1998 Expedition Air Suspension Issues

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gt350ed

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Howdy! I used the Search tool to no avail. I have a 1998 Expedition 4x4 automatic with air suspension. I've owned it since 2003. I absolutely love this car. It has about 145,000 miles. Several years ago, I replaced the rear bags. Have not had any issues since. However, for quite some time the air compressor has been much louder than typical. I figured it was going to need replacement, but it has always done the job, so I put up with it.

A few weeks ago, I was visiting my local tire shop. When I started the car to leave, the compressor started doing its job and within a few seconds, I heard all kinds of racket from the right front where the compressor is located and then nothing. It sounded like the compressor blew up, threw a rod in the little motor or whatever.

I drove home and it held air in the suspension UNTIL I disconnected the dryer from the compressor. Then the rear sagged. I removed the compressor and jumped the wires. It seems to have seized. No surprise. So, I ordered a used one off of eBay from a company that guarantees their products. When I installed it and plugged it in, nothing happened. Both the small "air suspension" fuse under the dash AND the HUGE fuse in the Power Distribution Box under the hood appear to be fine. So, then I jumped the eBay compressor and it seems to spin the electric motor fine. Not sure if anything else is supposed to happen by just jumping the hot and ground leads.

So then, I bought a replacement relay USED. Thats the bat-shaped piece mounted under the right headlight. It too is guaranteed to have been tested and working. I installed it today, NOTHING. The "Suspension" switch down by the passenger kick panel is turned on, but when I start the car, the compressor does not come on. Its as if juice is not getting to the compressor.

HELP!! Any ideas?

Thanks.

Ed
 
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gt350ed

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Bump! No help here? No experience in this subject? Have I posted in the wrong area?

Thanks.
 
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gt350ed

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Does the installed compressor run with the relay bypassed?

I assume you mean to "bypass" it to see if the relay is the problem. Not sure how to do that. Electrical is not necessarily my strong suit.

I DID jump the compressor heavy red and black leads to the battery and the compressor ran. Or at least the electrical motor attached to the piston/rod "compressor" portion ran. Not sure if both portions were supposed to do something with this type of "jump". The other two smaller leads were not part of the jump. I don't know what they do.
 

BAD RONALD

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With the compressor installed, unplug the relay and jump lead contacts with a stout wire (bypassing the relay) to see if the compressor activates and raises the ass end of the truck. This worked for me and told me the OEM relay on my '01 was bad.

Be aware that the doors on the truck need to closed for the air ride system to activate.
 
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gt350ed

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With the compressor installed, unplug the relay and jump lead contacts with a stout wire (bypassing the relay) to see if the compressor activates and raises the ass end of the truck. This worked for me and told me the OEM relay on my '01 was bad.

Be aware that the doors on the truck need to closed for the air ride system to activate.

I apologize for my ignorance, but when you say "unplug the relay and jump lead contacts", I don't know what that means, nor do I know WHICH lead contacts you are referring to. The wire plug going into the relay "contacts" 3 or 4 leads. I cannot recall, and I don't have it in front of me. Am I misunderstanding what you are saying?
 
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gt350ed

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Yes, the relay DOES have "A,B,C,D". I will check out the link you have provided, proceed and then report back. Thank you so much.

Your relay needs to show four pins labelled A,B,C,D for my advice to be any good.

The compressor harness plugs into the relay. Unplug the harness, locate harness side contacts "A" and "B", read post #2 in the link and follow diagram "Check Air Compressor Relay"

97 Exp Air suspension question ? - Ford Truck Enthusiasts Forums
 
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gt350ed

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I wanted to report back and thank Bad Ron for his assistance in trying to solve my air suspension issues. Unfortunately or fortunately, depending on your point-of-view, for me reality set in. I got to thinking that although I LOVE my Expedition, I cannot ignore that it is a 17 year old truck at this point. And, as relates to the air suspension system, it is quite realistic to assume that I may be chasing more than just a compressor and relay. If not now, most likely SOON.

So, I did a fair amount of research on making the conversion from "air" to standard springs and shocks. As one person put it, you can buy an entire conversion kit for the price of just one ride height sensor. Not having actually checked the price of a sensor, I'm nevertheless of the opinion that he is correct.

Today, I took delivery of a Monroe kit which includes rear springs, rear shocks and front coilover shocks. The entire cost was $227.00, INCLUDING sales tax. Shipping was free. Having read MANY reviews of this particular kit, including from those that installed it on the same exact year and model of Expedition that I have, I can't help but be a happy camper. The Expedition is backed into my garage ready for the conversion. Having reviewed a video of the entire process, I don't expect any issues relating to the install
 

Bedrck47

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Ed Just a curious question. In your original post you say

" Both the small "air suspension" fuse under the dash AND the HUGE fuse in the Power Distribution Box under the hood appear to be fine."

Just how did you test them??
 
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