Mechanics

97 WONT START AND NO DASH LIGHTS?

1997 Pontiac Sunfire • 4 cylinder FWD Automatic • 151,000 miles

I just replaced my fan motor last night. It started and ran fine. I went out today and as soon as it started to crank everything went dead. The interior lights and horn etc work and when I put the key in it dings like normal but nothing happens when I turn the switch. No clock on the radio and no lights on the cluster. I checked all fuses in the panel and under the hood. Any thoughts?
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Doug2060
August 1, 2011.




When you replaced the "fan motor" are you referring to the radiator fan or the fan in the dash that blow the air out your vents? Why did you replace the fan motor? Have you tried a jump start to rule out a weak battery?

Tiny
Danlesabre
Aug 1, 2011.
I replaced the radiator fan motor. It wasn't coming on when hot or when AC was on. I could smack the back of the fan motor and it would come on for a few minutes then die again. After replacing it the new motor worked perfectly. The original motor had become weak over the past few weeks and I briefly had it straight wired to the ignition at the wiper fuse as the temperature was slightly higher than usual at times. I reconnected it properly 3 days ago. I didn't notice it had become weak until using the new motor and seeing how much more powerful it was. I checked the fuse panel where it was connected and found no damage. All the fuses are fine and getting power when tested with didital multi meter. I do not have a good wiring diagram but I am getting power at the wires going to the ignition switch. The battery is good. I even tested with another battery from my moms 02 Cavalier.

Tiny
Doug2060
Aug 1, 2011.
I just replaced the ignition switch with no luck.
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Tiny
Doug2060
Aug 1, 2011.
What is the problem you are experiencing? No electrical power anywhere in the car, or the engine won't start?

Tiny
Danlesabre
Aug 2, 2011.
Both. The battery is fine. The interior lights come on and the horn will blow. The headlights and emergency flashers will also come on but nothing else. When I turn the key nothing happens. No lights on the instrument cluster or anything.

Tiny
Doug2060
Aug 2, 2011.
Have you checked all the fuses under the hood? There may be some with a plastic cover over them that you can not use your multi meter to check so you have to look very closely to see if there is an open circuit. Also try swapping relays around, don't mix and match relays either, just switch identical parts and see if that changes anything. Also, have you performed any recent work? Could any wires have been crushed? Do you know where the starter relay is? Have a helper go inside car and cycle the key from start to off repetitively, if you go under the hood you should be able to hear the starter relay click and feel it move if you put your fingers on it. Let me know what you find.

Tiny
Danlesabre
Aug 2, 2011.
Thank you. I did all that. There is no power coming from the ignition to the starter relay. I have tested every fuse, relay, and fusible link. Even the ones that have nothing to do with the problem. The fan motor is the only recent work I've done on the car. I tested everything in that area including testing the starter. My multi meter picks up power going to the ignition switch but still nothing. The PCM is getting power also. I can't even scan for codes. When I put the key in the ignition I get the usual dings but when I turn absolutely nothing happens. There is no voltage drop on the battery when the ignition is turned to start either.

There is some additional information I feel I should share. 3 weeks ago the theft system light came on but when I turned the car off and back on it went away. It never happened again. The theft light would come on when turning to ignition on sometimes but once I started the car it immediately went off just like the check engine and ABS lights do. It never did this before that. I can also confirm that the fan relay does not recieve a signal from the PCM to start the fan when it's hot. I have had to leave the AC on and it would stay on like it should with the AC. The temperature sending unit was replaced twice before tracking down the wire from the PCM to confirm no signal was being sent despite the sending unit working properly. This problem has existed since February. The car has a salvage title and was involved in a front end collision several years ago. I have opened all the main wiring harness sections especially along the front of the car but find no damaged wiring. Other than the fan issue the car ran great and just hit 150,000 miles.

Tiny
Doug2060
Aug 2, 2011.
You mentioned that you can not scan for codes? Do you have a scanner/code reader that you are using? Does your device communicate with the car's computer at all?

Tiny
Danlesabre
Aug 2, 2011.
When I plug it in, it says connected but when I hit read it says unable to scan and tells me to make sure the key is turned to on etc.

Tiny
Doug2060
Aug 2, 2011.
I also just noticed something. Using my multimeter I can probe into the yellow wire of the ignition switch which goes out to the starter. When I turn the key like I'm going to crank it, it reads 0.14 volts. I was expecting to get no reading at all.

Tiny
Doug2060
Aug 2, 2011.

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