ROCK HARVEY
Full Access Member
I’ve been kicking around the idea of a custom gauge cluster for a couple years, and I decided recently to go ahead and attempt it. I learned some things along the way, so I thought I’d make a post to help anyone else wanting to tackle this project.
My reason for doing this is that the flexible circuit board on the back of my instrument cluster separated and failed. I ran a separate wire to get my fuel gauge working, but that and the Speedo were all I had. When my Speedo gauge failed as well, I decided enough was enough. I started by tracing the shape of the opening onto some 1/4” plexiglass, and cutting out circles of various gauge face sizes to see what I could fit:
I ended up with an 85mm GPS speedometer and tachometer, a 2” fuel level gauge, and space for three 1.5” gauges. I went with oil pressure, engine temp, and fuel pressure. Most the gauges are cheap ones from Amazon. I also added separate idiot lights for oil pressure, temp, and fuel pressure. I bought indicators for the parking brake and high beams, but skipped the seat belt warning light. I have a separate EGT gauge that is rectangular and sits in the cubby by the “wait to start” light. The truck is non-turbo, so I didn’t need to fit in a boost gauge. I made the holes in the plexiglass using hole saws in my drill press, very carefully lol. I painted the plexiglass black, and did major surgery on the housing and epoxied the part I needed to the back of the plexiglass. At this point things were looking good:
Notice at this point that I also had to cut away the vertical trim pieces in the bezel/housing. I was able to shave them very close using a sharp chisel, and then sand the remnants down flush. After sanding everything with 400 grit the housing looks like it came from the factory like that. I bought pre-wired sockets for the 8 lights below the cluster, and was lucky that they fit snugly in the holes in the housing. Now for the fun part:
I labeled all the wires in the truck harness, and wired up and labeled the gauge side as well. Some things to note here:
- there is a 500 ohm resistor in the battery warning light circuit. You need to include this in the new wiring as well, because the alternator relies on either the charge light bulb or this resistor to excite the alternator. I drove around for a week with no cluster and my batteries started to die.
- Aftermarket tachs need a signal from the stator on the alternator to run
- To make an idiot light for oil pressure, I bought an “oil sentry” pressure switch for a kohler lawn mower engine. It closes the circuit when the pressure drops below 5 psi.
Next came time to test for the new cluster, and I ran into a major issue. There was not enough space behind the cluster for my new, deeper gauges. I had to cut away most of the plastic behind the cluster in the dash, but even that didn’t give me enough because the air vent is right behind it. I had to cut about 1/2” off of the threaded posts on the back of my tachometer, leaving just enough thread for the mounting nuts and washers. Thankfully after this I got it to mount up. Finally, I decided to make a new plexiglass cover for the cluster since the factory one has a hole in it to press the trip reset on the odometer. I heated up a sheet of 1/16” plexiglass and carefully bent it to get the curve, then cut it to shape on my bandsaw.
My reason for doing this is that the flexible circuit board on the back of my instrument cluster separated and failed. I ran a separate wire to get my fuel gauge working, but that and the Speedo were all I had. When my Speedo gauge failed as well, I decided enough was enough. I started by tracing the shape of the opening onto some 1/4” plexiglass, and cutting out circles of various gauge face sizes to see what I could fit:
You must be registered for see images attach
I ended up with an 85mm GPS speedometer and tachometer, a 2” fuel level gauge, and space for three 1.5” gauges. I went with oil pressure, engine temp, and fuel pressure. Most the gauges are cheap ones from Amazon. I also added separate idiot lights for oil pressure, temp, and fuel pressure. I bought indicators for the parking brake and high beams, but skipped the seat belt warning light. I have a separate EGT gauge that is rectangular and sits in the cubby by the “wait to start” light. The truck is non-turbo, so I didn’t need to fit in a boost gauge. I made the holes in the plexiglass using hole saws in my drill press, very carefully lol. I painted the plexiglass black, and did major surgery on the housing and epoxied the part I needed to the back of the plexiglass. At this point things were looking good:
You must be registered for see images attach
Notice at this point that I also had to cut away the vertical trim pieces in the bezel/housing. I was able to shave them very close using a sharp chisel, and then sand the remnants down flush. After sanding everything with 400 grit the housing looks like it came from the factory like that. I bought pre-wired sockets for the 8 lights below the cluster, and was lucky that they fit snugly in the holes in the housing. Now for the fun part:
You must be registered for see images attach
You must be registered for see images attach
I labeled all the wires in the truck harness, and wired up and labeled the gauge side as well. Some things to note here:
- there is a 500 ohm resistor in the battery warning light circuit. You need to include this in the new wiring as well, because the alternator relies on either the charge light bulb or this resistor to excite the alternator. I drove around for a week with no cluster and my batteries started to die.
- Aftermarket tachs need a signal from the stator on the alternator to run
- To make an idiot light for oil pressure, I bought an “oil sentry” pressure switch for a kohler lawn mower engine. It closes the circuit when the pressure drops below 5 psi.
Next came time to test for the new cluster, and I ran into a major issue. There was not enough space behind the cluster for my new, deeper gauges. I had to cut away most of the plastic behind the cluster in the dash, but even that didn’t give me enough because the air vent is right behind it. I had to cut about 1/2” off of the threaded posts on the back of my tachometer, leaving just enough thread for the mounting nuts and washers. Thankfully after this I got it to mount up. Finally, I decided to make a new plexiglass cover for the cluster since the factory one has a hole in it to press the trip reset on the odometer. I heated up a sheet of 1/16” plexiglass and carefully bent it to get the curve, then cut it to shape on my bandsaw.
