Expert: Skip Bollinger - 10/1/2007

Question
Skip you give excellent advice. My 1998 f250 air ride system is not working correctly. Drivers side is higher than passenger side. The compressor comes on momentarily when you turn the key over so I don't think that is bad. The check suspension light stays on all the time. Is there some sort of "leveling" sensor that may have gone bad? Can you lead me to a troubleshooting website or offer some advise on how to troubleshoot and repair this. I know your time is valuable but if there is a part needed I will buy it through you if available.
Thank you!
Tim Baxter

Answer
Tim,
  Man, do you know how to suck up!!! Really, thank you for the kind words. I'm a Parts Professional, NOT a Tech but I try to help as much as I can. Now to your question.
  I spoke to some of my customers today and not too many have seen the air ride system. Not many in this area can afford that option but the general consensus is there has to be a problem with the sensors OR wiring going to the sensors. Most said there is a "tree" in repair manuals to follow to diagnose the problem. If you go to a GOOD Public Library, in the Reference Section, you should be able to find a repair manual for your truck. You can't check out these books but you can find the pages you need to photocopy. The "tree" will be a diagnostic chart that gives you steps to follow and will say something like this:
  Turn on key.
     Listen for compressor.  
          If compressor does not run, check fuse and      relay. If it does, go to next step.   
  Then there will be another step to look at. As you can see by the paragraphing above, you do something and inspect something. Then it gives you the option to fix something or go to the next step. That is why it is called a "tree". It starts at the top very wide and slowly narrows as you get to the bottom of the problem.
  Please be warned that if it tells you to replace an electrical item, check the wiring going to that item carefully. A poor electrical supply to an object can make said object appear defective.
  Tim, I know this is a very "general" overview but it is the best I can offer. This system has a lot of components and most can cause the problem you describe. I think the Library is your best option. As far as parts go, I have seen nothing in the aftermarket. I think you are stuck with the dealer.
  Thank you for your question and good luck to you.
Skip