Hi, your symptoms point to a bad air compressor relay, this is a relay located under the vehicle around the bumper area. Does not look like a relay because its aluminum and finned. Follow the compressor wires to this relay, disconnect and examine the connector. If the connector looks bad, (corroded pins), replace it and recheck. If looks okay either swap with a known good relay or replace. This relay does not work like a conventional relay, its more of a electronic transistor, or module, and jumping will not let the solenoids work, if you where jumping at this aluminum finned component that supplies voltage to the compressor.
I'll go out and see if I can find it. The one I jumped that made the compressor run is immediately above the compressor in front of the windshield washer reservoir. On that one, there were 2 larger female spade terminals across from one another that I judged to be the power and load sides of the relay that get switched when the solenoid pulls in the switch. The power side is hot all of the time and when I jumped it to the load side after unplugging the relay, the compressor came on but it did not put air in the air bags. Same situation and result when jumping that relay with the new compressor on. That relay must be switched with a ground because one side on the solenoid is hot all of the time also. Either that or it just happened to be calling for air when I checked it.
Dang, I wasn't quite done yet. When I jumped the relay that I described above, I didn't jump the solenoid wires. I took them out of the mix by jumping direct across the relay with the power wires. That made the compressor come on as I said before but to no avail. The relay you
'The relay you're talking about must control whether air can get to the air bags too. Is it possible to make the compressor run and make the air bags take air by jumping the relay you're talking about the same way I did the other one? Or is there a way to test the relay without swapping it out? I saw some of the relay prices when I ordered the compressor and if this is one of those, they get kind of pricey to just buy one to swap. No problem if this is almost sure to be the problem but just wondering. By the way, over the weekend I fashioned a valve and plastic air line out of some parts I had in the old tool box that mated up with the air line where it connects to the compressor. I supplied the valve with a quick connect fitting that the air hose just plugged in to like an air tool so I got about 80 lbs. of air in the shop air compressor and plugged it on to the connector and then opened the valve to the car air line. It should have aired up the air bags in my own perfect mind but it didn't. Something is stopping the air between the compressor and the air bags. Will the relay take care of that too? Sorry for all of the additional questions. I've just always needed to know how things work for some reason. I'm going to do what you told me to do. I'm not second guessing you, I'm just hungry to understand how it all comes together and works.
Hi, sorry for the delay, Im back, give me a second to review...
Hi, if 4 air bags will also have 4 vent valves, if 2 air bags will have 2 vent valves in rear. Yes there is some electronics to the air bag system that really is not capable of just simply testing. Best way I found to test is scan or command with a wds or IDS scanner, see if you are able to command vent solenoids on and off with your scanner and let me know, If not, trying a known good relay, or used relay is the cheapest alternative from the 3500 up scan tool to command components to diagnose 100%.
Atleast look at connections, no bench test for relay since it incorporates electronic transistors, possibly working at a duty cycle.
Have seen bad connectors, but rare,
I'll check with the guys in the shop in the morning and see what their scanner will do. But first, I know where there's another relay. The bosses Mom has a 2003 Navigator that is a dead on match to mine. She is gone to Arizona for the winter and the guys in the shop have the keys to the garage. I'll see if they can grab that one in the morning before the scanner test and we'll see what it does. Thanks so much. I'll get back to you as soon as I have any results worth reporting. Sure will be good to get that thing fixed. I tried driving the 30 miles to work and back while the frame was riding on the axles. I should have been peeing blood and having a couple of vertibre fused together by the time I got home. Now, don't I wish I had done this 10 days ago. Dang!!!
Try a known good relay, then let me know. Next scan tool must be capaible of monitoring, controlling and pulling codes from all modules, or computers on the vehicle.
Yes, sure it is possible to diagnose without correct equiptment, but may take 100's of hours and extremly expensive tools.
Yeah, if the one on the bosses Moms car makes it work, the guys in the shop will probably want to put my bad one on hers so when she gets back and the suspension won't work, they'll look like genius's by finding the problem in 5 minutes. Thanks again. Get some sleep and we'll finish this chat up in the morning.
Good Morning Nickssticks,
I couldn't stand it so I went out and traced the wires from the compressor down. A nice 4 wire loom that went down from the compressor and back and then turned toward the front bumper and then came right back up in front of the compressor and went right to the relay that I have been talking about. No matter the location and no matter the material it made of and the appearance. This one is gray plastic. But, it is the relay that you have been talking about too. The 2003 Navigator may be a freckle different than the town cars, etc. That's OK. Your advice is still on target because I haven't tried swapping that relay out yet. It's entirely possible that this relay is no good. I shorted across it and the compressor ran but wouldn't fill the bags. Then I replaced the compressor. Dumb. If the compressor runs when you bypass the relay, the compressor isn't bad, but that sure points to a relay again doesn't it. OK, I'm off to work in an hour and a half. I'll drop you a note when a different relay is installed.
