Town Car air suspension problems

[Town]

Sounds like the compressor is not running when it should and you are uncertain of the connections to get the compressor running automatically? Attached are the electrical diagrams.

When the suspension height sensor detects a low body condition it signals the air suspension module that grounds its pin 23 and Dark Blue with yellow tracer wire to the air suspension compressor relay pin 85 and the relay provides power to the air suspension compressor. So is that relay pin 85 grounded? The circuit is powered by fuse 12 (30A) from the engine compartment fuse box and provides power through Light blue with pink tracer wire to pins 30 and 86 on the relay. The solenoid between pins 85 and 86 on the relay close (when power and ground applied to relay) the switch for power to run from pin 30 to pin 87 on the relay. Pin 87 on the relay is connected to the compressor through a Grey with red tracer wire. The compressor should run.

The air suspension system should be sealed (unless there is a leak) and the only way of allowing a pressure drop is for the air suspension module to power its pin 24 and provide power to the vent solenoid on the compressor through the pink wire. Check to see if that is being powered to release air from the system.

The height sensor under the left rear suspension must be working correctly. It is a straight tube that can get shorter when the body is low and needs air or longer when the body is high and needs to lose air. An electrical signal tells the air suspension module that the suspension is at the right height (trim height). Suspension height changes occur as needed when the car is stationary but delayed by about 45 seconds when the car is being driven.

It is possible to raise the rear suspension by switching off the suspension in the trunk and removing the air suspension module connector and grounding the compressor relay to start the compressor and providing 12 volts at the module harness connector (BR/PK wire pin 13 and T/W wire pin 25 connectors harness side) to the rear air spring solenoids to open them. Once the suspension is up to level remove the connectors for the rear spring solenoids and remove the ground to stop the compressor. The EVO power steering assist reduction will be disconnected while the air suspension switch is off and the connector removed from the air suspension module (just in case you take a drive and wonder what is up with the steering).

Good luck.

 

[nrld5239]

Sounds like the compressor is not running when it should and you are uncertain of the connections to get the compressor running automatically? Attached are the electrical diagrams.

When the suspension height sensor detects a low body condition it signals the air suspension module that grounds its pin 23 and Dark Blue with yellow tracer wire to the air suspension compressor relay pin 85 and the relay provides power to the air suspension compressor. So is that relay pin 85 grounded? The circuit is powered by fuse 12 (30A) from the engine compartment fuse box and provides power through Light blue with pink tracer wire to pins 30 and 86 on the relay. The solenoid between pins 85 and 86 on the relay close (when power and ground applied to relay) the switch for power to run from pin 30 to pin 87 on the relay. Pin 87 on the relay is connected to the compressor through a Grey with red tracer wire. The compressor should run.

The air suspension system should be sealed (unless there is a leak) and the only way of allowing a pressure drop is for the air suspension module to power its pin 24 and provide power to the vent solenoid on the compressor through the pink wire. Check to see if that is being powered to release air from the system.

The height sensor under the left rear suspension must be working correctly. It is a straight tube that can get shorter when the body is low and needs air or longer when the body is high and needs to lose air. An electrical signal tells the air suspension module that the suspension is at the right height (trim height). Suspension height changes occur as needed when the car is stationary but delayed by about 45 seconds when the car is being driven.

It is possible to raise the rear suspension by switching off the suspension in the trunk and removing the air suspension module connector and grounding the compressor relay to start the compressor and providing 12 volts at the module harness connector (BR/PK wire pin 13 and T/W wire pin 25 connectors harness side) to the rear air spring solenoids to open them. Once the suspension is up to level remove the connectors for the rear spring solenoids and remove the ground to stop the compressor. The EVO power steering assist reduction will be disconnected while the air suspension switch is off and the connector removed from the air suspension module (just in case you take a drive and wonder what is up with the steering).

Good luck.

Thank you for this detailed info, it seems that we are not getting the ground signal from the module, if I use a power probe iI can make compressor run. when this first started to create a problem the compressor would run after I turned on the key, but the rear would not go up and we could not hear any air escaping from front to back of car..? Even when we jump the compressor the rear will not go up??
I will check these wires that you are pointing out to see what happens and will respond then. thanks for letting me know how to get the car back up, I am over 550 miles from home, can the car be driven like that for this distance?

thanks a Million!!

 

[Town]

The suspension module is broken or the height sensor is broken. To raise the suspension the module needs the signal from the height sensor that body is low and then it will ground the cpmpressor relay ground circuit and the compressor will run and the module will open the two rear spring solenoids and the car will raise. So you can power the rear solenoids the way I said with the compressor running (you ground the relay circuit or power the compressor directly) and the suspension should raise but you must disconnect the power to the solenoids once the car is up to trim height. I hope this works and the air springs do not leak.

It may depend upon how smooth the roads are and how fast you drive. I would not drive your car for 550 miles with the suspension riding on the bump stops. For a short distance maybe but not for that long. But I have no experience of driving the Town Car under those circumstances.

Good luck.

 

[nrld5239]

I found the connector in the trunk for the air bags and started to check with DVOM for power readings and was getting eratic values, when I checked the ground wire the compressor kicked in and the rear end raised. Beginning to look like a gound issue with the ground wire G406, how do I find that ground wire where it is attached to the car?
should probably check for a good ground to chassis on ground wire # G201 also, do you have a location on each????

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[Town]

Sounds like you are making progress.

Attached are the documents showing the locations of G101, G201 and G406. The G406 looks like the trunk lid latch, so if the rear lights and trunk lid work, then perhaps the problem is in splice S499 (splice of the two spring solenoid ground wires before G406) which is close to connector C457F located: "Below center of rear package tray, near floor of trunk".

