Hi Guys,
PART ONE: I have my 72 Demon dash on the bench. I am installing Autometer gauges. These will include speedometer, tachometer (with MSD 6AL), oil pressure, temperature, volt meter, and fuel gauge. So I installed the gauges into a new plastic dash insert to hold them in place. I noticed there was no place for directional signals and high beam light, so I purchased small LED lights with chrome bezels and drilled holes for them. I then picked up rolls of 18G wire to match the colors of the stock wires which went to the original printed circuit instrument cluster by way of the round plug with all the prongs. I cut the round plug off the harness and using 3M brand crimp and heat seal connectors I added a couple feet of the same color wire to each wire and labeled them to where they go. Next I needed to wire the gauges lighting so they would function when the light switch is pulled on. The gauges I bought were the LED gauges which have nice plug spade terminals on the backs for easy on off connections. Basically, the lighting side is only a 12v feed and a ground. So I took the Orange (instrument lamp) wire and ran it to the positive side of all the gauges led lights. I bought what is called piggy back push on spade connectors in the 3M brand which have the crimp and heat melt insulation. These piggy back connectors allow me to just jump from one gauge to the next and also give me the ability to be able to just pull one gauge and unplug it if it needs service at a later time. So this should take care of all the lights when the parking/headlight switch is pulled on. That was easy LOL.
PART TWO:
Next I needed to wire each gauge to its corresponding color wire from the round plug I cut from the original harness. They are as follows.
a. TEMP GAUGE: Simply take the Violet wire and run it to the Instrument terminal on the back of the gauge. I used again the 3M connectors with the crimp and heat melt insulation. I keep saying this as it makes it easy to unplug them and the heat melt insulation makes for a very nice tight connection plus the 3M ones are made of much better, thicker material and the insulation melts real tight to the wires. Don't use the cheap crap made in China they sell everywhere. I got mine from a place called Dell City and also from Grainger.
b. OIL PRESSURE GAUGE: Simply take the Gray wire and run it to the Instrument Terminal on the back of the gauge using the same connectors.
c. FUEL GAUGE: The fuel gauge would be the Dark Blue wire, which would also connect to the Instrument terminal on the fuel gauge. This was a little tricky because I found out the LED AutoMeter gauges I bought with the LED lights did not come in the correct ohm range to properly work with my fuel sending unit. So, I had to change that one gauge and buy the same gauge with the same looking bezel and printing, but it only came in the standard light bulb type. So unless you get all standard gauges, the lighting will be different. So what I did was to use the red/orange light bulb cover on that one gauge and it will just glow with a red/orange tint to indicate fuel. My mistake, but I think it will look OK.
d. VOLT METER GAUGE; This is another tricky one: To eliminate the AMP GAUGE, I simply took the 12G black and 12G red amp wires and soldered them together real good so there will never be any heat buildup under the dash. I then covered the solder with the heat melt tape and then some friction tape for a permanent tight connection. So, now the new VOLTMETER needs a keyed 12V source, but so do all the previous gauges above. So this is where the DARK BLUE w/WHITE TRACE comes in. Using the same 3M piggy back connectors, you can run the wire to the 12V side of the VOLTMETER gauge and then jump from there to the next gauge which in the end would give you a 12V ignition keyed circuit so when the key is off, there is no power drawer to any of the gauges.
e: SPEEDOMETER: This gauge comes with a sending unit that screws onto the connection on the tranny and because this is going from a mechanical to an electrical pulse, I will be running a 12V feed off one of the piggy back gauges and then down to the sending unit.
f: TACHOMETER: Same as the SPEEDOMER in that I will be running the 12V to the MSD BOX.
G BRAKE LIGHT: This was the little LED red light I drilled into the dash. This simply gets spliced 20G Black wire.
H: HIGH BEAM INDICATOR: again a small BLUE LED light which I spliced to the 18G RED wire.
I: TURN SIGNAL INDICATORS: I used two green LED lamps and these get wired to LIGHT GREEN 18G wire for the left and TAN 18G for the right.
J: INSTRUMENT GROUNDS: Now all of these instrument gauges need to now have a ground wire. You can again take the piggy back 3M terminals and jump from one gauge to the next to make up the ground side in which then I can ground it to a good ground probably in or under the dash side mounting bolt.
At any rate, This is what I so far have done. I will post a few pictures in a day or two. But, not being an electrical minded person, I wanted to share this with others, as I have searched for a topic like this and have not found one anywhere. If there is anything that anybody sees here that looks as though it will be an issue or will not work, please chime in here as I am an amateur and can use all the advice I can get. Pictures to follow. But my goal was to be able to isolate and remove any instrument gauge by just unplugging it and this is what I came up with.....
