dummy : Running 12V AND 24V????

Running 12V AND 24V????
Post by dummy on Jul 3, 2006, 9:18am

Bought a '68 M-715 w/ no engine/t-case/butchered suspension/no brakes a year ago, stored it at a buddy's house, and just dragged it home about a week ago. Trying to get it up and running for the Ouray FSJ Invasion in about 3 weeks. Hopefully gonna drive it from Los Angeles to Colorado and back. (why isn't there a smilie you can select that's blowing his brains out?)

Drivetrain won't be a problem, but I'm not, shall we say electronically gifted like Over2land. Last night I threw a 12V battery in to see if the PO converted to 12V and it looks like he didn't. Some of the blackout lights and dash lights came on, although pretty dim. The headlights, stop lights, and a few others didn't work.

I'm running a 12V small block Chevy. How can I run the chassis system off 24V while keeping my 12V alternator. Anybody got a link to a cool isolator or some type of RV something or other that'll allow me to run both 12V and 24V with my 12V alternator?

Re: Running 12V AND 24V????
Post by dummy on Jul 3, 2006, 9:30am

Found a couple like this http://www.surepower.com/pdf/ebr_mar.pdf#search='24V%20and%2012V%20isolator'

Wondering what any of you used. Don't have time to do things twice if I get it wrong.

Re: Running 12V AND 24V????
Post by boghog on Jul 3, 2006, 9:41am

I would just switch the bulbs to 12 volt ones and go all 12 volt. Find the guages from an old jeep in the salvage yard, or buy a new guage set from Summit. The only guage that will give you any kind of problem would be the fuel guage, but Im sure one of the guys on the site here can pipe-up on a good set up for the fuel system. I would bet there has to be a few different ways to set it up. There used to be a link or tech article on the subject. Good luck.

Re: Running 12V AND 24V????
Post by fisherman on Jul 3, 2006, 9:47am

I have the part # out in the shop for the Napa 12 volt fuel tank sending unit. That is in the works right now. I can get it later today. Fisherman

Re: Running 12V AND 24V????
Post by brute4c on Jul 3, 2006, 10:02am

The best way to do the dual voltage system in the long run, from a standpoint of parts life and reliability, is to run 2 alternators, one for each voltage, and 3 batteries, a single 12 volt in the 12 volt alternators system and dual 12 volters for the 24 volt circuit. Running either system without a battery is not recommended.

Re: Running 12V AND 24V????
Post by brute4c on Jul 3, 2006, 10:04am

Well, to add to that....if you can get a steup up or step down converter, depends which way you want to go...sounds like a 12 to 24 volt step up would be your need...that will handle the amps you want, then you can do that. Remember to upgrade the 12 volt alternator to handle all the extra output and maybe consider a dual battery, in parallel NOT series like a 24 volt system has, to halp further.

Re: Running 12V AND 24V????
Post by dummy on Jul 3, 2006, 12:44pm


Quote: <TABLE class=bordercolor cellSpacing=1 width="90%"><TBODY><TR><TD width="100%"><TABLE class=quote cellSpacing=0 cellPadding=2 width="100%"><TBODY><TR><TD width="100%">I have the part # out in the shop for the Napa 12 volt fuel tank sending unit. That is in the works right now. I can get it later today. Fisherman</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>

Allright. Turns out the bulbs were converted. The guy's wiring just didn't make any sense whatsoever. Got it figured out now. One headlight is high beam when the other is low beam so I've gotta pull that back apart and swap a wire.

I'd appreciate that sending unit number when you get around to it, but there's no pressing rush.

One other thing - will the oil pressure and temp gauges read off the 12V sending units on the 350 or will those gauges need to be swapped out too? I'd like to keep as much stock stuff as possible.

Re: Running 12V AND 24V????
Post by brute4c on Jul 3, 2006, 1:03pm

The Napa part #501-1742 and has the sending unit (tank) plus the gauge (dash) included for around $30.00