M813 Jump Start

[ShermHook]

Looking for a safe procedure to jump start my "new" M813. When I recovered from GL the batteries were dead. GL gave me a jump with the slave cable. never could get the 6TLs to take a charge so I replaced the batteries. Started great with the new batteries. I let the truck sit for about a week and on my next attempt to start I was bummed to find the new batteries drained low enough that all I could get out of them was clickity clickity clack at the starter instead of the sweet purr of the 250. I think I have a ground somewhere that has drained batteries. This is my first MV and my first 24v system so any help is appreciated.

 

[swbradley1]

A new set of batteries that are fully charged will probably set for many months and still start the truck. Mine do. My guess is that you left the battery switch on.

 

[doghead]

It is very possible that when you jumped the truck, your original batteries were bad, alowwing the alternator to go to full output and burn out the rgulator or at least a diode. This could cause a drain(short) when the truck is off.

Charge your batteries. Pull the small wire off your alternator. Let the truck sit for a week or two. If your batteries stay up, your drain is in your alternator. Repair or replace it.

Of course, be sure you have all lights off (top lever straight up), and your glow plug switch off.

 

[Bolkbich]

Another way to see if you have a drain on your batterys is to disconnect the positive cable from the batterys and put a test light between the terminal and the cable.. if it lights the test light you have a draw

 

[doghead]

Yes, and if so, unplug that small alternator wire and test with the light again. That will show you if what I said, was the issue.

 

[doghead]

You can also pull start it. You need to crank in the fuel shutoff override.

Any way you start it, I'd check the output/battery voltage once it's running. Anything over 28 volts, can be a problem.

 

[73m819]

Install a battery cut out switch in the ground, this is a positive on/off switch, off no drain, though if the alt. is bad, as some time your new batteries charge will be to low to start.

 

[ShermHook]

Ok with the Holidays behind me I think its time to get back into this one. Do I need to pull the series cabling from the batteries to charge each of the batteries or not ?

 

[jw4x4]

Yes. Pull the cables and charge each battery seperately, esp. if using a 12v charger.

 

[Scarecrow1]

I had the same thing happen to me and like you I wasn't sure if I made the mistake of leaving something on. I had to remove each battery and charge it one at a time . I also had to take one back to the place I bought it from and have them put a charge on it . Every time I put the little 12 volt charger on it it would just peg the meter and cut the power to the charger off. Like you now I am a little paranoid that I may not have everything turned off so I double check . So far it hasn't been a repeat mistake . I like the idea of the disconnect and bought one but ,haven't installed it yet. They say to put it on the negative side but I don't see why it couldn't be placed on the jumper between the two batteries . I think I will try both and see .......

 

[jw4x4]

The reason for putting it on the negative side is so it will not run the risk of dead-shorting. If the ends of the cable or terminals on the kill-switch somehow touch to ground, its no issue. Which ever way you do it, neg or pos, it still serves the same purpose. Killing the ground is just safer.

 

[Scarecrow1]

Thanks jw4x4 I thought it was something logical. I will put mine on IF it ever stops raining here . I don't know if the chances of a short are really that high being the location but, I see where it is possible ............

 

[ShermHook]

I think I found the problem. The small cable going to the alternator had a large rip in the sheathing in the engine compartment. I repaired the cable, charged the batteries and have not had a repeat problem since. Im pretty sure I had all the electrical accessories shut off and did not drain the batteries down but I am carefully checking the switch position from now on. Now I need to get onto the brake lights and rear turn signals.