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I have a 1991 5th Avenue, 3.3 liter. A while ago, I had transmission problems and one dealer and Interstate Transmissions (and anothe, then name of which I forget) said I need a new tranny. It would shift hard, then go into 2nd gear and stay there. I took it to an automotive ELECTRICAL placem, and after 4 hours, found a bad wire. Ity worked! That was 3 years ago. Now it's acting up again. AND, as of yesterday, the engine won't start. Cranks fine, but it seems as tho there is no gas coming in. I let the car sit overnight, and had someone listen to the gas filler pipe while I turned omn the ignition and they heard a 1 second BUZZ... then the engine started! This morning, the car won't strat, so I had the wife listen, and there was no buzz. I am beginning to think that I have a bad ignition switch. Why? read on... I also have a peculiar problem... once in a while, usually when it's cold outside (50F or below) the speedometer doesn't work and the auto-locking door locks won't lock over 10pmh. After driving it for a few minutes (or till the engine heats up a little) it will kick in and the doors will lock and the speedo will work. Also, the ACCESSORY part of the ignition switch doesn't work electrically. (can't listen to the radio, etc)
I can also pull out the ignition key in any position the switch is in. Now, here's my MAIN question: Could a faulty ignition switch cause all of the above problems? Do the same contacts feed power to the fuel pump/door locks/speedometer/transmission etc? This is driving me nuts!
I do have the Haynes repair manual.
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Hi Duke,
I have the wiring diagrams for the car and yes the ignition switch could cause many but not all of those problems. If you have a voltmeter you could probe the wire coming to the switch (12 gauge red) and the wires that are supposed to be connected to it in the run position: 12 ga dark blue, 12 ga black, 22ga black/orange); and when you try the starter you should either see 12v on the 14 ga yellow wire or hear the starter relay click (located in the power distribution center box under the hood, driver's side). Those wires are all coming out the bottom of the steering column and you could carefully probe them with a pin and then attach the voltmeter to the pin. The 12ga red is hot at all times and is protected by a 40 amp fuse in the power distribution center. The ignition switch particularly the dark blue wire provides power to the engine controller which if lost will make for a no run condition. You could also check for fault codes stored in the controller memory:
turn the ignition switch:on-off-on-off-on and leave on (doing this withing a total time of 5 seocnds), then watch the check engine light to flash, pause, flash, pause, etc. Count the number of flashes, group the counts in pairs to form two digit numbers, the last of which will be 55. Then write back with the numbers for interpretation. Repeat the procedure to verify count accuracy.
Let see if we can get the car to run reliably, then work on some of the ancillary electrical problems.
Roland
P.S. I'm going on vacation for about 6 days starting Friday so if we don't get this moving in the next day, I will not be able to help till I get back.
OK, I just checked the codes 4 times. It came up 5-5 every time.
Will test the blue wire voltage tomorrow. Am I correct in assuming that the blue wire in that bundle ends up in the engine compartment, right on the wall beside the battery in a black box? That black box is near a fuse box with a cover that comes off of the top.
By the way, thanks so much for your very VERY quick response! WOW!
Duke
Answer -
Hi Duke,
I want to mention that the ignition key cylinder is not the ignition switch. Rather, the cylinder is attached by a rod to the ignition switch mounted just adjacent down the steering column. The fact that the key is removable is a lock cylinder issue, but not an electrical ignition switch issue. I believe you can get to the ignition switch without dealing with the key cylinder by removing the underside panel of th steering column if you find it to be defective. But lets not jump to conclusions about the switch.
The dark blue wire can be tested at many locations. For example it provides voltage to fuse sockets 6,7, and 8 under the dash. You will also find the diagnostic connector socket near the driver side strut tower, a 6 pin socket with only 5 wires used, one of which is dark blue trace and that should also be at 12V with the ignition switch on run.
(It is connected thru a 10 amp fuse to the dark blue wire, thus it is a dark blue trace only colored wire). You ought to hear the fuel pump hum for about 1 second whenever you turn the ignition switch to run, as you said your wife heard near the fuel tank. ASD relay shut that off until you crank the engine over and get signals from the cam and crank sensors which causes the controller to reconnect the ASD relay so as to fire up the fuel pump and the spark coil and the injectors while you are cranking. So you can verify that the ASD is closed by pulling the plug of the spark package which is a 4 pin socket, and the 12V to power the primary coils of the pack arrives there on the plug on the ddark green/black wire (you can identify that pin by holding the harness plug with the inner dimple down, and the pin inquestion is at the upper left corner of the plug in that configuration. It should be 12v of one second when you turn the key to run, then disappear but reappear when you start cranking the starter motor. If that is what you observe it means the spark signalts are o.k. and that there should be that same power going to the fuel pump and the injectors.
So that is how I would suggest checking the dark blue wire from the ignition switch. Check for the starter relay to click, in the power distribution box next to the battery.
I'm not sure what you meant by "on the wall beside the battery in a black box? It does come to a 10 amp ignition fuse in the pd box so you can check it there. That is the fuse that I mentionned above whose output wire is dark blue trace to the diagnostic connector so as long as the fuse is o.k. that connector is another place to check the dark blue supply voltage.
The 55 of course means end of readout, so you have no other fault codes at present.
The door locks and speedometer are related in that the door lock system is triggered by the speedo signal. I suspect that the flakey speedo may be due to a damaged gear on the distance sensor that is located on the top of the transaxle extension housing (the place where the half-shafts are inserted). If a mechanic pulls the right side half shaft out of the housing without first removing the speed sensor the gear on the tip will be damaged. The dealer parts counter can sell you a new gear to put on the tip of the distance sensor if that is what happened to cause your speed to be intermittant.
Roland
Thanks, Roland. I will be busy this weekend for sure. Just out of curiosity, last night at 9pm I did the code test again, and I noticed something. After the test was complete (that 5-5 code again) I heard a noise. I got out of the car and listened and found that it was coming from the gas tank area... a combination buzzing/chattering sound, almost like a FAINT running a kitchen blender with a plastic straw in it. (that's the best way I can describe it). It wouldn't stop till I turned off the ignition key, and I didn't let it run for over 30 seconds.
UPDATE: It's 2am and I tried to start the engine. Won't start. I did notice that I heard that sound again from the gas tank area, but it shut of by itself after about 20-25 seconds. Oh, I never did mention that the cruise control never worked since I had the car, for 13 years now. But I never would use it, and it's the LEAST of my worries. Roland, buddy, thanks for your help so far! You are very knowledgable!
Duke
AnswerHi Duke,
It sounds like the fuel pump, unless the sound is quite different from that of the first second after you put the switch to run. The ASD relay in the power distribution box should click on then off after a second. If it doesn't then either the contacts are sticking or the signal wire for its coil to activate/deactivate is delayed. That wire dark blue/yellow is accessible at the diagnostic connector that I mentionned earlier, so watch that wire at the diagnostic connector and listen to the ASD relay . The ASD relay is in the outer rear corner at the end of the box. The coil contacts are opposite to oneanother jumping lengthwise, while the dark blue 12V input from the ignition switch is on the outside contact next to the longer wall of the box, then it is connected to the dark green/black wire on the opposite side when the coil activates the relay contacts to close and make the connection to the dark green/black which provides power to the fuel pump, spark coil pack, injectors, and oxygen sensor.
Roland
P.S. Maybe it would be useful to you to have these specific diagrams. So drop me a postal mailing address and I'll copy and mail them to you today.
