THIS IS A REPLY I GOT FROM ANOTHER SITE
[h=3]
Re: swapping 24 to 12[/h]
by
just me » Sat Dec 19, 2015 8:28 pm
I have no build thread, but the info was put on the facebook page along with some pics.
Basically, when I got my truck, there was not an inch of good wiring left. The original harness had rotted and the PO wasn't exactly good with wiring.
So, I bought an entire new harness for a B1 with Douglas connectors (so I could have turn signals) from Joe at Vintage Wiring of Maine. Told him I didn't need the 24V charging wiring or the distributer plug. He provided a pigtail for the distributor and I made the charging harness from the correct wire and Douglas connectors.
Installed the harness and 12V lamps in the lamp housings, headlamps, High beam indicator and instrument lights.
Intercepted the lead to the Breaker that feeds the spider harness and ran it through a 10amp 12V to 24V DC convertor and fed that to the breaker/spider.
Now, the instruments and all of the associated senders are still 24V and do not have to be changed. You keep the red backlighting. (With the loss of the dim setting as the resistor in the 3 lever switch drops the voltage too far to see the filaments. (If you have a switch you can open, you could change that resistor.))
The generator gauge now shows the condition of the convertor and I added a 12V gauge and ammeter to show condition of charging system under the dash. One other thing however, the stock generator gauge will read in the yellow band as the convertor puts out 24V and that is the yellow band showing not charging, Green starts at 26V.
I recalibrated the gauge so it points into the green at 24V.
Since the 12V starter didn't have the foot switch, I mounted a CJ2 start pedal on a fabricated bracket in the original location and made cables from Batt to switch to starter. I did not want a start solenoid, keyswitch or any of that stuff.
It has been working for a year now with no issues and I use the truck as a daily driver.