While I had the dash apart to put in my clutch pedal box I decided it was a good time to install the 140 GT cluster I picked up. There are 4 connectors that go to the dash cluster. Three of the connectors are 4 pin and one is a 2 pin. I ran a new wire from the neg side of coil to the tach connector. Also pin 7 is missing in my connector and I found out that powers the OD light in the GT cluster. I had a pin with wire lead on it. I inserted it into pin 7 and coiled the wire for later when I get the M410 installed and I wire up the OD.

I put the cluster on top the steering column and connected it to test before actually mounting the cluster. I have some troubleshooting to do.

The tach, temp gauge, and high beam light worked and the gauges all lit up. No other idiot lights worked. The gauge dimmer wasn't worked as well. Also, the fuel gauge wasn't working.

I had changed all the bulbs. I looked at the twist lock bulbs for the idiot lights. If you didn't twist them just right they would not line up with the circuit board correctly. I did that and tested again. All idiot lights were now working except oil light. I swapped org cluster in and the oil light didn't work. I don't recall if it did before. I would think I would have noticed that. Will look at that closer. The contacts on the twist lock that the bulb fits into are tarnished. Look like a standard item. Going to see if I can pick some up and replace all 6 twist locks that the bulbs fit into.

I was reading a post about the voltage stabilizer. There was talk about the nuts on the gauge that make contact with the cicuit board. Going to check mine out to make sure they are tight and hopefully this fixes the fuel gauge. I did swap the stabilizer from the org cluster. Both the fuel and temp gauge worked with that cluster.

On the cluster dimmer. I looked at teh dimmer switch. It has three spaded leads. One lead appears to go to ground on the cluster face. The other two leads are there but have been cut off close to the spade connector. I can tell the wire leads were red. Almost looks like the dimmer was by passed. With just one wire going to ground it can't be functional. I can't tell were the cut leads would have gone. Power to the bulbs seems to come from the circuit board and goes serial to each bulb. One would think it should go from the circuit board to the dimmer switch and then out to all the bulbs. Some member had posted a link to a page showing the GT and Rallye clusters but doesn't show the dimmer switch to tell.

http://www.fieldlines.com/matt/gauges.html

Was hoping someone might have such a cluster and maybe not installed and can trace the dimmer circuit for me.

Craig