It's been a while since I toyed with it but it is nearly identical to the OEM unit but bigger. The wiring hooks up a little different too. IIRC, there are two wires for power and ground, and two more for a solenoid that opens and closes an air valve. These units were meant to run in a system with no reservoir. That means, they did the job of not only inflating but also deflating the shocks as well. So, my understanding of the system is that when the shocks need inflating, the compressor turns on and does just that. When the shocks need deflating, the electric air valve (situated in the compressor assembly) opens and lets air out. With the system I am building for the KImperial, I won't need that exhaust valve. I plan to simply install a good old fashioned mechanical leveling valve like the ones found on every semi tractor trailer unit and every bus on the continent. Those are reliable and easy to replace if they do go wrong. To convert to this type of system I do need two other components though. I need a reservoir and a pressure switch. I have a reservoir all ready. It came out of my 77 NYB parts car. I need a pressure switch and the correct fittings etc to plumb it in. Since I am not using the compressor to inflate and deflate the shocks directly (but rather using the pressure in the reservoir to do that) I need a way to turn the compressor on and off when the pressure in the reservoir demands it. This would work exactly like the pressure system on your home shop air compressor. Sure, I can go buy a new pressure switch but like so many other projects I do, half the fun is trying to see if I can scrounge enough stuff to do it. Those pressure switches run about $30 too so I want to leave that as a last resort. ----- Original Message ----- From: "Jim Gathmann" <jim_gathmann@xxxxxxxxx> To: "3.3 3.3" <mopar33lv6@xxxxxxxxxxxxxxx>; "ImperialList ImperialList" <mailing-list@xxxxxxxxxxxxxxxx> Cc: "EEK EEK" <eek@xxxxxxxxxx>; "brad hogg" <chrysler1978@xxxxxxxxxxx> Sent: Saturday, May 03, 2003 8:18 PM Subject: Air Compressors I remeber (Brad?) someone memtioning that a good replacement for 90's Imp air suspension compressors are used units from 80's Cadillacs. Well I picked one up for $10. But I can't figure out how the thing hooks up- has 4 wires (ground, +12volts, and???), and 3 hose hookups.... This any similar to the Imperial's OEM compressor? How does the OEM one wire and hook up? __________________________________ Do you Yahoo!? The New Yahoo! Search - Faster. Easier. Bingo. http://search.yahoo.com