battery problem

[beastm35]

Hello, I may have a battery issue not sure, does anyone have trouble starting there deuce after 4 or 5 days? I have a solar charger that works great but 3 to 4 days with no sun is a problem, I've checked for dead short found none, the front battery closest to the front of truck is dead the truck should pull from both I'm thinking not just one battery.Is there a cable diagram of how the battery cables are hooked up? something is not right I do have a winch hooked up the the front batt, but its not on or drawing anything when not in use. this is the third battery i have tryed and still gos dead after a time any help please. Thanks P.s the truck is a m35a2..

 

[cattlerepairman]

https://www.steelsoldiers.com/showthread.php?81184-Dead-Battery-Situation-M35a2
https://www.steelsoldiers.com/showthread.php?142159-m35a2-batteries
https://www.steelsoldiers.com/showthread.php?81543-M35A2-Charging-system-questions
https://www.steelsoldiers.com/showthread.php?15908-Draining-one-battery-more-than-another

Here is a diagram (for the FMTV with 2 batteries...Deuce is the same): //uploads.tapatalk-cdn.com/20171122/ffc59c317520c574452d64f62f5c31d5.jpg

Drawing a high load from only one battery to support 12V is not recommended. If you winch a lot you may want to have a third battery dedicated to a 12V winch circuit, preferably with a 12V dual alternator setup.

 

[glcaines]

Hello, I may have a battery issue not sure, does anyone have trouble starting there deuce after 4 or 5 days? I have a solar charger that works great but 3 to 4 days with no sun is a problem, I've checked for dead short found none, the front battery closest to the front of truck is dead the truck should pull from both I'm thinking not just one battery.Is there a cable diagram of how the battery cables are hooked up? something is not right I do have a winch hooked up the the front batt, but its not on or drawing anything when not in use. this is the third battery i have tryed and still gos dead after a time any help please. Thanks P.s the truck is a m35a2..

I'm running Interstate 6TLs. My deuce has sat unused as much as 3 months without a solargizer or battery minder and it fires right up, even in very cold weather. If you don't have anything hooked up that could drain the batteries, I would suspect inferior batteries. However, even with inferior batteries, they shouldn't discharge the batteries in 3 - 4 days. The batteries are hooked up strictly in series. Are you absolutely certain that you don't have something draining the batteries? You might want to fully charge the batteries with the battery cables disconnected, including the solargizer disconnected, and see what happens to the batteries. It is also possible that the solargizer is malfunctioning and draining the batteries.

 

[TGP (IL)]

First thing to do is charge both batteries.
Then load test them separately.

Your going to find a bad or weak battery.
Tom

 

[jetman10]

I have a question . How come no one cautions when working around 24 volt system , that they are pos ground ?

 

[NDT]

Why do you have the 12 volt winch connected to the battery to the front of the truck? It should be connected to the battery to the rear of the truck. The battery that has the negative cable going directly to the frame under the cab.

 

[glcaines]

I have a question . How come no one cautions when working around 24 volt system , that they are pos ground ?

They are not positive ground.

 

[Karl kostman]

Hey Bastm35 I am not sure how long you have had your truck, sounds like not long at all, there is a section on this site where you have full FREE access to the technical manuals for this truck it has all the answers for questions such as yours. I would strongly suggest you take a look at these then decide if you want to buy a set to use when working on your truck. It may sound boring and you may already know everything there is to know about your truck but trust me you will grow to love you TMs!!
Karl

 

[jetman10]

This is to glcarnes, I didn't think so but this TM is confusing . TM 9-2320-361-24-1 000300 says, " the batts are wired in series creating a 24 volt system. The batts are positively grounded directly to the chassis . The neg goes the the starter solenoid terminal .

 

[dmetalmiki]

Why do you have the 12 volt winch connected to the battery to the front of the truck? It should be connected to the battery to the rear of the truck. The battery that has the negative cable going directly to the frame under the cab.

'Because running from the rear (Last) battery would flash 24 volts if something shorted to ground'.

Ground (anywhere) And There will always only be 12 volts using the first battery.

 

[dmetalmiki]

I have a question . How come no one cautions when working around 24 volt system , that they are pos ground ?

They, (any 24 volt truck system) Has negative grounding.

A lot of cars used to be positive earth (ground) and that resulted in excessive corrosion at the chassis.
Manufacturers then reverted back to Negative ground. (which alleviated the problem).
Your truck is (very definitely) Negative earthing. (grounding).

 

[glcaines]

This is to glcarnes, I didn't think so but this TM is confusing . TM 9-2320-361-24-1 000300 says, " the batts are wired in series creating a 24 volt system. The batts are positively grounded directly to the chassis . The neg goes the the starter solenoid terminal .

I see why you are confused. The TM 9-2320-361-24-1 000300 is incorrect. The truck is negative ground, period. I have attached a copy of the schematic for an M35A2.

 

[rustystud]

I see why you are confused. The TM 9-2320-361-24-1 000300 is incorrect. The truck is negative ground, period. I have attached a copy of the schematic for an M35A2.

There are quite a few "errors" in our TM's. If in doubt about something ask.

 

[beastm35]

I have a question . How come no one cautions when working around 24 volt system , that they are pos ground ?

Hi, no they are (neg) ground the power wire go's to starter..

 

[beastm35]

https://www.steelsoldiers.com/showthread.php?81184-Dead-Battery-Situation-M35a2
https://www.steelsoldiers.com/showthread.php?142159-m35a2-batteries
https://www.steelsoldiers.com/showthread.php?81543-M35A2-Charging-system-questions
https://www.steelsoldiers.com/showthread.php?15908-Draining-one-battery-more-than-another

Here is a diagram (for the FMTV with 2 batteries...Deuce is the same): //uploads.tapatalk-cdn.com/20171122/ffc59c317520c574452d64f62f5c31d5.jpg

Drawing a high load from only one battery to support 12V is not recommended. If you winch a lot you may want to have a third battery dedicated to a 12V winch circuit, preferably with a 12V dual alternator setup.

Hey thanks no I dont winch alot but is was the solar charger pulling back power from battery. we think.

 

[beastm35]

Hey Bastm35 I am not sure how long you have had your truck, sounds like not long at all, there is a section on this site where you have full FREE access to the technical manuals for this truck it has all the answers for questions such as yours. I would strongly suggest you take a look at these then decide if you want to buy a set to use when working on your truck. It may sound boring and you may already know everything there is to know about your truck but trust me you will grow to love you TMs!!
Karl

Hey Karl thanks I had the truck for 3 years and still learning I have a lot of know how on trucks but sometimes the dumbest things happen. It was the solar charger pulling back power from the battery..Thanks again..

 

[cattlerepairman]

I am glad you identified the source and I hope it did not damage the battery.