engine/gauge wiring question

[1972BackInBlackC10]

i have done some research on this but need to double check on some things im not sure about or couldnt find info on.

i want to upgrade my dummy light cluster to a full factory gauge cluster oil,temp,amp, from what i understand all the wires for the swap are in the harness and just need to be relocated on the clip for the cluster correct? there was something about running a wire from the red wire on the alternator that im not sure where that wire goes to

second, are all the wires on the engine harness there for this cluster swap or do i need to get an engine wiring harness from a truck that had the full gauge package? any info on this or something i missed would be appreciated

thanks
mike

[MARKDTN]

You can turn a non-gage into a gage harness. You just have to move pins. I have done a few 73-87 style and at least 1 in a 67-72. I just sit down with a cluster and chase the wires. Then I sit dow with a diagram and get the colors for each function. Move the wires until they are in the correct place. Seems like there is some issue with the ammeter, but I don't remember exactly what it is. You have to have a good wiring diagram to do this.

[LockDoc]

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Here are the instructions on GMCPauls web site. Scroll down a ways.

http://www.gmcpauls.com/Tech%2520Tips1.htm

LockDoc

[1972BackInBlackC10]

thanks for the help, gmcpauls bit is one of the things i have saved and is also where im lost his article says

"You will need to replace your idiot light temp. gauge for a temp. sending unit with gauges. The black and white wire feeds from the 12gRed wire off back of alternator and requires the use of 1-4amp inline fuses, this wire you need to make and run. The black wire with brown tracer stripe you will need to make and run from the junction block to the cluster connection with a single inline 4 amp fuse approx. 6"-1' from the junction block."

im not sure what hes referring to in all this, i dont like to sound dumb but i dont know what some of these things are or where some are located

[LockDoc]

Originally Posted by 1972BackInBlackC10

thanks for the help, gmcpauls bit is one of the things i have saved and is also where im lost his article says

"You will need to replace your idiot light temp. gauge for a temp. sending unit with gauges. The black and white wire feeds from the 12gRed wire off back of alternator and requires the use of 1-4amp inline fuses, this wire you need to make and run. The black wire with brown tracer stripe you will need to make and run from the junction block to the cluster connection with a single inline 4 amp fuse approx. 6"-1' from the junction block."

im not sure what hes referring to in all this, i dont like to sound dumb but i dont know what some of these things are or where some are located

I think what he means in all of that is that you will need to replace your sending unit in the head for a sending unit for gauges, they are different. I'm guessing it should say "You will need to replace your idiot light temp. "sending" unit for a temp. sending unit "for" gauges.

The Black/White and Black/Brown wires with 4 amp fuses are for the amp gauge. You don't need them right away. Everything will work except the amp gauge. I will see if I can find a picture of them.

LockDoc

[1972BackInBlackC10]

thanks lockdoc

[VetteVet]

We discuss this subject over in the electrical forum all the time. You will have to repin the cluster plug and you will have to replace the temp gauge sender and move the wire in the cluster plug. You'll have to move the pink power wire and the gray dash lights wire too. See the diagram below for the gauge cluster wires.



Here's the wiring diagram for the ammeter wires. The fuses are circled in red and the two wires go into the cab harness to the dash plug to terminals 1 and 12. The wires are labeled blk/br in the cluster plug diagram but the engine wiring diagram shows them as black and black/white.



If you want my advice then forget the ammeter and use a voltmeter instead. It is much simpler to wire and more helpful.

[1972BackInBlackC10]

vettevet when you say id have to replace the temp gauge sender are you referring to the temp sensor on the motor? not to sound dumb but is the ammeter the gauge in the cluster?

[VetteVet]

Originally Posted by 1972BackInBlackC10

vettevet when you say id have to replace the temp gauge sender are you referring to the temp sensor on the motor? not to sound dumb but is the ammeter the gauge in the cluster?

Yes the temperature gauge sender works by resisting the flow of current to ground and is controlled by the engine coolant temperature. The hotter the engine coolant gets the less resistance to ground until the light turns on..

The difference is that the sender for the light just gets smaller until the light is turned on, and the resistance for the gauge gets less gradually, and allows the gauge to register
this as an increase in the engine temperature on a scale from cool to hot.

The ammeter also called battery gauge is on the left in the bottom row.

[1972BackInBlackC10]

thanks have it all figured out now excpet for the engine harness, i still dont know if mine will work or if i need one from a truck that has all the gauges already, im going to keep the battery gauge as i want to keep the original gauges

do you have any tips for removing the wires from the cluster plug without wrecking them