PART ONE: I have my 72 Demon dash on the bench. I am installing Autometer gauges. These will include speedometer, tachometer (with MSD 6AL), oil pressure, temperature, volt meter, and fuel gauge. So I installed the gauges into a new plastic dash insert to hold them in place. I noticed there was no place for directional signals and high beam light, so I purchased small LED lights with chrome bezels and drilled holes for them. I then picked up rolls of 18G wire to match the colors of the stock wires which went to the original printed circuit instrument cluster by way of the round plug with all the prongs. I cut the round plug off the harness and using 3M brand crimp and heat seal connectors I added a couple feet of the same color wire to each wire and labeled them to where they go. Next I needed to wire the gauges lighting so they would function when the light switch is pulled on. The gauges I bought were the LED gauges which have nice plug spade terminals on the backs for easy on off connections. Basically, the lighting side is only a 12v feed and a ground. So I took the Orange (instrument lamp) wire and ran it to the positive side of all the gauges led lights. I bought what is called piggy back push on spade connectors in the 3M brand which have the crimp and heat melt insulation. These piggy back connectors allow me to just jump from one gauge to the next and also give me the ability to be able to just pull one gauge and unplug it if it needs service at a later time. So this should take care of all the lights when the parking/headlight switch is pulled on. That was easy LOL.
PART TWO:
Next I needed to wire each gauge to its corresponding color wire from the round plug I cut from the original harness. They are as follows.
a. TEMP GAUGE: Simply take the Violet wire and run it to the Instrument terminal on the back of the gauge. I used again the 3M connectors with the crimp and heat melt insulation. I keep saying this as it makes it easy to unplug them and the heat melt insulation makes for a very nice tight connection plus the 3M ones are made of much better, thicker material and the insulation melts real tight to the wires. Don't use the cheap crap made in China they sell everywhere. I got mine from a place called Dell City and also from Grainger.
b. OIL PRESSURE GAUGE: Simply take the Gray wire and run it to the Instrument Terminal on the back of the gauge using the same connectors.
c. FUEL GAUGE: The fuel gauge would be the Dark Blue wire, which would also connect to the Instrument terminal on the fuel gauge. This was a little tricky because I found out the LED AutoMeter gauges I bought with the LED lights did not come in the correct ohm range to properly work with my fuel sending unit. So, I had to change that one gauge and buy the same gauge with the same looking bezel and printing, but it only came in the standard light bulb type. So unless you get all standard gauges, the lighting will be different. So what I did was to use the red/orange light bulb cover on that one gauge and it will just glow with a red/orange tint to indicate fuel. My mistake, but I think it will look OK.
d. VOLT METER GAUGE; This is another tricky one: To eliminate the AMP GAUGE, I simply took the 12G black and 12G red amp wires and soldered them together real good so there will never be any heat buildup under the dash. I then covered the solder with the heat melt tape and then some friction tape for a permanent tight connection. So, now the new VOLTMETER needs a keyed 12V source, but so do all the previous gauges above. So this is where the DARK BLUE w/WHITE TRACE comes in. Using the same 3M piggy back connectors, you can run the wire to the 12V side of the VOLTMETER gauge and then jump from there to the next gauge which in the end would give you a 12V ignition keyed circuit so when the key is off, there is no power drawer to any of the gauges.
e: SPEEDOMETER: This gauge comes with a sending unit that screws onto the connection on the tranny and because this is going from a mechanical to an electrical pulse, I will be running a 12V feed off one of the piggy back gauges and then down to the sending unit.
f: TACHOMETER: Same as the SPEEDOMER in that I will be running the 12V to the MSD BOX.
G BRAKE LIGHT: This was the little LED red light I drilled into the dash. This simply gets spliced 20G Black wire.
H: HIGH BEAM INDICATOR: again a small BLUE LED light which I spliced to the 18G RED wire.
I: TURN SIGNAL INDICATORS: I used two green LED lamps and these get wired to LIGHT GREEN 18G wire for the left and TAN 18G for the right.
J: INSTRUMENT GROUNDS: Now all of these instrument gauges need to now have a ground wire. You can again take the piggy back 3M terminals and jump from one gauge to the next to make up the ground side in which then I can ground it to a good ground probably in or under the dash side mounting bolt.
At any rate, This is what I so far have done. I will post a few pictures in a day or two. But, not being an electrical minded person, I wanted to share this with others, as I have searched for a topic like this and have not found one anywhere. If there is anything that anybody sees here that looks as though it will be an issue or will not work, please chime in here as I am an amateur and can use all the advice I can get. Pictures to follow. But my goal was to be able to isolate and remove any instrument gauge by just unplugging it and this is what I came up with.....
