Proper battery cable installation

[firetruckmatt]

I repair fire trucks and one of the departments I provide service for recently purchased an M35 A2. There has been a Kussmaul brand (common in the fire industry) 24 volt battery charger installed and it does not seem to be operating properly. It looks to me like the batteries are not properly installed/wired. I tried looking through the TM's but couldn't find anything. Anyone have a diagram, or some info that might help me out? Thanks a lot for any help and/or advice you may be able to provide! Really cool site by the way.

 

[gimpyrobb]

The wire from the frame goes to the first battery ground. The (+) positive terminal from that battery connects to the second battery's ground. The positive from that battery connects to whats left. I will PM my cell number if you have more questions.

 

[firetruckmatt]

Yea, that's how I thought a normal 24 volt system would be wired, I didn't know if these trucks were wired different for some reason. This particular truck has the two ground terminals jumped together and wires coming off of each of the four terminals going to who knows where??? I think I am going to have to just tear it apart and start from scratch. Thanks a lot for the help!!!

 

[SteveKuhn]

Your description sounds sorta like my friend's M37-turned-fire truck where they tapped off the 2 batteries individually for independent 12v stuff. You might consider that.

Steve

 

[Warthog]

From the TM 9-2320-361-20 Unit Maintenance Manual, page 2-77



On many trucks (not all) there is an additional heavy cable on the first negative and last positive terminals. Those extra cables go to the slave port on the side of the cable. The slave port allows for jump starting other similar trucks or equipment

 

[doghead]

The full vehicle schematic is found in TM9-2320-361-24-2.

 

[firetruckmatt]

The wire from the frame goes to the first battery ground. The (+) positive terminal from that battery connects to the second battery's ground. The positive from that battery connects to whats left. I will PM my cell number if you have more questions.

Do these trucks call for wet cell batteries or dry cell batteries???

 

[Warthog]

Usually wet cell, but the latest is AGM (absorbed gas mat). You can use just about anything as long as the CCA is high enough.

The stock battery is a 6TL (or some version). Many of us have used the Group 31's as replacements. Easier to find and they fit the box.

 

[whiskey357]

sounds like each Co. that provides charges is somewhat different for each installation....go with the TM...I have and it works.....(wife hands me my glasses at the right time ...Best of all on this good luck)

 

[m-35tom]

Yea, that's how I thought a normal 24 volt system would be wired, I didn't know if these trucks were wired different for some reason. This particular truck has the two ground terminals jumped together and wires coming off of each of the four terminals going to who knows where??? I think I am going to have to just tear it apart and start from scratch. Thanks a lot for the help!!!

does it start and run? if the negatives are tied togeather it has been changed to 12 volt.

 

[Jeepsinker]

Ok, how many batteries does it have first? Two, or four?

 

[goldneagle]

How about some pictures....

 

[Floridianson]

Like said it might have been switched to 12 volt.

 

[Heavysteven]

Maybe this will answer your question.

http://www.youtube.com/watch?v=ObcxTFX4EKE