Anyone know about air suspensions?

aaronearles

aaronearles

Forum Member
I purchased a 98 Lincoln Continental last week and it was sitting on the ground with little to no air in the bags, so I get it home and jacked up, test the compressor with direct 12v, it's good. Test the solenoids with direct 12v, both good. Manually fill the bags by opening the solenoids with 12v and running the compressor with 12v, bags fill and hold air for days.

I start the car, and get "Check Ride Control" immediately. The guy I bought it from tells me the car was up and had no error message when he parked it, but it's been sitting for a year, and eventually leaked all the air out of the system. So the compressor is not seized, the lines, solenoids, and bags are all good. I have no way to test ride height sensors, and I have no power coming out of the compressor relay at any time, but I think that's because the system detects an error, and never tries to turn the relay on.

So I'm down to the following possibilities:

Bad Compressor Relay
Bad Ride Height Sensor/s
Bad Vehicle Dynamics Control Module

Right? It doesn't seem like any of these would go bad from sitting, but I don't know...
I did take the covers off the height sensors, and the circuit board underneath looks good on both, no burns or anything obvious. I also opened the Control Module, and there is no visible damage to it either, although when I start the car with it unplugged, I get no error message, it's like the car doesnt even have the air ride system. Plug it back in, and I get the message, so I'm thinking that the VDCM is what checks the systems components and displays the error message, so it must/should be good?

I've read that the relay only goes bad from excessive running of the compressor, like with a leak, so it doesnt make a lot of sense for that to be bad.

What do you guys think? If I can't figure it out, I'm going to disconnect the control module so no error msg is displayed, and run a switch in the trunk to manually feed the solenoids and compressor 12v so that I can manually fill the bags once in a while as they slowly leak. Any idea how long the system holds air with no major leaks, I'm thinking I could fill it everytime I fill the gas tank if I'm lucky, or of course less often would be nice.


Thanks guys!
 
make a jumper wire from the battery to the compressor to verify that its not the compressor. if it works id say its the relay.
 
I actually did jump power to the compressor and verify that it works.
Do you think a relay would go bad from sitting? Only reason I haven't just replaced it is because they're $100, so I'm trying to be sure.
 
I would go with trying the cheap fix first. Wire up and repair and trace relay wiring. My second most likely scenario for sure is ride height sensors. they are highly failure prone.

I have done a ton of work on these and it seems like everytime I spot a trend I find yet another new one of damage and neglect. I would suggest trying the go over the electrical first. You should be able to impedence test the ride hieght sensors. I would check all the grounds etc at the control module.
aaronearles said:
I purchased a 98 Lincoln Continental last week and it was sitting on the ground with little to no air in the bags, so I get it home and jacked up, test the compressor with direct 12v, it's good. Test the solenoids with direct 12v, both good. Manually fill the bags by opening the solenoids with 12v and running the compressor with 12v, bags fill and hold air for days.

I start the car, and get "Check Ride Control" immediately. The guy I bought it from tells me the car was up and had no error message when he parked it, but it's been sitting for a year, and eventually leaked all the air out of the system. So the compressor is not seized, the lines, solenoids, and bags are all good. I have no way to test ride height sensors, and I have no power coming out of the compressor relay at any time, but I think that's because the system detects an error, and never tries to turn the relay on.

So I'm down to the following possibilities:

Bad Compressor Relay
Bad Ride Height Sensor/s
Bad Vehicle Dynamics Control Module

Right? It doesn't seem like any of these would go bad from sitting, but I don't know...
I did take the covers off the height sensors, and the circuit board underneath looks good on both, no burns or anything obvious. I also opened the Control Module, and there is no visible damage to it either, although when I start the car with it unplugged, I get no error message, it's like the car doesnt even have the air ride system. Plug it back in, and I get the message, so I'm thinking that the VDCM is what checks the systems components and displays the error message, so it must/should be good?

I've read that the relay only goes bad from excessive running of the compressor, like with a leak, so it doesnt make a lot of sense for that to be bad.

What do you guys think? If I can't figure it out, I'm going to disconnect the control module so no error msg is displayed, and run a switch in the trunk to manually feed the solenoids and compressor 12v so that I can manually fill the bags once in a while as they slowly leak. Any idea how long the system holds air with no major leaks, I'm thinking I could fill it everytime I fill the gas tank if I'm lucky, or of course less often would be nice.


Thanks guys!
Click to expand...
 
A quick way I was able to determine if it was the ride height sensors on a 96 mark viii is to jack a corner of the car up a bit. After a few minutes the compressor should kick on because the corner you jacked up and the opposite diagonal corner are not equal in height. Just a thought.

~Eric
 
i know the mark vIII had a switch in the trunk to actualy turn the air ride off when being towed or for what ever reason. i think it was in the mark VII's also. there also a couple of places online that sell conversion kit to convert back to a coil spring for the older cars, not sure about a '98 though.
 
aimmotorsports said:
i know the mark vIII had a switch in the trunk to actualy turn the air ride off when being towed or for what ever reason. i think it was in the mark VII's also. there also a couple of places online that sell conversion kit to convert back to a coil spring for the older cars, not sure about a '98 though.
Click to expand...

all fords with air ride are like this
 
It is a vehicle hoist and or jack disable switch. What will happen is that the air compressor will run and run and run until the bags explode. Kind of a stupid design if you ask me. Not to mention the compressor wear and tear and the dead batterys that result from it as well.

aimmotorsports said:
i know the mark vIII had a switch in the trunk to actualy turn the air ride off when being towed or for what ever reason. i think it was in the mark VII's also. there also a couple of places online that sell conversion kit to convert back to a coil spring for the older cars, not sure about a '98 though.
Click to expand...
 
try testing the relay. unplug it, if there is no wiring diagram on the side take 2 jumper wires attatch one to a hot source and the other to a ground then take the relay and put the hot on one of the prongs touch the ground to the other prongs one at a time until you hear it click( if you get no click move the hot over one prong until you've tried them all if still nothing its bad) remember those two prongs those are the trigger prongs, get your trusty ohm meter out and test the resistance between the other posts. if there are two posts left over you should get no reading on the meter with no power to the relay and a zero or very low reading with power anything else and its bad , if there are three posts left over its a little harder to explain. the easiest way i can think of is to number them, so lets call the trigger posts "post 1" and "post 2" the others will be 3,4, and 5 you should get zero resistance between 3 and 4 and no reading between 4 and 5 with no power, when you put power to the relay it should reverse no reading between 3 and 4 and zero between 4 and 5. I hope this helps and doesnt confuse you to bad, I think it would be a four post relay so it shouldnt be too bad to test.
 
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