Basically that'* it. The key isn't in the car, nothing is turned on, it'* not the antenna motor and it'* not the blower motor (that'* disconnected because it won't turn off). It'* an electric pump-like whirring sound, almost like a fuel pump but it comes from under the hood. When I replaced the battery it came on immediately after I hooked up the new battery and ran for about 10-20 seconds or so. Then later, while I was draining and re-filling the radiator, it came on again for about 20 seconds, stopped, then came on again--and again it was for a very short period of time. Very strange. Any ideas?
Keith

ELC (Electronic Level Control) compressor. Comes on when the level sensor detects more weight, and adds air when needed.

It will come on more often if you have a leak in the system.

Sounds as if it may be the air compressor for your leveling control. Are your rear struts leaking air?

The second time I heard the pump was when I was jacking the car up to drain the radiator--that might well have caused the rear shocks to compress and leak (if they leak). How do you tell if the rear struts are leaking? Just listen?
Keith

Try techinfo. Link at the top of the page.

If the pump runs more than once in a 6 hour period of time, it'* going to bite you sooner or later.

You'll know when later is because your battery will be dead. Unfortunately for you if you have CCR (computer command ride) also (ride control buttons on the console) it'll cost you that system even if it still works when you replace your rear struts. No loss there, though.

Well I haven't heard the pump in a couple of days, so maybe it was just pumping to make up for sitting for a year in a field. It also has a manually operated switch in the trunk right next to the trunk latch. Says "OFF" and "ON" and has a schraeder valve. When you press "ON" you can year a pump running, "OFF" and it quits.
Thanks again.
Keith

That'* your utility inflator which is part of the system. It won't do jack for the struts, but it'll fill a soccer ball (or a tire if you have extreme patience). High-pressure (70psi) low-flow.