gauge setup question for yall?

[Tex_50613]

I have a gauge cluster out of a '74 C-65 that I plan on using in my 85 K-30 that I'm installing a 7.3L diesel in to render stock manual gauges (oil and air pressure specifically), also to give me a tach. and back date the truck to go along with the '73 front clip, the question I have is what additional wiring or re-wire do I have to do to the 85's interior harness to use the 70's stock cluster with tach with the fuel gauge in it (if they work) also a good place to have that gauge repaired if it doesn't, also did Chevy ever run a volt meter instead of a amp meter? 95% of the Chevy's I've had up to this point have all had Idiot lights or aftermarket gauges.
here's the cluster I plan on using, I also have a spare light truck cluster if I have to replace any of the other gauges that may mot work after I get it all hooked up

[J Knight]

I don't know the procedures to repin but I've heard if you plug in a 73-76 cluster with amp gauge in a later model it will result in instant meltdown of your wiring harness.
BTW, how did you get the odometer 0 ed out??
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[Tex_50613]

Originally Posted by J Knight

I don't know the procedures to repin but I've heard if you plug in a 73-76 cluster with amp gauge in a later model it will result in instant meltdown of your wiring harness.
BTW, how did you get the odometer 0 ed out??
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that's my little secret but I'm sure you can find something on here about it, I'll just say this, it's a pain in the rear

[Jonboy]

The gauges in my '74 had a clock and an ammeter. I pulled the pins off of the back of the cluster, and used the hot wire from the clock to power the voltage gauge. There is a ground bar on the left cab pillar behind the gauges; hook the ground to that. On the gauge side, there are three posts. The top one is ground, and I used the one on the right (as installed) side for power. Run the wires through the holes left in the cluster housing, and you have a working voltage gauge.

you may have to repin the plug to match the C-60 gauge cluster. Not a big deal.

[Tex_50613]

well if I have to re-wire anything in the cab I want to know from the get-go so I can do it before I put the truck all back together, I will just say that I have no doubt that I'll be using this cluster in the truck as for the odometer that's my little secret but I'm sure you can find something on here about it, I'll just say this, it's a pain in the rear and if it wasn't for the fact that I'm putting together the drivetrain from scratch and only using the axles from the truck to do so I, what year had the volt meter instead of the amp meter?

[76stepsidechevy]

I think the amp gauge was 73-75. My 76 has a voltage guage.

[motornut]

i'd say add some grounds behind the cluster
I changed from idiots to tach/gauges
watch the plug pin connections...may be worth pokin threw my 78 jimmy thread below

[terryj]

My 83 C-20 runs a voltmeter

[THE "10" SILVERADO]

GM stopped putting the amp in 75. Anything after is a volt meter. Also with a newer model you might have an electronic oil pressure instead of the old non-electronic ones. I have a 77 without electronic oil pressure so I don't know when they switched.

[Jonboy]

78 is the first year for electric oil pressure gauge.

[Tex_50613]

Originally Posted by THE "10" SILVERADO

GM stopped putting the amp in 75. Anything after is a volt meter. Also with a newer model you might have an electronic oil pressure instead of the old non-electronic ones. I have a 77 without electronic oil pressure so I don't know when they switched.

thanks for the info, I know I want to put as many manual gauges in the truck as I can get since I'm swapping in the 7.3l and it looks like the cab will end up having to have a custom re-wire to use the older gauges so I'm gonna use the K.I.S.S. (Keep It Stupid Simple) method so here we go, get the cab done, remove the factory harness, interior painted, and get on a new harness from the fuse panel out

[wilkin250r]

I don't want to hijack the thread, but I also don't want to start a new one because my question is so similar.

What is the "AIR" gauge on the bottom left? I've got a similar gauge cluster, and I'm considering a swap because I like the idea of having a Tach. I have no idea what the "AIR" is or does, and will probably just replace it with the clock I have in my old cluster.

