Need help.... Please!!!!

[travo87]

So I have a 95 Yukon SLT 4x4 4 door it's got 217500 miles on it so it's been around the block. Well when I first got it it wouldn't start.... Long story short I replaced the pickup coil plugs wires and even the ignition control module and finally that was it it started well now that the starter ate my flex plate I am in the middle of changing that out. But my issue is that whenever I go to start it the voltage reads 10 volts on the indicator gage in the truck even when I take my volt meter and put the positive on the battery and the negative any where on the truck but when I put the negative on the negative side of the battery it reads 12.5 volts. So when I try to start it there isn't no starter movement at all it just makes the car go hay wire like there is a short somewhere but sometimes I can get the starter to turn the engine over but then it goes back to the same old thing no click no start I've looked every where for a short by taking out the dash and the main wiring harness and looking them over nothing. But there is one relay the fuel pump relay that when I leave the key on and mess with the relay the voltage indicator and dash lights get dimmer and then brighter and flicker anyone have any ideas or am I just better off using some tannerite on this thing

 

[travo87]

Also where can I get wiring diagrams off the internet for free

 

[wjburken]

Did you replace the starter after it took out your flex plate? If not, have you tested the actual starter? How did it take out your flex plate? Good working starters don’t normally ruin flex plates. Before I started digging into all the wiring, I’d take the starter out and bench test it or take it to Autozone and have them test it. My first step, if it was in my driveway, would be to see if the starter is bad and is drawing down voltage trying to turn and causing issues due to low voltage.

 

[Marky Dissod]

GM is notorious for using very thin wires in places where they'd get away with it til after the warranty expires.
Last year I had weird starting issues, despite the batt & alt testing strong.
If the steering wheel were tilted down, it wouldn't start, unless / until I raised the steering wheel to the top.

Haven't yet got round to fixing it, but I always start it with the steering wheel raised up now.

 

[Eman85]

Put your voltmeter on the battery, fully charges should read 12.6V. If you put the negative lead of the voltmeter on the engine and it doesn't read the same as when you put it on the battery you have corrosion at the connections. Remove the cables and thoroughly clean BOTH ends. As far as the dash goes that is an indicator, not a gauge don't expect accuracy on a 28yo dash.

 

[east302]

Also where can I get wiring diagrams off the internet for free

PDF copies of the GM service manuals can be downloaded here:

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

 

[exp500]

Battery Cables are a suspect also.

 

[j91z28d1]

Battery Cables are a suspect also.

this.. just replace both of them, sounds like a bad ground cable, but just so both. it's worth it.

by that I mean from battery terminal to where ever it bolts to. plus you have side posts which are always a hassle. they probably aren't making a good connection there.

 

[Hoesgottaeat2]

I second the motion for attention to the battery cables. This vintage of cable, in particular the dual layer positive terminal is a known culprit at this age.

 

[travo87]

Did you replace the starter after it took out your flex plate? If not, have you tested the actual starter? How did it take out your flex plate? Good working starters don’t normally ruin flex plates. Before I started digging into all the wiring, I’d take the starter out and bench test it or take it to Autozone and have them test it. My first step, if it was in my driveway, would be to see if the starter is bad and is drawing down voltage trying to turn and causing issues due to low voltage.

Yes it's a new starter and I also took to to orielys and had it tested but the worrd thing is is if I put my flashers on and turn on the key it goes hay wire like the tech starts working and the speedo goes up to 25 mph and the car isn't even running and makes weird noises could it be front the stereo wires somewhere grounding out