Shops, Barns, Varmints, and Trucks

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Need help 99 GMC

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Forum Name: Shops, Barns, Varmints, and Trucks
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=151960
Printed Date: 20 Aug 2025 at 9:51pm
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Topic: Need help 99 GMC

Posted By: Tracy Martin TN
Subject: Need help 99 GMC
Date Posted: 09 Jul 2018 at 9:30pm

My truck won't start. Dash lights and all work. Will not even click starter. Did this a month or two ago. I used other key and it started right up. Does have the security system on it. It acts like it doesn't recognize the key. What is most likely culprit? Thanks, Tracy

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No greater gift than healthy grandkids!

Replies:

Posted By: Tracy Martin TN
Date Posted: 09 Jul 2018 at 11:24pm

My truck is at farm. Had to get Hannah to come pick me up. Hopefully someone will know what is wrong. Any help appreciated. Thanks Tracy

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No greater gift than healthy grandkids!

Posted By: Dakota Dave
Date Posted: 09 Jul 2018 at 11:37pm

If the security system locks you out it'll still crank but not start and the security light will be on. You can reset it by turning it to run and leave it there for 10 minutes don't try start. Turn key off to lock for 10 seconds and back on for 10 minutes of for 10 seconds and on to start. But if it's not cranking first place I'd look is test light to starter soloniod. Should have power continuously to the big lug and power to the small lug when key is it start position.

Posted By: bobkyllo
Date Posted: 10 Jul 2018 at 12:28am

Dave is correct with the starter. I have seen the key switch go bad in that era pickup often though. But start with the starter first.

Posted By: Tracy Martin TN
Date Posted: 10 Jul 2018 at 8:01am

Can I jump start across solenoid in this condition to get it to a shop? Thanks Tracy

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No greater gift than healthy grandkids!

Posted By: jaybmiller
Date Posted: 10 Jul 2018 at 8:07am

I'd doubt it...

IF the security system was properly programmed, it'd kill power to the fuel pump and the coils,both are electrically controlled by the 'computer'.

Mind you what it really does is anybody's guess.

try it, see what happens, just be careful of sparks.

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3 D-14s,A-C forklift, B-112
Kubota BX23S lil' TOOT( The Other Orange Tractor)

Never burn your bridges, unless you can walk on water

Posted By: fixer1958
Date Posted: 10 Jul 2018 at 8:52am

Why not. It will either start or it won't.

If it cranks and not start that's one clue eliminated.

If it won't crank at all it's the starter or a power/ground issue.

Posted By: Dakota Dave
Date Posted: 10 Jul 2018 at 9:05am

The pass lock system has nothing to do with won't crank. It just shuts down the power to ignition. No ignition no fuel no start it'll crank till the battery goes dead. If it was the pass lock the security light comes back on after you start cranking the engine. Turn the key on and jump the starter solenoid. If it turns over it'll start. If it dosent wack it a couple times and try again. If you can get help have them hold the key in the start position and wack it. Then take it to the shop and change the starter.

Posted By: Coke-in-MN
Date Posted: 10 Jul 2018 at 9:30am

The starter solonoid does not have a separate ground like old systems do but grounds through starter brushes - So you will not get the clicking of the starter solonoid or the pull in of drive one is use to hearing in older vehicles .
The starter brushes are held onto a plastic holder which if brushes are worn down the plastic will hit armature first and prevent engagement of solonoid circuit . It might be intermittent and sometimes wrappin on starter will allow it to work - until next time - or a dead starter is the outcome .
Sometimes a worn starter bushing in end cap will cause the armature to move enough to cause the problem . Replacing the end plate and new brushes should solve the problem

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Life lesson: If you’re being chased by a lion, you’re on a horse, to the left of you is a giraffe and on the right is a unicorn, what do you do? You stop drinking and get off the carousel.

Posted By: Tracy Martin TN
Date Posted: 10 Jul 2018 at 10:06am

Just so everyone is on same page....... truck would not crank over or start. Dash lights, bells and buzzers all worked. Never done this exact thing before. I don't think I have ever replaced starter, but not for sure. Checked and cleaned battery terminals before coming home last night. I will rap on stater and see if that helps tonight. Hopefully something simple to fix. Thanks for the help, and more is welcome also. Tracy

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No greater gift than healthy grandkids!

Posted By: HD6GTOM
Date Posted: 10 Jul 2018 at 3:09pm

Tracy from experience running a shop. If it is the starter, either take yours to a reputable rebuilder or buy a new one. I have seen way too many of the rebuilt ones fail way too soon.

Posted By: Tracy Martin TN
Date Posted: 10 Jul 2018 at 8:13pm

Got to farm, put the key in, turned it nothing. Did it a second time and it started right up. Have stopped and started it several times. Can't tell any thing ever happened. Hope it doesn't strand me somewhere.If it happens again, maybe I can pinpoint the exact problem. Thanks for all the help. Any suggestions welcome. Tracy

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No greater gift than healthy grandkids!

Posted By: jaybmiller
Date Posted: 10 Jul 2018 at 8:53pm

I'm thinking either bad(gimpy) ignition switch or gear shift PRNDL switch.

It's common they just wear out, or get misaligned and not make proper electrical contact, so a little jiggling here or there and 'magically' it works....

When you think about the use/abuse switches take year round, well anything that old SHOULD have failed by now !

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3 D-14s,A-C forklift, B-112
Kubota BX23S lil' TOOT( The Other Orange Tractor)

Never burn your bridges, unless you can walk on water

Posted By: tadams(OH)
Date Posted: 11 Jul 2018 at 1:43pm

Yes I would check the safety switches

Posted By: Steve M Ind
Date Posted: 12 Jul 2018 at 7:50am

With the key turned to the run position the "security" light should come on then go out in a few seconds. If it stays on or flashes then you have a security problem. Most common security problem is the pass key sensor located in the steering column.