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Buzzing/hum from cluster, won't start.

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Old 04-19-2012, 10:06 AM
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It might be time to take the cover off of your relay and check voltages and ground resistance. You'll find that the relay has 12V available from the battery constantly, ready to supply the fuel pump whenever the relay closes. You can push the contacts together and should hear the pump run. From memory, the terminals would be 30 for the 12V, and 31 for ground. Use a DVM to check the ground at that terminal to the battery negative post- it should be very low resistance. Then when attempting to start, see if you can measure the voltage at the relay coil's "+" terminal, which is coming from the ignition switch. It should be whatever the cranking voltage happens to be, say around 10V. Sorry but I've got to look at the schematic to see which relay terminal that is.
Old 04-19-2012, 03:50 PM
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Another update.. Tried tapping starter and solenoid with rubber mallet.. nothing. Unbolted positive contact on solenoid and cleaned up the connections with dremel tool and wire brush until it was shiny again.. No cigar. I then ran a wire directly from the positive on my battery to the positive connection on the starter.. starter doesn't move even with ignition on. So finally I checked to see if there was power on the starter itself.. I put the negative lead from my multimeter directly on my negative terminal on my battery and then the positive lead on my starter positive.. I have 12.65 volts down there. Plenty of power to turn over a starter. So I'm beginning to believe either my starter or solenoid is kaput. :/
Old 04-19-2012, 05:23 PM
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Now check the solenoid resistance; if it shorted to ground, then that could explain the motor not running, and the buzzing of the fuel pump relay from low voltage. I would expect the ignition contacts would be badly burned if that was the case though. I don't know what the normal solenoid resistance is supposed to be, probably only a few Ohms.

So if you jumper between the large battery cable at the solenoid, and the small terminal for the coil next to it, nothing happens?
Old 04-20-2012, 03:46 AM
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I had not tried that. I will try crossing the solenoid tomorrow morning, I cannot tonight because I have to work. Do you mean jump where the battery cable bolts up to it and the other terminal that has a short copper braided line? I can't Imagine you mean where the plastic clip plugs in.. Also it may be worth noting that I can start the car, but only by bump starting..
Old 04-20-2012, 08:01 AM
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I do mean where the small wire plugs on. If you jump to the short braided one, the motor should run (without engaging the ring gear) but I don't like bright sparks under the car! Jumping to the small terminal from the battery cable only bypasses the ignition switch's starter circuit, so you can determine if the problem exists right at the starter motor.
Old 04-20-2012, 08:52 AM
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Alright, I will check that as soon as I get a chance tomorrow morning, thanks for your help!
Old 04-20-2012, 08:57 AM
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Also.. I have been searching for a DIY for removing my starter.. All I have found is for the 12v. I have a 30v. What's the easiest way to attack this if I have to remove it? Or do you know of a DIY I could follow?
Old 04-20-2012, 10:27 AM
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Remove alternator. Remove starter.

Personally, I would not touch the starter until I at least tested with new ignition switch and verified that the starter was properly grounded.

Starter failure is very rare.
Old 04-21-2012, 08:58 AM
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Well my starter is fine.. I was able to jump it to the terminal that plugs into the plastic clip. It turns over like it should. I also tried pulling apart my steering column again and turning the Ignition switch over with a screwdriver and still nothing. I tried this thinking maybe the ignition switch didn't turn far enough with a key in the ignition barrel. But anyways.. could this still be my ignition switch? everything else in the car powers up as normal when I turn the key on. Also.. does the starter in my car have a fusible link? I have a 30v AHA just to clear things up.
Old 04-21-2012, 09:22 AM
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That small solenoid wire with the push-on clip goes right up to the ignition switch, but first through a "bridge connection" on the relay panel (4th from left), in place of the transmission relay that would be there if your car was an automatic. From there the wire goes right to the ignition switch, terminal 50 (red/black wire on my '96). So if you pull the ignition switch connector off the switch, and apply 12V current to that wire, the starter should run. If it does, that pretty much verifies the ignition switch as being at fault.


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