And let me reinforce what what said earlier. Do NOT hook up and Amp Gauge to settings made for a Volt Gauge. The amp gauge is basically a dead short, you'll fry it in a few quick seconds along with all the wiring associated with that gauge, and you'll be lucky if that's all the damage that occurs, it could easily start a fire under your dash.

[Tex_50613]

Originally Posted by wilkin250r

I don't want to hijack the thread, but I also don't want to start a new one because my question is so similar.

What is the "AIR" gauge on the bottom left? I've got a similar gauge cluster, and I'm considering a swap because I like the idea of having a Tach. I have no idea what the "AIR" is or does, and will probably just replace it with the clock I have in my old cluster.

And let me reinforce what what said earlier. Do NOT hook up and Amp Gauge to settings made for a Volt Gauge. The amp gauge is basically a dead short, you'll fry it in a few quick seconds along with all the wiring associated with that gauge, and you'll be lucky if that's all the damage that occurs, it could easily start a fire under your dash.

it's the primary air pressure gauge from the factory on-board air for breaks and stuff on the medium-heavy duty trucks (C-60-70) that were equipped with air brakes, I'm gonna use it for the primary air gauge for the on-board air that I'm gonna install on my truck and am looking for a second one for the gauge to put in my mud truck to monitor the tank pressure for that on-board air system

[hatzie]

Originally Posted by Tex_50613

thanks for the info, I know I want to put as many manual gauges in the truck as I can get since I'm swapping in the 7.3l and it looks like the cab will end up having to have a custom re-wire to use the older gauges so I'm gonna use the K.I.S.S. (Keep It Stupid Simple) method so here we go, get the cab done, remove the factory harness, interior painted, and get on a new harness from the fuse panel out

The Ammeter can be replaced with a 76-79 volt gauge.
The 73-75 tachometers are the least reliable of the factory tachs. It's probably non functional but it can be repaired.

Re-pining the instrument cluster plug to match your new setup is much easier than replacing the cab harness unless you have other wiring woes. The 70's harness will not just plug into the 85. The column will have to be backdated, wiper switch added to the dash, dimmer added to the floor... Those are just off the top of my head.

masterlock posted cluster plug pin-outs in the 73-87 FAQ. These only cover 10-30 light trucks not the 40-80 Medium Duty.

You'll need to trace all the circuits you'll use on the printed circuit of your MD gauge panel and write them down or buy a compete 75 wiring manual that has the 40-80 MD trucks included. Then determine the existing pin-out of your instrument panel plug. From there you can make your own pin-out.

[Tex_50613]

Originally Posted by hatzie

The Ammeter can be replaced with a 76-79 volt gauge.
The 73-75 tachometers are the least reliable of the factory tachs. It's probably non functional but it can be repaired.

Re-pining the instrument cluster plug to match your new setup is much easier than replacing the cab harness unless you have other wiring woes. The 70's harness will not just plug into the 85. The column will have to be backdated, wiper switch added to the dash, dimmer added to the floor... Those are just off the top of my head.

masterlock posted cluster plug pin-outs in the 73-87 FAQ. These only cover 10-30 light trucks not the 40-80 Medium Duty.

You'll need to trace all the circuits you'll use on the printed circuit of your MD gauge panel and write them down or buy a compete 75 wiring manual that has the 40-80 MD trucks included. Then determine the existing pin-out of your instrument panel plug. From there you can make your own pin-out.

thanks for the info, as for the tach the biggest reason I want to use that one is that the fule gauge is in it and if it doesn't work then I'll have to find somewhere or some way to fix it.
I am backdating the entire dash/interior and some of the exterior, I have a tilt column for a floor shift manual out of the 75 c-30 parts truck that I plan on using along with the on dash wiper control the foot operated high beam switch, gauge bezel, and possibly dash pad, I have the entire harness from that 75, and I kept the plug and about 6" of wiring that goes with the cluster from the 75 c65, the only thing stopping me from just swapping in the entire cab harness is that I want to avoid the glass fuses and also have available fuse locations for accessory's (aftermarket stereo equipment, lighting, ect)
here's the build thread for the truck itself
http://67-72chevytrucks.com/vboard/s...d.php?t=489793