We just switched a gage panel from lights to gages and the amp gauge cought on fire! help

 

I believe it is mandatory to change the short wiring harness coming off the back of the alternator they are totally different from lights to gages.

 

Not only do you have to replace the short harness. You have to replace the main harness as well, behind the dash.

There is between 15 and 30 different circut routings between Gauges and Idiot Lights.

 

That's what I need help on so I can wire it from scratch were do the wires need to go from the dash to were and how

 

I changed the main harness behind the dash every thing works but the amp gauge cuz I don't know were the wires go from the dash

 

I changed the main wiring harness every thing works but amp gauge I need to know were to work the wires from the dash

 

You will need to go to the wrecking yard and find a 1976, 1977, 1978, or 1979 truck with Oil and ammeter gauges and take out the main wiring harness, and the altenator harness out of the donor truck. Then you will need to transplant the new harnesses into the truck you have now.

It's preferable to get a main harness the exact same year as your truck is now, but you can use a newer harness, if needed. I would not recomend a older year model harness than your 1976 because some of the features you may have now might not be supported with an older harness.

Also make sure your dash cluster matches the year model of the main wiring harness you choose.



The only other viable option is to fix your wireing harness you have now, and putting back in your Warning Lamp gauge cluster. Then you can install aftermarket gauges.

 

I changed the main wiring harness I need know were the wires go from there

 

And this Main Harness you swapped is for a truck with Gauges Correct? On the passenger side firewall with a truck with gauges there will be a plug with a Yellow/Black Wire, and a Red/Orange wire. Those are the ammeter wires from the Instrument cluster plug. The altenator wiring harness will plug into this plug, if you changed out the altenator wiring harness as well. The Altenator wiring harness is also different between gauges and warning lamps, and has to be changed at the same time.

 

Duplicate post.

 

I changed every thing and the alt stopped working so I made a new harness for the alt acording to a pic that came with the new alt my hanes manual don't show anything to help

 

It sounds like you either forgot to put a shunt between the ammeter wires and the battery wire from the altenator, or you hooked up the ammeter directly to the altenator and battery when you made your new harness.

Either scenerio above could put the full charging output of the altenator through the ammeter setting it on fire.

The Black/Red wire coming off the altenator goes directly to the battery side of the starter Solenoid.

This is how the altenator charges the battery.

Both ammeter wires hooks into the Black/Red wire, between the altenator and the battery, but between the two ammeter wires there is a shunt.

The purpose of the shunt is to alow charging current from the altenator to go direct to the battery, and alowing a smaller amount of current to go through the ammeter.

When the altenator is charging, the flow of current is to the battery directly through the shunt, but also a smaller amount of current flows through the ammeter from the altenator, to the battery, this makes the ammeter read on the charge side.

When the battery puts out more current than the altenator is sending, the flow of current is reversed. It goes through the ammeter backwards, therefore it reads a discharge.

If the shunt is missing or burned out, the full charging current from the altenator will go through the ammeter causing it to burn up.

Also the Voltage regulator is wired differently between gauges and Warning lamps.

It sounds like you need to find another altenator harness.

 

Ok that's were I need help at then how do the yel/blk and org/red wires go to in the alt loop

 

What's a shunt cuz that's the prob it sounds like

 

I mentioned this above, but I'll repeat it here.

Black/Red wire goes from Altenator Battery terminal to the battery terminal on the starter solenoid.

On the altenator side of the black/red wire is where the Yellow/black wire splices in. At this splice you will also see a Black/yellow wire that eventually will lead to the ignition switch among other things.

On the battery side of the black/red wire is where the Red/orange wire splices into. There will also be a yellow wire spliced in at this location that goes to the Altenator regulator.

Between the two splices on the Black/Red wire, for the Yellow/Black wire, and the Red/Orange wire is where the shunt goes.

As I said before, without the shunt between the two ammeter wires, the full charging current from the altenator will go through the ammeter, and cause a fire.