newbie with air ride question

Does anybody know if the height inputs on the height sensor are normally closed or open? If normally open I would think you could just cut both the high and low input wires. If normally closed than I would think you could ground both input wires at the sensor. If they are variable then maybe a resistor could be soldered in series of both inputs.
 
TheRebel said:
Does anybody know if the height inputs on the height sensor are normally closed or open? If normally open I would think you could just cut both the high and low input wires. If normally closed than I would think you could ground both input wires at the sensor. If they are variable then maybe a resistor could be soldered in series of both inputs.
Click to expand...

I thought you had it fixed :confused:

From the FLM service manual.

The height sensor is connected to the frame crossmember at one end and at the left rear upper control arm at the other end. The sensor gets shorter when the rear of the vehicle goes down and longer when the rear of the vehicle goes up. Magnets mounted in the lower slide portion of the sensor move relative to the sensor housing, generating a signal that is sent to the control module through two small Hall effect switches that are attached to the sensor housing.

Movement of the magnets determines switch opening and closing. At trim height, the switches remain closed and the module receives a trim signal. Upward movement of the magnets will open one switch to indicate a high condition. Downward movement of the magnets will open the other switch to indicate a low condition.
Click to expand...

99RAS_zps9313920f.gif


WARNING: THE VOLTAGE ON CIRCUIT 417 IS NOT B+ (12V).

I wonder where the instructions are that FroZone was going to post.
I figured it was just a bunch of hot air emanating from him.

_____________________________________________

Testing the Height Sensor (99 model)

Wiring:

  • Power Input - VT/OR -Violet/Orange
  • Ground - BK/PK - Black/Pink
  • Low Height Output - OR/BK - Orange/Black
  • High Height Output - PK/BK - Pink/Black
Tools Needed:

  • 3.3 VDC regulated power supply (2 AA, AAA, C or D cells in series)
  • DMM
Procedure:

  • Remove C468 from the height sensor.
  • Connect the + side of the power supply to the power input pin (where the VT/OR wire connects).
  • Connect the - side or the power supply to the ground pin (where the BK/PK wire connects).
  • Connect the black lead of the DMM to the ground pin
  • Connect the red lead of the DMM to the OR/BK wire pin. If the sensor is in the low position (shortened), the ohmmeter should read >10 MOhm (open). If the sensor is anywhere else, it should read <10 Ohms (closed).
  • Connect the red lead of the DMM to the PK/BK wire pin. If the sensor is in the high position (lengthened), the ohmmeter should read >10 MOhm (open). If the sensor is anywhere else, it should read <10 Ohms (closed).
The sensor switches have a possibility of 3 states:
  1. High line closed, low line open. (Suspension too low)
  2. High line open, low line closed (Suspension too high)
  3. High and low lines closed. (Suspension at trim)
I know what I would do to extinguish the Check RAS lamp. I'll let you decide your route.

Good luck.
 
Last edited:
no0c said:
.
[/LIST]The sensor switches have a possibility of 3 states:
  1. High line closed, low line open. (Suspension too low)
  2. High line open, low line closed (Suspension too high)
  3. High and low lines closed. (Suspension at trim)
I know what I would do to extinguish the Check RAS lamp. I'll let you decide your route.

Good luck.
Click to expand...

Looks to me that the high and low lines should be grounded.
 
That's the way I look at it ! Pretty simple operation, huh?

But I'll keep my air springs until the ole '92 resides in the bone orchard.
 
It did not work. :( I left everything connected and used scotch locks to tie the Black/Pink, Orange/Black, and Pink/Black wires together.
 
TheRebel said:
It did not work. :( I left everything connected and used scotch locks to tie the Black/Pink, Orange/Black, and Pink/Black wires together.
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And the RAS switch located in the trunk was in the ON position?
 
Yes

Also I ohmed the high and low inputs to ground while the car was sitting at normal height (light off). I think I was getting around 36 Mohm from either input to ground. Maybe a resistor is needed in series between the inputs and ground.
 
I'm not familiar with the term 'ohmed', but I'm guessing you measured the resistance. You think you were getting 36 Mohm? You're not sure?

If you were measuring 36 Mohm, that tells me both switches are open which is not what they should be at trim height. They should be showing <10 ohms or closed, essentially measure the resistance in the connecting wires. Remember the height sensor must be receiving power for the Hall effect devices to be operative.

My only other thought is, but it's hard to believe, because sometimes the light is on, and sometimes it's off, is that perhaps there is no voltage being delivered to the RAS module. Power is provided via fuse 17 (10A) located in the battery junction box under the hood and via fuse 8 (10A) in the interior fuse junction panel. If that were the case the lamp should be on solid. My next step, after checking the fuses and voltage at the fuses, would to be checking for voltage on the VT/OR wire at the connector to the height sensor.

Beyond that, I'm at the end of the rope. Sorry.
 
My meter showed 36.4 Mohm on one sensor wire and 37.4 on the other no matter where the level sensor was (fully compressed or fully extended while disconnected and out of the car). Sensor may be bad. I appreciate the help but for now I tired of messing with it. I may take another look at it when it warms up.
 
The sensor will not work without a voltage applied to it (~3.3V) !

Voltage is required to make the hall effect devices work !
 
noOc does that mean it only should pump at the 60 minute mark? I had an 86 Mark VII and it would reset and squat the car after you shut the key off and shut the door, I take it the town car does it differently? I had a neighbor that told me the same thing about my compressor going off. If it only does it once or only for the first 60 minutes I am ok with that. I travel a lot and just didn't want the battery to go dead if it sat there so I have been shutting the switch off in the trunk to make sure.
 
gramps said:
noOc does that mean it only should pump at the 60 minute mark?
Click to expand...

Only if it needs to and yes 60 minutes after the ignition switch has been in the off position.

I had an 86 Mark VII and it would reset and squat the car after you shut the key off and shut the door, I take it the town car does it differently?
Click to expand...

It will lower the suspension just like you mentioned .......... if and only if needed.

I had a neighbor that told me the same thing about my compressor going off. If it only does it once or only for the first 60 minutes I am ok with that. I travel a lot and just didn't want the battery to go dead if it sat there so I have been shutting the switch off in the trunk to make sure.
Click to expand...

You're safe. At the 60 minute mark the entire systems goes inert.
 
FWIW, I have multiple airbag Lincolns from 99-09. Only 1 gave me a problem & I attribute that to a driver allowing 14 guys to get in my 120 stretch. I replaced the bags myself for less than $200. If you are concerned about the under hood compressor, visit a salvage yard & pick up 1 as insurance for less than $20.

I have a set of springs which I purchased based on incorrect advice. "You won't be able to tell the difference." That was total BS. Stiffer ride, complaints from clients about the ride.

My 14 years of experience with Lincolns says there are very few problems with the airbag system. 1 of my cars has 460K & the airbags are still the OEM ones.
 
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