How to power dash circuits with engine removed

Deadguy · Post by **Deadguy** » Fri Dec 16, 2011 7:07 pm

I am almost done installing the 1963 directional upgrade on my M38A1. I want to make sure everything is laid out correctly. I know as well that some of the existing lines were used in new spots. The easiest way to check all of this would be to simply turn on my truck. The problem is, the engine has been pulled, and is away at the rebuilder's right now. Is there a line into the light switch that I can provide battery power to, so I can check all the lights?

oilleaker1 · Post by **oilleaker1** » Sat Dec 17, 2011 7:50 am

The wiring harness gets it's power at the hot starter post. You could use your battery/ batteries as normal and connect to that lead that tightens on the starter post and the other battery ground should still be hooked up. Just make sure any other leads to appliances that were disconnected don't short to the frame or ground. John

Deadguy · Post by **Deadguy** » Sat Dec 17, 2011 11:54 am

Alright, I know the wire you are talking about. The engine, along with the starter and generator, have been pulled from my engine bay. It is entirely empty right now. Is there only one wire I need to hook up to a current?
Oh, and I assume I need to pull power from the second battery in the row? I have an auxiliary wire running off the first battery, but I assume I need all 24 volts to fire up the system?

oilleaker1 · Post by **oilleaker1** » Sat Dec 17, 2011 3:58 pm

The corresponding wiring diagram for your application whether it's 12 or 24 volt should show the correct leads. If you are still 24 volt for the bulbs, yes use both batteries as normal.

Post by **wesk** » Sat Dec 17, 2011 11:15 pm

#4 and # 82 go together and keep them insulated so they can't accidentally short out. 4 goes from the voltage regulator to the starter terminal and 82 is the Positive battery cable between the starter and the battery set. Make sure that there are no wire terminal ends touching bare metal anyplace. Especially under the dash.

Deadguy · Post by **Deadguy** » Sat Dec 17, 2011 11:49 pm

Unfortunately, there are no numbers on the wires from the harness this guy put in the Jeep. He had a four wire set, with a new line spliced into an existing line for the voltmeter gauge. The spider harness was shot, so I got a new correct 5 wire one from John at Midwest Military, and I've been trying to figure out the wiring ever since. The generator was for a radio Jeep, and apparently has an internal voltage regulator. I hooked up the starter line to one battery, and the light switch had power on my circuit tester, but the lights didn't fire up. Then again, that was 12 volts, so I'll try again with 24. I'll fabricate a line to run off the second battery to the starter wire, and see what i can figure out from there.

Post by **wesk** » Sun Dec 18, 2011 1:00 am

The only way anyone can respond with an intelligent suggestion or advice is for you to draw out the wiring you now have and post your actual "as wired" diagram here for review. If this is more than you wish to do then at least trace each wire and mark each end then when you need help on where to connect any wire you then tell us which wire it is by describing where it starts and where it ends. Any other shotgunning methods trying to resolve over the web how a wire should go will at some point end up with a smoking jeep, a mad owner, and a lot of advisors feeling bad.