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Discussion Starter · #1 ·
Does anyone have a wiring diagram which details how the factory amp gauge and water temperature gauges were wired? I am attempting to install a factory gauge set (actually set up is for impala SS or caprice gauge cluster in my console).

Lighting is pretty straight forward and the oil pressure and vacuum of course are mechanical. That just leaves my "new" amp gauge and the water temperature gauge.

Amps...
I tried hooking the amp gauge up to the wires which ran to the old aftermarket amp gauge I had been running, but the gauge showed full discharge until I started the engine, then it pegged to the charge side. Should there be a resistor in this circuit somewhere?

Water temp...
I've installed a new gauge type water temp. sender and I know only one wire goes to it, does teh other pole of the gauge get +12V ?
 

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Discussion Starter · #2 ·
I finaly snapped and may have figured it out myself. Looking at the schematics for corvettes, it seems even the color code may be the same as the B body gauges I'm working with.

Looks like one lead of the Temp gauge comes directly from the temp sender, the other appears to come off the common "pink" lighting lead which powers powers door jamb switches among other things (always hot). So as I suspected here varying impedence through the ground (sender) determines signal strength (read as temp on gauge). One thing I'll have to change though, I put teflon tape on my senderbefore installing it, I bet I should remove that to keep from affecting continuity.

The leads for the amp gauge are are little more difficult to follow. One lead goes to the starter solenoid (attached to the main battery terminal) The other lead appears to go to the horn relay? Part of a rather confusing jumble of fusible links and solid leads which go to the "3" and "4" pins of the voltage regulator.
This is where I'm still a little unsure, without having the car here in front of me I can't remember how much of my factory wiring was still intact. By the time I'm done with this I may cure problems I didn't even know I had..LOL
 

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The wiring scenario that you are describing for the amp guage sounds like that for an aftermarket. Some of the factory amp guages were the parasitic type and could not be hooked up in series without showing full discharge or full charge.
 

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The 67 chevelle factory amp gauge is basically a mV gauge. It hooks up to the positive terminal tower located behind the battery (or directly to the positive battery terminal if you don't have the terminal tower on your car)and the other connection is at the horn relay where the heavy red wire from the battery connects to it. The amp gauge measures voltage drop across the 10 gauge red wire that runs from the battery to the horn relay. Hopefully you didn't damage the gauge by hooking it up to your aftermarket amp gauge wires. Turn on your lights with the car off and you should see the needle nudge towards the discharge side, if it does the opposite you need to reverse the wires at the back of the gauge. Mike M22
 

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Originally posted by m22chevy:
The 67 chevelle factory amp gauge is basically a mV gauge. It hooks up to the positive terminal tower located behind the battery (or directly to the positive battery terminal if you don't have the terminal tower on your car)and the other connection is at the horn relay where the heavy red wire from the battery connects to it. The amp gauge measures voltage drop across the 10 gauge red wire that runs from the battery to the horn relay. Hopefully you didn't damage the gauge by hooking it up to your aftermarket amp gauge wires. Turn on your lights with the car off and you should see the needle nudge towards the discharge side, if it does the opposite you need to reverse the wires at the back of the gauge. Mike M22
Mike, would that work for the 70-72 amp gauge as well? I've got the schematics for where the wires come out of the harness, however don't have the proper engine harness, and would like to wire it up?

Thanks!

Sid
 

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Discussion Starter · #7 ·
The gauges I'm using are actually from a 66 Caprice

http://www.chevelles.com/showroom/rthlc/console3.JPG

http://www.chevelles.com/showroom/rthlc/console2.JPG

I don't think I hurt the amp meter when I checked it out, I did not have the wires connected, just momentarily touched once with the engine off and once with it running. (showed full disharge/ full charge).

The schematic I'm looking at describing the fusible links came from the engine electrical section of my Chassis Service manual.
It shows two methods to wire in a guage, one for Corvette and another for the rest of us. The only significant difference is the Corvette uses a 14 ga link both up and downstream of the amp gauge.

I didn't get a chance to complete the install today but I did get another look under the hood. My engine harness has been pretty butchered over the years previous to me and I'm not sure any of the fusible links shown are still good (a couple are mia).

I did get a chance to stop by the parts hosue and get some replacement fusible links and some shrink tubing. Hopefully I will get the chance tomorrow to work on it again.
 

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If you are wiring the amp gauge like I described before I would suggest not using fusable links. Instead put inline glass fuse holders with 2 amp fuses in each. This will protect the amp gauge just fine! Sid! I don't have a wiring diagram for the 70-72 chevelle but I believe it should be the same hook-up! Try running a couple wires connected like I described to your (factory) amp gauge and see if it works !!
 

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Discussion Starter · #9 ·
Spent some time this morning and replaced my butcherd lighting harness with another I had on the shelf then installed the amp gauge using a 18 ga fusible link up and downstream of the gauge. It works great. Didn't get to the temp sender or gauge back lighting before I had to leave for work but that wiring is much simpler so I don't expect any issues. I was missing the fusible link at the + battery terminal and it looks like the one to #3 terminal of my voltage reg was bad as well. Wiring under the hood was a mismatch of wire nuts and bad splices so replacing that harness was time well spent.
 
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