Good luck.

 

[lghbob]

I'm the old man with the long post a few pages back... Long and short... Decided not to do anything to repair....
Results as follows....
5000 miles later, still running the car with air suspension off. Car stays level, and while the ride may be a bit stiffer, no problem. Haven't put a really large load in back seat or trunk... max maybe 250 lbs in trunk. The car stays level without turning the compressor on at all. Just to test and see if the compressor still works, once in a while, will turn it on. It runs for about about thirty seconds and shuts off, then about two minutes later, runs again... and again and again. so we just leave it off.
Without knowing how the internals of the system works, I'd guess that the "air bag" is solid, with no leaks, and that when the compressor is off, the bag valve automatically seals, keeping the car at whatever level it was at when the compressor shut off.
Given that, my next guess would be that somewhere in the line between the compressor and the "bag" there is either a small leak, or the pressure switch is faulty.

I still wonder if a sudden deflation while driving would be possible, but never having heard of this happening, have put it out of mind.

Car still looks great... Will come back next year to report on the status Figger I've saved about $500+ so far... that's about a third of the value of the whole car.

 

[Town]

I'm the old man with the long post a few pages back... Long and short... Decided not to do anything to repair....
Results as follows....
5000 miles later, still running the car with air suspension off. Car stays level, and while the ride may be a bit stiffer, no problem. Haven't put a really large load in back seat or trunk... max maybe 250 lbs in trunk. The car stays level without turning the compressor on at all. Just to test and see if the compressor still works, once in a while, will turn it on. It runs for about about thirty seconds and shuts off, then about two minutes later, runs again... and again and again. so we just leave it off.
Without knowing how the internals of the system works, I'd guess that the "air bag" is solid, with no leaks, and that when the compressor is off, the bag valve automatically seals, keeping the car at whatever level it was at when the compressor shut off.
Given that, my next guess would be that somewhere in the line between the compressor and the "bag" there is either a small leak, or the pressure switch is faulty.

I still wonder if a sudden deflation while driving would be possible, but never having heard of this happening, have put it out of mind.

Car still looks great... Will come back next year to report on the status Figger I've saved about $500+ so far... that's about a third of the value of the whole car.

I have not read your earlier post explaining your issue. Based upon this post, you are correct that the air spring solenoids are closed by the air suspension module before the compressor is switched off by the module. Since the air springs are not leaking the possible problem with the cycling compressor is the suspension height sensor being faulty or the air suspension module is faulty. There is no air pressure sensor in the system, and an air leak in the line between spring solenoids and compressor would just increase the time to inflate. If the suspension module powered the vent solenoid when it should not then you would hear the air escaping at the compressor.

The compressor adds air to the air springs (increasing air pressure in the springs and stiffening them) until the height sensor reaches trim level. In your case that trim level may be too high (higher than normal pressure). The height sensor constantly monitors the suspension height and updates the suspension module if the suspension drops or raises so that the suspension module (when car is stationary or after a 45 second delay if moving) can raise or lower the rear suspension to trim height.

It does not sound like the suspension is dropping but may be too high so the height sensor is likely faulty. The Ford dealer tech can attach a scanner and read the suspension trim height voltage being sent to the suspension module and confirm whether the height sensor is faulty. If the height sensor is not faulty then likely the suspension module is faulty.

Good luck.

 

[cpmet200]

Does anyone know why the rear suspension of my Town Car is actually lifted? Sometimes it works ok but lately it hasnt been working properly. Any help would be greatly appreciated

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[rip1212]

I installed Moog Variable Rate Coil Springs and I could not be any happier. The ride is the same and I know that I'll never scrape the arse end again.

All2Kool, im looking to do the same for my 2003 Lincoln Town Car. But the Moog Part No: CC865 , don't come with the rubber isolators like the other kits do. (The Arnott kit and the Suncor Kit all have some rubber top and bottom pieces that are suppose to go on the top and bottom of the springs)

Are the rubber Isolators needed to install the Coil Springs and replace the Airbags?

 

[dave42]

All2Kool, im looking to do the same for my 2003 Lincoln Town Car. But the Moog Part No: CC865 , don't come with the rubber isolators like the other kits do. (The Arnott kit and the Suncor Kit all have some rubber top and bottom pieces that are suppose to go on the top and bottom of the springs)

Are the rubber Isolators needed to install the Coil Springs and replace the Airbags?

It has been a couple years since the above question, but I'll add some info. Research seems to indicate that some vendors include the isolators on the Moog CC865 and some don't. I just ordered these springs from Rock Auto, and although the picture on their site did not show the isolators and there was no mention of them in the specs, the isolators were in the box with the springs when they arrived.

 

[Tonittt]

The suspension module is broken or the height sensor is broken. To raise the suspension the module needs the signal from the height sensor that body is low and then it will ground the cpmpressor relay ground circuit and the compressor will run and the module will open the two rear spring solenoids and the car will raise. So you can power the rear solenoids the way I said with the compressor running (you ground the relay circuit or power the compressor directly) and the suspension should raise but you must disconnect the power to the solenoids once the car is up to trim height. I hope this works and the air springs do not leak.

It may depend upon how smooth the roads are and how fast you drive. I would not drive your car for 550 miles with the suspension riding on the bump stops. For a short distance maybe but not for that long. But I have no experience of driving the Town Car under those circumstances.

Good luck.

Hi, how much power goes through suspension solenoid? According to My measurement I have 4.97V.