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Brian, Auto Service Technician
Category: Ford
Satisfied Customers: 1227
Experience:  5 years Ford Technical Hotline/Service Engineer. 2005 Ford Master Cert. Automotive Technology degree
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2003 Lincoln Navigator: the air relay is..dead battery..crank..shifter

Customer Question

I have a 2003 Lincoln Navigator, and the air suspension is not responding in the front. The rear suspension is fine, and the air relay is new. I also have a dead battery every time i try to crank it, the radio lights, and shifter lights stay on when the vehicle is not cranked. Please, help!
Submitted: 8 years ago.
Category: Ford
Expert:  Brian replied 8 years ago.
You might have a height sensor problem. If the height sensor tells the computer wrong information, the computer may be thinking the vehicle is at the right height. Keep in mind when testing that if any doors are open, the system will not change height.

Before worrying about the height, get the battery situation resolved. Use a voltmeter to check battery voltage when trying to start the engine. If you have a Check Air Ride message, then there are trouble codes stored, which a Ford compatible scantool can retrieve for assistance in diagnosis.

The items staying on could be an ignition switch, wiring, or fuse box problem. Once the battery is charged, use the voltmeter to check the fuses. See if the fuses are powered all the time, some of them should be but others should only have voltage in the RUN position of the key.

It sounds like the battery voltage may be too low to operate the Air Ride Control module, so it is not turning on the relay. There are some fill valves that must open to allow air into the front air springs. If the module does not turn on at all, then the height will not adjust properly.

So, basically you need to get the battery charged first, then see if the voltage stays above 9.6 when trying to start the engine. If it drops below 9.6v, the battery needs to be replaced. With a new battery, re-evaluate the situation to see if it fixes any other issues.
Customer: replied 8 years ago.
The battery is replaced an the Navigator cranks fine now. The front suspension is still not responding, is there any way to check the soleionds, or the ride height sensors without going in and replacing them?
Expert:  Brian replied 8 years ago.
You will need a voltmeter to check the height sensors on the front. They operate on a 5 volt scale. You can detach the lower mount of the height sensors, and slide them in and out while watching the voltage. You should see a smooth change in voltage, from .5v when extended to 4.50 volts when compressed.

Here is a diagram showing how to connect the voltmeter (the height sensors must be plugged in, so you will need to backprobe the connector or pierce the insulation of the wires with a pin to make contact with the wiring. I prefer backprobing so as not to damage the wiring insulation. But if you do use a pin to pierce through, you can seal up the hole with silicone afterwards. Backprobing is done by inserting a paperclip through the back side of the connector so it goes down in and contacts the terminal inside.


You don't need 2 voltmeters, I was just trying to show how it hooks up between pins 1 and 2 the same way on each side.

You can test the solenoids by unplugging them and running power and ground to them via jumper wires. Power is pin 1, ground is pin 2, use the diagram above to see the wire colors. The module supplies them with 12 volts to open them. Don't leave them connected to power too long to prevent overheating them. Once they are open, do your relay switch trick, to get the compressor to run, and if the solenoids and lines are not clogged, the front should raise. You may need to remove the solenoids and verify they flow or not, and check the air line from the compressor to the front solenoids.

The four wheel air suspension system is comprised of the following components:

  • service switch
  • control module
  • two front height sensors
  • one rear height sensor
  • compressor and drier assembly (includes vent solenoid)
  • air lines
  • front and rear air spring and shock absorber assemblies
  • four air spring solenoids
  • compressor relay

WARNING: The service switch for the air suspension system must be shut off prior to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by turning off the air suspension switch located in the jack storage area in the rear of the passenger compartment. Failure to do so may result in unexpected inflation or deflation of the air springs which may result in shifting of the vehicle during these operations.

WARNING: Do not remove an air spring under any circumstances when there is pressure in the air spring. Do not remove any components supporting an air spring without either exhausting the air or providing support for the air spring to prevent vehicle damage or personal injury.

Air Suspension Pneumatic Diagram

Item Part Number Description
1 5319 Air compressor and drier
2 5B322 Air line T-fitting
3 5B321 Air line union
4 Air line Y-fitting
5 18945/5311 Air spring and solenoid