67 c10 instrument panel schematic and 'terminal next to battery'

[67alldiy]

I am trying to locate where the wire that runs from the instrument panel, labeled 'terminal next to battery' runs to.

I know it runs to the fuse box then out from there. I have tracked down a loose wire, in the engine compartment, that does show connective between the two which is located, literally next to the battery and black colored.

I think this should just be connected to the ground of the battery, or a ground, at least my gut tells me this however the original owner had an inline fuse hooked up from this wire to an aftermarket cd player and my friend pulled it before I had the chance to get my eyes on it.

My dash lights do go a little crazy and after replacing turn signal switch and few other things I would like to get this figured out to put it back to original.

This is obviously an instrument panel with gauges an no dummy lights.

[GMCPaul]

There is a junction block that should be attached to passenger side fender that looks like this

The wire from dash connects to it, a fusible link then comes off battery on positive and connects to this junction block, and the 12V positive wire coming from alternator also connects to it.
Here's the wiring diagram for it.

Paul Jr @ GMCPauls

[67alldiy]

Thank you so much. Can you tell me what exactly this powers and controls?

[67alldiy]

Can you also tell me what size fuse should I be using for the fusible link and the size of the inline fuse from the wire that connects from the dash to the junction box?

Thanks in advance.

[GMCPaul]

Here's a image from our Tips page of our website depicting the instrument panel connections for a gauge dash cluster. You'll see that the #12 Blk/Brn wire "Terminal by battery wire" uses a 4 amp fuse which I believe is located about 12"-18" from the junction block it connects to near the battery, the opposite wire at instrument cluster serving this circuit is the #1 Alternator wire. The purpose of these 2 wires is to show a charge or discharge indication for your alternator gauge.

[67alldiy]

Thank You So Much

[GMCPaul]

Fusible link size depicted in wiring diagram I posted above and it shows 16ga, which would stand to reason because the standard for AWG wire sizes (wire gauges), is each fusible link used should be 4 wire gauge sizes smaller than the wire it is designed to protect. For example: to protect a 12 gauge wire, use a 16 gauge link. If you'll look at the wiring diagram you'll see the red wire coming into to junction block from Alt. is 12ga, and thus GM used a 16ga wire as fusible link size to protect the charging circuit between alternator and battery.

[GMCPaul]

Your more than welcome, Have a nice weekend.
Paul Jr @ GMCPauls

[67alldiy]

follow up
After setting this up like you said I am actually blowing the fusible link(inline fuse) from the battery to the junction box. I should have mentioned that I am running an alternator and not sure if this does make a difference.

Before installing the fusible link my truck at least ran however when I put the lights on and press the break the car dies and the fusible link burns up.

Could this be due to a bad ground? I wouldn't think the break switch could cause this.

All fuses have been checked and replaced, new alternator, new turn signal switch, new hi/low beam switch,
old brake pedal switch

thanks in advance.

[67alldiy]

start with the easiest thing first

so might have answered my own question. It seems that there needs to be a straight quality hot wire running straight from the alternator to the battery, maybe junction box?

I believe an alternator puts out around 100amps so any typical inline fuse would easily blow

will test this theory tomorrow

[dmjlambert]

Your fusible link wire burns up to protect the 12 gauge wire. There are circuits in the truck that do not have fuse protection at all. The headlight wiring is not fused. So I think you found the problem. Check the headlight switch, and the headlight wiring between the blue wire at the headlight switch all the way to the headlights. Look especially close at the dimmer switch and its wiring under the carpet/mat. And the wiring that goes to the headlights goes through the driver-side fender. Mine was eaten by rats inside the fender. I disconnected the plug at the firewall and pulled it through the fender to the driver-side headlight area, and patched it up with some soldered-in wire sections, and covered up my patches with heat-shrink tubing, and re-wrapped the wiring, and put it back through the fender and plugged in the connector again. Use an ohm meter or continuity checker to do some testing.

Here is the full wiring diagram:

http://67-72chevytrucks.com/vboard/s...&postcount=302

[67alldiy]

thanks for the help

I actually have two headlight switches and tested both and the same symptoms are there.

I have now also replaced the brake switch.

What I am down to now

Car runs and shuts off fine, one time the dash lights and running lights came on . applied the break and everything shut off

I have checked the headlight switch and am only getting power to the head lights. I do have a 12v and good ground.

I get no parking, dash, dome AND brakes/rear running lights

******
Tail Stop, Dome, Park
When checking for voltage from both sides of the fuse under dash it actually sparks and burns up the fuse. Almost as if one side is grounded. When checking connectivity with ground, that same side does show connectivity?

I do have a good 12v side(left side), just wont transfer through the fuse like the others(checked all others and they were good)

New Turn signal, fuses, brake switch, tested headlight switch

Any help is appreciated

[dmjlambert]

Originally Posted by 67alldiy

When checking connectivity with ground, that same side does show connectivity?

Is this a question? Or are you telling that you have a wire that connects to ground?

If you have continuity to ground on a wire, you need to fix that. You may have the insulation on part of the wire worn off, eaten, or deteriorated, and touching the body of the truck. Remove light bulbs and disconnect plugs when checking for continuity or shorts to ground. Suppose you have a wire that goes to the tail light at the back of the truck, and you have the bulb removed and the wire unplugged. If you have continuity to ground on that wire, you need to examine the wire. My tail light wire that runs from near the gas pedal where it leaves the cab and goes under the truck was also partially eaten by rats where it goes up over the rear axle, so I had to solder-splice in repair sections. It was shorting to ground.

[67alldiy]

start with the easy things first

after stepping back I went and tested the original signal switch and it finally kicked my lights on (no more burned fuses)

summit racing sent me the wrong part. even more reason to really take your time and ask questions. summit had 4 different part numbers for my truck

advance and o'reilys had a few in stock and found the right part

my brake lights and headlights are working however I still do not have dome and rear running lights

checking grounds and schematics .

lesson learned