12V Conversion

[Brett]

OK here we go

I've sorta decided which direction to go with my truck. Its not going to be very original at all. I want it to look cool, but be better suited to life in the civillian world, kinda like a resto-mod. I'm going to use civillian lights, and turn signals (maybe the teenage drivers around here will be more likely to see them). I will not have any BO lights, but will try to use a Mil. light switch. The hole is already there, and it looks cool. I also would like to keep the waterproof distributor, again its there and looks cool.

So here's where it gets interesting. What would it take to convert to 12v. I have little to no wiring in the truck, so everything would be from scratch. What I would like to do is discuss each individual component in terms of what it would take to run it on 12v. I'll start of with a few, But I would like to eventually go over every component. Oh yeah, and would like to keep the budget in mind. I'm asking alot here I know.

1. Starter
I know it will turn over on 12v but how detrimental is it. It also will turn over slower on 1 12v batt than on 2 batts for 24v, but what if it were 2 batts in parralell for 12v? What are the differences between 12v and 24v units? Could a starter shop rewind it for 12v if necessary?

2. Generator
Could it be used to charge a 12v system? maybe with a 12v regulator? How about fitment of a 12v alternator. Think of the budget here, maybe a junk yard unit from a chevy? (cheap and common).

3. Distributor
The coil has a resistor on it to drop the voltage right. This is to prolong the life of the points. What if you bypass this resistor, and feed the coil 12v will it work reliably? How sensitive are coils to voltage? Most 12v systems use a resistor to cut the voltage for point life as well, but use a bypass circuit from the starter solenoid to give full voltage to coil during cranking.

4. Gauges
An automotive electric book I've had for several years says that there are two kinds of electrical gauges Balancing coil and air-core. The air-core type is grounded only through the sending unit, and requires a precise voltage to be accurate. the balancing coil has two magnetic coils inside that act on the needle one coil is grounded to the panel, and the other is grounded though the sending unit. the difference between the two determines needle position. this type is suposedly accurate over a wide voltage range. I think the original gauges are balancing coil, so will they work on 12v?

That ought to be enough to get people talking what do you think?

Brett

[gwalker]

to operate well you will have to have it rewound to 12v. you could use 2 batteriess but it wont improve starter performance.

you will have to install another alt. the one on the truck is a generator anyway and wont be worth trying to convert to 12v, the GM internal reg. alt. is very popular for its ease of wiring.

the orignal military coil is avialable in a 12v version I cant remember who has them but they do exsist so that will be easy.

on the operating design of the gauges it wont matter, just visit stewart warner, auto-meter, or other gauge manafacturers sites an pick the ones you like, they wont give you a opt to be balancing coil or other anyway they will be what they are. (they arent better than one another just a difference in design is all)both designs will be plenty accurate. The replacement sending unit will likley be a universal fit requiring set-up to your paticular tank depth that is the hardest part to get right.

[pfrederi]

You better get a 12v starter or have yours rewound. You can feed starters higher voltage than their design and as long as you do not over-crank them they will work fine and last a long time. (Old tractors guys routinely convert from 6v to 12 v and use the original starter motor for years). However, you cannot go the other way. Feeding 12v to a 24 v starter motor will burn it out very quickly (amps used increase as voltage drops)

[ELBUFO]

My first experience with 24V was back in the 70's with my Willys M38. I choked on the price of a new starter. Everything else was junkyard cheap (If my memory serves me right there was a flywheel tooth count problem with the civilian starter.). I swapped out everything to civilian 12V except the starter. I cobbled up a set of solenoids to apply24 volts to the starter when needed. I used 2 normally closed, and one normally open to do the job. The Nc's connected + to + and - to -. The NO went from +on bat 1 to - on bat 2. The main power out to accessories was connected to + on bat 1 Gnd was on bat 1. The hot lead to the starter was connected to + on bat 2. I used a horn switch to energize the solenoids, stomped the starter and fired her up. It worked fine for many years. Then came the V6.... There is enough room in an M37 by the battery box to mount this Frankenstein's monster.... I did read a short blurb about a direct replacement non foot stomp starter for the "M", but don't remember where. I am new to the "M" game and have been absorbing way too much too quick.. I think it was from one of the parts distributors??? This would be way better. Oh well brain hurts!!!...John
P.S. Check my figures just to be sure I got it right I'm old.