M35a2 Deuce won't Start

[Bsmith720D]

Hello there. I want to first state that I am new here to this forum I tried looking for a thread on this topic but didn't seem to find one. I was having a little trouble navigating around this forum. But what I have found was some pretty good information. The question or confusion I'm having here with the Deuce i recently purchased has to do with the batteries. When we went to go pick this Deuce up, I put two 7 year old red top Optima batteries on the truck that I pulled from my farm tractor. I've always kept them on a tender when not in use. But I can't get them to crank the truck. I have to end up jumping the Deuce with my truck. Once I jump the truck it cranks fine and starts right up. I've went through and cleaned some ground wires with no luck. I guess I just don't understand why the batteries won't crank the engine. I've never had problems with these batteries and operate everything else on the Deuce just fine. I've also charged them individually and put them back in with no luck. I also don't think the alternator is working either. I have to look into that as well. But could some of you shed some well needed light onto me. I thought maybe my starter needs to be gone through but I'm not sure. Because as soon as I hook another 12v to jump the truck it cranks fine. Thanks.

 

[gimpyrobb]

Start with the basics, how are they wired? Neg(-) of the first Batt to ground(frame/chassis), Pos(+) to the Neg(-) of the next Batt. Finally the Pos(+) of the second Batt to the starter?

 

[Katahdin]

Red Optimas will start a deuce fine, but they don't last forever and at seven-years-old yours might be done.

I suggest fully charging the batteries one more time and then give that deuce a good crank. After it fails to start, check the voltage on both the batteries individually with a multi-meter. If one battery shows less than 12 volts after just one crank, then it's time to buy a new battery, or two.

Re the alternator, with the same multimeter, check the voltage coming out of the alternator's + and - wires while the engine is running. You should be getting about 28 volts if its working properly.

 

[gimpyrobb]

In addition to what was said about batteries, they can check good voltage wise but not support a large current discharge. Use a carbon-pile tester to check.

 

[cattlerepairman]

Many places will load test your battery and that usually is a good indicator for whether they have life left in them.
I have come across many batteries (in the fire service) that are maintained on a battery minder and start the truck just fine. One time, in the station. Once challenged a bit outside the station (lights, auxiliary equipment) with the engine off, they collapse quickly, leading to a no-start.

 

[NDT]

Just making sure you understand that the two batteries have to be connected in series.

 

[rustystud]

Just making sure you understand that the two batteries have to be connected in series.

That was my first thought too.

 

[Roaddog58]

Welcome from NE Ohio, new truck, = new batterys=good starts.

 

[glcaines]

Make sure you purchase two identical new batteries if you decide to replace the batteries.

 

[M35a2duece]

I use 2 random deep cycle boat batteries. Works fine

 

[Bsmith720D]

Well. The batteries are hooked up in series. Everything is connected the way that the wiring diagrams show it to be. I went ahead and cleaned every ground that relates to the starter. I also just pulled the starter and opened it up to see if it was carboned up. But it was definitely clean inside. I think my next step would be to try different batteries. And have these tested. But assuming the batteries are whipped after 7 years

 

[DavidWymore]

Load test. What does the voltage meter in the truck (or better yet, a meter on the batts themselves) do when you attempt to crank?

 

[frank8003]

Oh Golly,
You gonnah have truck long time GI.
Just spring for two new batteries, same type , same manufacture date, same same
and clean and re-seat all connections!
I mean all connections.
Probably not starter as you discovered.
View attachment starter troubleshoot.pdf
That one pictured about the alternator Will destroy stuff if it is not grounded properly as per design.
Just put it the way it was when She was new.
Silver plated copper connections with aluminum wires!

 

[DavidWymore]

Betcha not enough CCA, either batts too small or too old. When I got my truck, PO had put two small batts in it. Fully charged, wouldn't start without a jump. I think they need group 31 size, about 1,000 CCA each.

 

[M35a2duece]

Fwiw my batteries are only about 600 amps each and starts awesome every time. Even when cold....

 

[glcaines]

Oh Golly,
You gonnah have truck long time GI.
Just spring for two new batteries, same type , same manufacture date, same same
and clean and re-seat all connections!
I mean all connections.
Probably not starter as you discovered.
View attachment 722893View attachment 722894View attachment 722895View attachment 722896View attachment 722897View attachment 722898View attachment 722899
That one pictured about the alternator Will destroy stuff if it is not grounded properly as per design.
Just put it the way it was when She was new.
Silver plated copper connections with aluminum wires!

I should have mentioned the importance of the same manufacture date as well. Not many people buy two batteries at the same time for a 28 volt electric system. You may have to get the vendor to dig through his stock to obtain batteries of the same age, and this is very important.

 

[Bsmith720D]

Hey. I want to thank you guys for the responses. I will try two brand new batteries in it and see what she does. One thing I need to do is get a new battery box. The bottom of the steel box has rusted to where it's completely gone. I should start with that so I have a place to put the batteries..lol. But for battery wise, I was thinking of getting some cheap Everstart(Walmart) batteries since money is tight at the moment. What are your experiences with these batteries. What size would you recommend.

 

[frank8003]

Is the Plastic Battery Box 12368318 6160013780683 the same for the 5 Ton 2-1/2 Ton trucks?
Perhaps ask in the parts wanted section for metal or plastic battery box? Do they slide the same?
First get a box to put batteries in.
While you await funding and parts do all the work to get all connections clean and tight.
As for batteries just get the highest CCA that you can fit in the box, two matched.

 

[Bsmith720D]

Yes, the plastic Battery Box 12368318 will fit all 2-1/2 ton and the 5 ton trucks. I have found one listed on Eastern Surplus and was thinking on going that route.

 

[glcaines]

Yes, the plastic Battery Box 12368318 will fit all 2-1/2 ton and the 5 ton trucks. I have found one listed on Eastern Surplus and was thinking on going that route.

You definitely want one of the plastic battery boxes.