Not starting

[trevcda]

I apologize for not searching thoroughly and please feel free to post links. I jumped in my 99 Tahoe this morning and it wouldn't start. Power came on and all that. The key switch interrupted power like it normally would when you start it. But there was no engagement and no turning of the starter. It did absolutely nothing. When I released the key, it returned to normally non-starting operation. I moved the shifter through all of the gears and tried starting in both PARK and NEUTRAL. I tapped on the relay in the fuse box and removed and reseated it. Still nothing. There has been no previous indication of anything being on it way out. It has started reliably for the last three years that I've owned it. It seems like a transmission shift position sensor or something.

I was rushing out the door to go to work, so didn't mess around with it for too long before grabbing another car and leaving. I know this forum has seen almost everything that could go wrong with these vehicles, so please point me in the right direction. Thanks.

 

[mizzouguy]

When you get home, turn the headlights on and see if the lights dim when you turn the key to start. If they do it can be an indication that the starter is drawing power and is just locked up/bad. If you have a helper, test to see if you have power to starter solenoid ign terminal when key is turned to start.

 

[trevcda]

No dimming on the headlights. Checked the two ignition fuses under the hood and swapped the AC and Starter relays (same model) and still nothing. No security light. No codes. It seems like there is a starter interrupt in there. I'm running out of time and ideas.

 

[mizzouguy]

Does it/did it ever have a remote start? Those can lock you out sometimes, especially if the remote was lost and the module is still in place. Those have a manual push button to reset, like a valet button. May be a possibility. If not you really have to start by seeing if there is power at the starter solenoid ign terminal and work your way backwards until you find power. Sorry maybe someone else will have another idea.

 

[about20ninj45]

Can you measure 12v at the starter? if you disconnect the starter leads and measure resistance, what do you get?

 

[God]

Go under the truck and bang on the starter solenoid a couple times , then try

 

[trevcda]

Go under the truck and bang on the starter solenoid a couple times , then try

I think you were on to something. While I didn't bang on it, I had a mobile mechanic come by who said it was brushes or something like that. He held it in the start position for about 15 seconds, let it go back to off and then back to start. Fired right up... And then died soon after. In addition to having a starter on its way out, my fuel pump decided to die at the same time. I can't win.

 

[mizzouguy]

Did you miss with the fuel pump relay or fuses when you were in the fuse box?

 

[trevcda]

Not until after the fact. I removed and reseated the fuel pump relay and checked the ECM-I fuse. I'll meter the relay socket this weekend and make sure I've got voltages where and when I should. Maybe bypass the relay to see if it's the pump or the relay.

 

[trevcda]

Never one to be afraid to admit I'm a dolt, especially if it helps somebody else, I finally have a resolution to this episode. The problem with the starter turned out to be the small wire right at the starter. I followed the mechanics advise and got a new starter for him to install the following week, but got impatient and installed it myself. Two bolts and two wires. It was fairly easy and quick. Installed and... Nothing. I was eventually able to get a helper to turn the ignition switch and found that the relay clicked, but wasn't getting anything at the starter. Traced it back a little and there is a rather clean but old break in the wire. Repaired it and it starts again!

I don't know if having them replace the fuel pump was an unfortunate coincidence or just unnecessary repairs, but there was no pressure at the check point and it didn't do it's usual two second prime when the key was turned on. In any case I have a new fuel pump and a new starter. Still, I wish that I'd been able to take all of you advise early in this thread telling me to check voltages, rather than relying on the mechanic.