Steering Column Repair: Electrical scamatic for 1984 Chevy S10 diesel Pick-up, chevy s10, scamatic

Question
Hi Doug,
My husband and I have a 1984 Chevy 6.2L diesel pick-up and we are having problems finding a direct ground that keeps blowing the 20amp fuse for the dash gages. We have tried unsuccessfully to find an electrical manual to help us trouble shoot this problem. When we turn the lights on at night we get a high pitched squeal and when the lights are on dim we get the bright lights indicator. We could really use some help in this area.

Thank you.

Answer
Hi Donna:
I hope I can help you, but trouble shooting electrical shorts is quite difficult over the internet...but we'll try.
Is the squeel coming from under the hood?  It may be your alternator making that noise.  Sometimes the diodes inside make a squeeling sound when there is a draw on the system.  But we'll come back to that.  Don't replace it just yet.
The cross connection in the instruments tells me there is not a good ground connection, so the power is looking for a way to bet back to the battery.  That's all any circuit is.  You send power to the appliance and the ground circuit allows it go back.  I would check the ground from the battery to the body.  You should have a 10 gauge wire (small cable) as well as the large cable coming off the negative side of the battery.  the large on should go directly to a bracket on the engine and the small on should be attached to the body.  Those are both ground cables.
check to see if there is also a good strap near the back of the engine attached from the engine to the body as well...another ground strap.
If any of those are rusty or loose, it will do what you are talking about.  You are missing a good ground into the cluster and they all stem from the battery and body.
once you repair the ground connection, the diodes in the alternator should quiet down.
I hope this helps.  It's about all I can offer from here
Good luck

Doug