Idiot Light to Gauges Conversion

Can't remember if this has been discussed here, but has anyone done the dash cluster idiot light to gauges conversion on a Chevelle/Malibu/Monte Carlo? I know the flex circuitry behind the two styles of clusters is different...but, does it require replacing the entire underdash and engine bay wiring harnesses? I also know there is a separate pigtail wire out to the engine for the tach. Question came up over the weekend and would appreciate any info.

Wow...that's a whole lotta splicing. I think I'd be inclined to just find a complete wiring harness designed for tach gauge cluster and save myself alot of headaches.

Mcarlo77 wrote:Wow...that's a whole lotta splicing. I think I'd be inclined to just find a complete wiring harness designed for tach gauge cluster and save myself alot of headaches.

i did it to my 73. i had the gauges and the under dash harness. i bought an NOS engine harness off ebay and took a weekend and did it.

So...aside from the special Tach wire that runs out to the distributor, you DO need a different engine bay harness?

i bought the NOS engine harness because it had 2 plugs for the power to the distributor. i did not want to run points and could not find the original harness that went with the dash and harness.

i have boxes of harnesses from over the years,but have never sat down and figured out what they are. the only clue i have is 73s were 2 piece harnesses under the dash. the rest is a blur to me

I have a 73 Harness from a Monte . It was out of a car that had a TH400 & power windows & locks. There is a separate square "piece" that a bunch of wire go into similar to the fuse box (but no fuses) that mounts to the firewall behind the radio somewhere. I remember one of the wires clips onto the deluxe style gas pedal. It's much different than the one on my Malibu in terms of the amount of wires. I may end up using it to convert to the round gauges which I also snagged at the time...but they are the idiot lights so I plan to go with some after market gauges in their place & get ride of the clock for a 2" tach in that spot. I'm still debating all of this & it's not gonna happen till some funds open up. I think I'd go nuts if I had to splice all those wires.

Man that's a lot of wires! LOL. I don't remember the piece that's crossing under the column in your pic being there...what's that connection for?

Mcarlo77 wrote:Wow...that's a whole lotta splicing. I think I'd be inclined to just find a complete wiring harness designed for tach gauge cluster and save myself alot of headaches.

You could just swap the wires around in the harness at the pc board.

That's what I'm going to do whenever I get around to installing my gauge setup. i need to fix the bezel I have since a corner is broken off. I got a piece from another broken bezel to piece into it. then find woodgrain to put on it.

77mali wrote:Man that's a lot of wires! LOL. I don't remember the piece that's crossing under the column in your pic being there...what's that connection for?

thats the wires for my A/M gauges. (negative and light wires)

texan01 wrote:

Mcarlo77 wrote:Wow...that's a whole lotta splicing. I think I'd be inclined to just find a complete wiring harness designed for tach gauge cluster and save myself alot of headaches.

You could just swap the wires around in the harness at the pc board.

That's what I'm going to do whenever I get around to installing my gauge setup. i need to fix the bezel I have since a corner is broken off. I got a piece from another broken bezel to piece into it. then find woodgrain to put on it.

i have some nice bezels with woodgrain. most of mine are black because they came off of 73's. in 74 the bezels became color coded to the dash.

Was gonna say...bezels aren't that hard to find in nice condition and they aren't that expensive.

Okay...so, had some time today and, just to satisfy my curiosity, I decided to run down to the local U Pull and pick the underdash harness off the '75 Laguna sitting down there. This car had the gauges, but not the tach. Instead, it had the Fuel Economy gauge. Would this be the same harness as used with the tach...except for the tach wire that runs out to the distributor?

I have heard that the tach & fuel econ gauge are easily interchangeable and have the exact same "pod" for the gauges to sit in.

That much is correct. Just wondered if there were any differences in, say, the back illumination bulbs, etc. Don't really think so...