1969 Dodge Dart Custom Sedan Slant Six, Father-Son Project
This (excellent) forum taught how to pull the instrument panel, so out it came, as we were determined to get the gauges working and the back-lighting functioning! I was disappointed that my USB-powered IVR replacement didnt do the job.
I grabbed an ohmmeter and measured the dark blue wire for the fuel tank sending unit down near the kick panel, and it read 21 ohms (near half-full), so I knew at least the sending unit worked. Likewise, the temperature sending unit measured around 240 ohms (cold un-running engine). Are the gauges themselves bad?? I cant help but worry now that Ill only be able to find gauges for 2-door Darts, not 4-door Darts. (only half-kidding when I say that, but geez! Even the rear package tray shelf is different for sedans, and impossible to find! :banghead:)
But it became quickly obvious what was going on. Those riveted-on pin connectors on the instrument panel circuit boards are feeble, and the one pin feeding the fuel gauge was simply broken off. Plus, two others broke off while being ham-handedly disconnected during removal (by someone who shall remain unnamed). Craaaaap!:oops:
Okay, fine, with an engineer on our team, we figured out a way to fix this. Very small machine screws, lock washers, and nuts to the rescue. Drill out those crappy pins, go to Fryes Electronics, buy more shrink-tubing and generic wire harness connectors, and spend all evening at the dining room table carefully modifying the circuit board connectors.
Note the job of heat-shrink tubing to provide electrical insulation, as well as having to stack washers in order to gain clearances. It's hard to tell from the photo, but there was full-coverage of heat-shrink tubing between screw posts.
Also, we replaced the headlight control switch to rule out a bad rheostat causing failure of the dashboard lights.
Of course, since the ammeter had been bypassed a few weeks prior, and the instrument panel was already out, why not go ahead and cleverly install a voltage gauge in its place? It required some fitting because we ignored the advice on which exact Sunpro model number fits right in. Some swearing may have occurred during its installation. All the gauges' needles were painted the same orange color too, for good measure.
End result: SUCCESS! : Dash lights work, fuel gauge reads, temperature gauge reads (we did this before pulling the motor, and as the motor warmed up the gauge was reading it), new voltmeter showed the battery voltage. :cheers: