So the past month or so at random times my air suspension light would come on. It seemed to do it mostly when driving down the highway. I know one of my tires is in need of balancing, so I figured the vibration was messing with the ride height sensor, nope wrong.

Fast forward to yesterday. The wife comes home, walks in the door and proceeds to tell me the truck (01 Navigator) is shot. After a split second of panic, I reminded myself of how she can be quite the drama queen at times. So I asked her what she meant. She tells me of how the ride home was just horrible, a lot of banging when hitting bumps, turning around corners, and an overall rough ride. So I look outside and find the rear of the truck sitting down on it's axle. Okay so now the panic is over because the truck is fine, it's just an issue with the air suspension not pumping up.

The first thing I checked were the fuses, both were good. Next I went right for the compressor relay figuring that at it's connector I can test for power and continuity to the compressor motor, effectively killing two birds with one stone. I unplugged the flat 4-wire connector from the relay and immediately noticed corrosion and heat marks on the terminals. Cleaned all the contacts, put it all back together, started the engine, and the suspension pumped right up to where it belongs.

Hope this helps someone else that might have a similar problem. The relay is in front of the right front passenger tire. This makes it susceptible to road crud and a lot of water.

 

I believe I'd be packing that connector with die-electric grease.

 

I used a similar substance that I use in the electrical trade. It's called penatrox and it's function is to prevent corrosion from developing. I use it on battery connections all the time and never had any corrosion on any of my battery terminals.