Relist: Other. I had such good luck with Dodgewrench a couple of years ago that I think he spoiled me. That guy was so intelligent and so helpful. He was ahead of me every step of the way. The guy I got this time has been OK but just didn't jump out of the pack like I experienced before. For instance, after knowing the model and year, described the appearance and location of the relay we were discussing completely wrong. Also, didn't give me an answer about what could be stopping air from getting to the air bags when I manually apply shop air to the air line off the compressor. Recommended a new relay and when that didn't fix it, copped out and said take it to Ford. I just feel like there is someone else on duty there that may be of more help to me on this particular problem. Thanks
Edited original question:
My 2003 Navigator has a problem with the air suspension. The compressor won't come on by itself anymore. Since I'm not very smart and like to pretend that I'm made of money, I bought a new aftermarket compressor and put on it. Still have the problem. It's been 10 days since it went down and in the meantime, I jumped across the terminals where the compressor relay plugs in. I jumped from the heavy power lead that's hot all the time to the compressor power lead and the compressor runs. It just won't pump anything into the suspension. I realize that by doing that, I didn't tickle anything on the activation coil side of the relay and that the system may need to see that there was a call for pump operation by monitoring the coil circuit for activity in order to open a valve letting air to the bags. That's a big bunch of guesses and assumptions on my part.
I was going to need the compressor soon anyway I think because the old one was getting very loud and taking too much time to pump up. Then, I put this question to you experts at "Just Answer" and was told that I needed a new compressor relay. I got a new relay from Ford yesterday and that didn't fix anything either. The "Check Suspension" light comes on in the dash and when I run the check system routine with the dash controls, it will read "Suspension OK" for about 2 seconds and then goes back to "Check Suspension". I can't even get any air to the air bags on any of the wheels when I connect shop air to the line that feeds the suspension out of the compressor. Is there something inline that would stop air from getting to the suspension on all 4 wheels and if so, can I go around it or jump something to force it to open? I would like to be able to pump it up a little so I can use it if I have to. What steps do I need to do to start diagnosing the problem? Our construction shop has a code reader but not one of the real expensive ones if that helps. I can't tell you what kind it is but I can find out if necessary. Since I have eliminated the compressor and the relay, did I narrow the possibilities down far enough that it would be cheaper to just buy another part or two that could be causing this problem than it would be to take it to the dealership and have them put it on the scanner and fix it? Is there something I can check with a Fluke that would narrow the possible causes? I have some mechanical ability and can reason through a "go or no go" diagnostic chart. My problem is that I have no idea what this system has on it for controls or checks and balances and don't know where to begin trying to diagnose the problem. The suspension acted up once before on this car and when our shop had trouble with the diagnosis I took it to Ford and it cost me $1200 to get it fixed so I'm a little more interested in trying myself this time. I'm probably in over my head in the knowledge department and on the short end for necessary testing equipment to try this repair, but that's what you guys are good for. Anyone care to try helping me blunder through this? By the way, I can still take the new relay out and jump across from the power supply line to the compressor load line and get the compressor to run but still no air gets to the air bags.
Thank you for your reply. I do not know where the suspension module is. I know where the compressor relay is and the compressor and the air bags and that's about it. Of course, I have replaced both the compressor and the relay so I had to know where they are. I do have a test light and a good Fluke meter. I have a freind with a code reader that we plugged in to it tonight but it didn't come up with a code. I have an idea that it is one that won't read the suspension module. Probably just the engine problems. OK, do you think I'm being too stubborn? If it's that complex and the problem would be easily found with a dealership scanner, maybe I should reconsider and just go get the thing hooked up. I don't know. The problem is affecting all of the solenoids so I would guess you're right in assuming that it might be a problem in the module or somewhere before it divides out the decision making to the individual wheels. Can you still read out the trouble codes that are set through a series of light blinks on the dash if you jump pins on the scanner connection? Showing my age now!! One thing, when I jumped the compressor relay across the power supply leads, I did check the other 2 spades that go to the activation coil and one had voltage to it. Maybe that helps us decide whether the module has power to some of the pins or not. This may be way late, but while I've been waiting I have been looking at the owners manual and found out that there are at least 2 fuses that have something to do with the suspension. I haven't checked those yet so for tonight, let me check those and you can think about what I need to do if they are good and I'll try to check in with you in the morning. I think the old lady wants me to take her for a drink and at this point, I'm not in a hurry to jump into the whole process tonight. Sound good?
Finally got around to checking the fuses. Been a hectic day. Fuse #20, 30 amp OK, fuse #27, 5 amp OK, fuse #111, 50 amp OK. Switched out #20 and #27 anyway but they all light a test light on both sides of the fuse. I don't know where the suspension module is so if you could help me with that I will check the wires you mention above. Are all 3 supposes to read battery voltage?
I got the module out of the vehicle. The pins all look great. Still have a hint of white grease on all of them. I can't think that we're looking at a connection problem here at the module.
I think you're right. It's about got to be the module at this point. Can I power up the solenoids to get some air in the bags so I can drive it out to work? I'll get a module tomorrow. Thanks. If you send me the diagram and give me some info on powering up the solenoids, I'll pay you.