Chim_Chim

Need Help with my Gauges. I just finished installing a Lectric Limited Dash Harness in my 64 because the main bundle of wires were showing bare wire and there seemed to be a lot of melted wires. Prior to replacing the harness, both the Fuel gauge and Temperature gauge worked just fine with the ignition turned off and while I was driving. Once I replace the Dash Harness and reinstalled the gauge cluster, I started the car and the fuel gauge, which should have been at 1/2, was pegged just past the F mark. The Temp gauge points to about 5 O'clock and it moves a little when I cycle the key, but only a 1/16" to 1/8" at most. I called Lectric Limited's customer support and they said that there is no way the wiring would make the gauges do this. I know the gauges work on resistance, but confused as how they could be reading differently after replacing the harness if it is not due to the harness.

Any help would be greatly appreciated.
Chim Chim

BWT

Sounds like the ground wire that goes to a single terminal at the top of the cluster (just left of center) is disconnected.

vjjack04

Chim Chim,
Did you re-look the connectors on each? In other words, did they come terminated with connectors on them from LL or did you put them on? I would start by making sure I re-checked those and replace with new crimped on Packard style connectors. Now if you've done that, it could still be a grounding situation. You'll have to ensure where the grounds are has been scuffed to bare metal. Also seems to me LL would have been more helpful (frustrating I am sure). Also check continuity across the new wires.

Chim_Chim

Thank you for the suggestion BWT. I pulled the instrument cluster back out and realized I had switched the brown and black wires. I had the brown wire at the grounding stud and the black wire at the radio resistor. Switched the two and everything works great.

Chim_Chim

vjjack04,
Lectric Limited wiring harness came fully terminated as OEM with all wires being the same colors and connectors being the same as original. As I stated before, I had used the brown wire as the ground wire vs using the correct black wire. I appreciate your response.

silver837

Always good to hear when the OP fixes there problem .

rich5962

Brown is the ACC(Acccesory) feed. It is UNFUSED there. That normally gets only connected to a Radio suppression capacitor if RPO U69(radio option) exists.

Your gauges acted unusually because their ground potential was floating.

Luckily, the Cluster is somewhat isolated from chassis ground otherwise key in RUN or ACC could've caused some melting. That Brown circuit also feeds the fuse panel for Radio, Heater fuses, and also feeds Wiper/Washer functions, (also rear Blower if a 64/65 coupe, iirc).

But.... the cluster may get "some" grounding from Tach & speedo cables, so there may have been some Brown wire heat going on, as its sourced from the IGN Switch. Direct BAT+ feeds it through the switch.

Check your IGN Switch Brown wire terminals in harness and switch. They may have been compromised with arcing, and if so, you'll want to clean them up.

Rich

vjjack04

Chm Chim,
Glad you fixed it.
Have a good day.