'98 How do I deflate air springs with broken ride height sensor?

tadams

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As the title suggests... 1998 with non-functioning height sensor. I've been running it manually with the switch off, and ride height where I wanted it to be. Took it to a tire shop and they turned the trunk switch back on afterward. I immediately turned the switch back off as soon as the car was rolled out to me but it was already too late.

I've previously used a technique for jacking the car body up in the rear, letting the rear axle hang loose, and allowing the system to purge itself but must not be remembering how to do it correctly. Anyone have any pointers on this technique or know of something else to try? I've already forum searched and googled for hours, to no avail.
 
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Why don't you replace the height sensor(s)?

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Why don't you replace the height sensor(s)?

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Because it's no longer available; for years, now.
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Loosen the solenoid on the air spring one click it should allow the air to escape
I was hoping to remember this other way, as I'm physically unable to get under the car, myself. (Medical problems)
 
Because it's no longer available; for years, now.
Maybe no longer available brans new from Ford Motor Company. But there are dozens of sources of new after market sources and if OEM is that important, there are very clean used ones on eBay.

If you want one this part IS available.

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I was hoping to remember this other way, as I'm physically unable to get under the car, myself. (Medical problems)
A more difficult way would be to pull a line at the compressor. However, one has to be very careful not to damage the grommet holding the line into the compressor.

Or moving a height sensor (Requires getting under the vehicle) to far extreme signaling the ride height is too high.

It may be possible to use ForScan to do this electronically, I do not know how to do that or if that is possible as I just remove a solenoid.

Solenoid removal .............
Drive the vehicle up a set of ramps. (Shut off the key AND the system switch) Get under the ride. Disconnect the connector to the solenoid. Remove the retaining clip. Move the solenoid to the first removal position. Air will come out in under a minute. When the air is done coming out, the solenoid can be removed fully if needed. (Recommend replacing the O rings on solenoid)

Or maybe it is time to find other labor to do this work.

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I've previously used a technique for jacking the car body up in the rear, letting the rear axle hang loose, and allowing the system to purge itself but must not be remembering how to do it correctly. Anyone have any pointers on this technique or know of something else to try? I've already forum searched and googled for hours, to no avail.
The system does not purge itself!
The system (in theory) is closed. There are no openings in the rear or anywhere in a system that is functioning correctly.
The only opening is at the compressor and that opening is controlled by signals from the height sensor to the compressor.

By hanging the rear axle with a height sensor, the height will be too high. With key on and engine off, the system will open at the compressor and let air out at the compressor. But only so much no matter what signal the height sensor is reporting. The system is designed to have a minimal amount of air in it.

With no height sensor in that position (there is only one in the rear on a solid axle) "hanging" the rear axle does nothing.

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Maybe no longer available brans new from Ford Motor Company. But there are dozens of sources of new after market sources and if OEM is that important, there are very clean used ones on eBay.

If you want one this part IS available.

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Not that I have located. This is a '98 model. The only ones aftermarket are for '03 and later and are mounted and designed quite differently. An entire new mount would have to be fabbed in order to use the later model, although I have figured out voltage is the same.
 
The system does not purge itself!
The system (in theory) is closed. There are no openings in the rear or anywhere in a system that is functioning correctly.
The only opening is at the compressor and that opening is controlled by signals from the height sensor to the compressor.

By hanging the rear axle with a height sensor, the height will be too high. With key on and engine off, the system will open at the compressor and let air out at the compressor. But only so much no matter what signal the height sensor is reporting. The system is designed to have a minimal amount of air in it.

With no height sensor in that position (there is only one in the rear on a solid axle) "hanging" the rear axle does nothing.

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That may be why I was successful before? The height sensor is still installed and electrically plugged in, yet it no longer reads correctly and will raise the vehicle so high that it creates a limp mode to engine power with a only a "Trac Active" warning on the dash. There are no codes; nothing for ABS sensors or otherwise
 
Not that I have located. This is a '98 model. The only ones aftermarket are for '03 and later and are mounted and designed quite differently. An entire new mount would have to be fabbed in order to use the later model, although I have figured out voltage is the same.
There are several on eBay. This is just one.


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Supply and demand

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To answer the original question...

Remove connector C251 from the Suspension/EVO Steering Module, jumper pins 12, 25 & 24 on the connector together and apply 12 Volts to the jumper.

Relevant wiring diagrams and connector pin out attached.
 

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    1998 Town Car C251 Pin out.webp
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To answer the original question...

Remove connector C251 from the Suspension/EVO Steering Module, jumper pins 12, 25 & 24 on the connector together and apply 12 Volts to the jumper.

Relevant wiring diagrams and connector pin out attached.
Precisely the kind of thing I needed to know! THANK YOU!
 
Alright, y'all... So with etinpa's reply I got to thinking and, sure enough, found a video where someone else had the same idea. Use the plug behind the rear seat to falsely power up the solenoid(s) and pull the hose at the front to let the pressurized air escape.

Posting it here, in case someone else after us needs it. Not my video and I own no rights to the video:
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