Regulator gone bad?

[70Duster440]

Started tearing my custom dash and column apart to fully expose the harness and also replace the ignition switch.

This is a little off topic but I thought I'd show the steering shaft/bearing removal tool I threw together. It mimics the factory tool.

In order to get to the ignition switch you have to remove the upper section of the column. Some people get super lucky wiggling it off. Others are more barbaric and use screwdrivers to pry it off. I have a new upper bearing in there so there was no wiggling and prying it off was totally out of the question.

I took an extra turn signal switch retainer and welded a tube, washer, and nut to it. Section came off easy as pie. Once it's off you remove the sleeve from the lock plate hub, the snap ring, drive the roll pin out, and slide the lock plate off. The switch is easily accessible now.

 

[70Duster440]

Found some interesting things today (in case anybody cares).

With my dash out and AutoMeter gauges on the bench I took a regulated test bench power supply and connected it directly to the Voltmeter. Found it was almost a full volt off in accuracy. (I used a digital multimeter to verify the voltage of the power supply at the load).

Ran a test on the electronic speedo and discovered it wouldn't operate at all at 12v., the LCD odometer would just start to come on at 13v, and would operate properly at no less than 14v. According to AutoMeter they're supposed to work with as little as 10v. So they're off for repair. With as expensive as they are and with as few hours on them that I have, you'd think they'd work better. The whacky speedo is what started this whole thing!

Then I started to unwrap the dash harness looking for the factory splices. I found two different wires with melted insulation in one spot. Neither of them appeared to have shorted. But it soon became obvious that someone had been inside for a repair in the past and done a good job of rewrapping the harness. You couldn't tell it had been unwrapped. Apparently, the main black power feed had overheated and been replaced between the bulkhead and the main splice with a simple crimp connection. On one of the damaged wires (for backup lights) they simply wrapped electrical tape around the melted insulation. The other wire (high beam indicator) melted right next to and bonded with the main red power feed. No attempt was made to fix it - or it melted at a later time. Both were near each other and one of the splices but why they melted where they did is a mystery to me.

I removed the tape from all 3 factory splices and they appear to be okay but I think I'll redo them anyway.

 

[67Dart273]

.............. regulated test bench power supply and connected it directly to the Voltmeter. Found it was almost a full volt off in accuracy...............................................

electronic speedo and discovered it wouldn't operate at all at 12v., the LCD odometer would just start to come on at 13v, and would operate properly at no less than 14v. .................................................

........................unwrap the dash harness .............................found two different wires with melted insulation ...........................main black power feed had overheated and been replaced.................with a simple crimp connection.......................... other wire (high beam indicator) melted right next to and bonded with the main red power feed. .

!!! WOW !!!

Sometimes it pays to "dig in" doesn't it? When I modified my ammeter to a cheap Sunpro voltmeter, it was way more accurate than yours, and has a little trim pot inside to adjust.

 

[70Duster440]

I sent my speedo and voltmeter in for repairs. I like being able to communicate directly with a tech (Cory) there instead of some customer service rep. I think he was a little surprised at the behavior of the speedo but didn't mess around. Both guages were out of warranty but he sent me brand new ones for the cost of bench time ($45). He also personally bench tested the new ones before sending them. Got a lesson on hysteresis from him with regards to voltmeters too.

I got them back in Dec. and tested them myself. The speedo now turns on and operates as low as 8 volts (instead of 14) and the voltmeter is more accurate.

While I was waiting for them I repaired the damaged wiring (above), replaced the main factory splice, ignition switch, new bulkhead fusible link, cleaned bulkhead terminals (again), and soldered critical factory terminal crimps. Main interior power still runs through a bulkhead terminal.

Finally, I nearly installed a late Mopar denso style alternator but instead upped my idle RPM's by 100 or so. It's well above 12v on the guage now at idle and drops to around 12 with the headlights on. I can live with that. And if I decide later that I can't then I'll throw that other alternator on - it's just not as pretty.

 

[BillGrissom]

Re that wire damage, I would repair them in place. Use paint on "Liquid Tape" and after that hardens, wrap each with self-fusing silicone tape. Then rewrap the harness. To avoid future melt-downs, nice to put the bigger loads on relays in the engine bay. That will spare your ignition and headlight switches too.

I recently re-did my under-dash harness in my 65 Dart. It appears the in-harness junctions for the Batt (red) and Accessory (blk) were made by welding (or brazing) the copper wires together, with some sort of square die. My junctions looked only half fused together and had slight green corrosion, so that might be where your heat was generated.

 

[67Dart273]

It appears the in-harness junctions....................... looked only half fused together and had slight green corrosion, so that might be where your heat was generated.

In my lifetime, I've found a number of these that outright failed, and recently was thanked in a PM by a member who found his splice had failed.

These are certainly worth checking, especially now that these girls are getting so old.

 

[70Duster440]

Those melted wires were near the big main splice but I question whether they were due to it. Like I said, someone had been in there before doing repairs. I replaced the sections of damaged smaller gauge wire with new wire soldered and shrink-wrapped.

I cut apart and replaced the big main splice with heavy crimped and soldered connections. A new heavy gauge power feed comes in from the bulkhead up to that splice where it branches off to the fuse box, ignition switch, etc. Extraneous wire and old repairs are gone. Think I'm in good shape now.

 

[Rice Nuker]

Sweet detective work!

Thanks for the updates!

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