• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

battery cutoff on negative wire

nf6x

Feral Engineer
1,630
50
48
Location
Riverside, CA, USA
I've studied the M939-series wiring diagram and P2P program some more, and it appears that the 12V tap is only used to power the cab heater fan when in low speed mode. I think that a single battery disconnect switch between the negative battery terminals and the chassis should work just fine in this application.
 

Bill W

Well-known member
1,985
45
48
Location
Brooks,Ga
I had one of those on one of my trucks and never got it to work right as far as making good contact, seems I had to really crank down on it.
 

Lou e

Member
30
0
6
Location
USA
I had one of those on one of my trucks and never got it to work right as far as making good contact, seems I had to really crank down on it.
Thank you for your reply. Did you find a better solution? I plan on re-wiring my truck eventually and doing it right with a proper switch but there are other issues I need to address first.
 

tennmogger

Well-known member
Steel Soldiers Supporter
1,579
542
113
Location
Greenback, TN
There's one slight problem with a negative ground disconnect. Of course 12v and 24v pairs of batteries share the ground, but disconnecting the ground still leaves the 12v line and the 24 v lines connected to everything on the truck. That means when you start wrenching on the reverse polarity protector, for one example, you still have the full current of the 12v to 24v 'upper' pair of batteries 'looking at you. That is not safe.

IMHO the only safe way to have a safe battery disconnect on our dual voltage systems is to interrupt both the 12v positive line and the 24v positive line, meaning two switches, or a DPST switch to do both at once.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks