyway, the correct part # is 15319851. I installed relay, put the fuse back in and ...bingo...we have air. I think it had to readjust itself or something because initially the compressor did not turn on. It didn't air up to normal ride height until I drove to work. Everything appears to be back to normal. Thanks again for the advice from all you guys---I was really dreading troubleshooting all that plumbing.

thanks for the part #...i changed the relay out on mine as well. it was only a 10 minute job