wiring diagram for a dash with gages

[68 longbed]

Does anyone have a wiring diagram for agage dash? I've searched every where and haven't found one. I really need it to trouble shoot an alternator problem.

[jugernot]

I have an adobe reader master diagram that another member made. But I don't know how to post it. Send me a PM with your email and I will email it to you.

[72lb4x4]

How did you get to the dash with an alternator problem?

[68 longbed]

Originally Posted by 72lb4x4

How did you get to the dash with an alternator problem?

I changed from a idiot light dash to gages following faq on this board. when you remove the brown wire as instructed you lose field voltage.

[Huck]

Board vendor---GMC Paul had the conversion directions on his website. Huck

[68 longbed]

Originally Posted by Huck

Board vendor---GMC Paul had the conversion directions on his website. Huck

This is the same directions I followed. Does not say where to hook the brown wire which is the feild wire for exciting the alternator. Also jugernut pm was sent

[68 longbed]

ttt

[70 Suburban]

brown goes to pin 25 on dash plug.

[VetteVet]

Not to be a wisea$$ but there are only 12 pins on the plug and the diagram shows the brown wire on the no. 8 plug on the idiot light dash gauge.





Have you converted to an internal regulated alternator? If so you will need to run a wire to the alternator to replace the brown wire in order to excite the regulator and it will have to have a resistor in it to simulate the idiot light. This wire can be run from anywhere that is a keyed on source except the ignition coil, and the resistor value is 75 ohms and 3 watts.
You could use the brown wire off pin no. 8 and connect it to the fuse box to a keyed hot terminal, then hook the engine side to the resistor then to the alternator.
If you want to run the battery guage then you will have to run the two black wires with the 4 amp fuses as specified in GMC Pauls FAQ.
Here is a diagram showing the two wires on the engine side of the firewall.
One is on the top and connects to the fender junction block and the other is on the bottom and connects to the three-way red circuit. I think I would just replace the battery gauge with a volt gauge and wire it accordingly.

[68 longbed]

Originally Posted by VetteVet

Not to be a wisea$$ but there are only 12 pins on the plug and the diagram shows the brown wire on the no. 8 plug on the idiot light dash gauge.

Attachment 431939

Attachment 431940

Have you converted to an internal regulated alternator? If so you will need to run a wire to the alternator to replace the brown wire in order to excite the regulator and it will have to have a resistor in it to simulate the idiot light. This wire can be run from anywhere that is a keyed on source except the ignition coil, and the resistor value is 75 ohms and 3 watts.
You could use the brown wire off pin no. 8 and connect it to the fuse box to a keyed hot terminal, then hook the engine side to the resistor then to the alternator.
If you want to run the battery guage then you will have to run the two black wires with the 4 amp fuses as specified in GMC Pauls FAQ.
Here is a diagram showing the two wires on the engine side of the firewall.
One is on the top and connects to the fender junction block and the other is on the bottom and connects to the three-way red circuit. I think I would just replace the battery gauge with a volt gauge and wire it accordingly.

Attachment 431942

Yes I have converted to internal regulator would love a volt gauge if it looked factory and took place of ampmeter.

[70 Suburban]

I got that out of the Factory service manual its not 25 pin its location 25. ill post the page from the assembly manual when i get home