Under the passenger seat isn't there a battery wiring schematic Data-Plate?
Isn't there a small wire that is a dedicated 12V wire you need to hook up and
isn't there a ground AND positive small gauge wires that needs
to be connected as well? Not just the big
main wires but 2 smaller wires too?
I suggest your friend did not reconnect the new battery's correctly.
I have been there and seen this and it was a bitch to get
right / being ignorant like I "was?" (debatable I know! HA! )
He needs to read the TM's / SCHEMATICS and find out just what is supposed
to go where, and make it so, not almost right, but exactly like it
is supposed to be wired or EXPECT big issues.
Look for the wiring schematics in the TM's!
It will all of a sudden come to him after you study it, I DO Believe.
For some reason I remember a 59? wire or something in there, a ground and a 12V lead plus the big wires ?
It is confusing, you need to study the wire schematic and take
deep breathes and put it back to OE condition w/o guessing or EXPECT issues!
This is NOT your problem, IMO. I am pretty sure your buddy eff'd up
when he put in the new battery, in-so-much-that he did NOT keep track of
what went where and or a small wire broke or shorted out. The 2 smaller
wires I speak of "can" ground against the cab floor, pull all batteries ot inspect I
and YES, I know it is a LOT of work, (Be sue to rotate batteries and charge
each battery independently when pulled. I bet if he pulls
all batteries he will find the wires he forgot laying between the two rows of batteries.
BUT SOME HOWEVER,
The M939 Series of trucks also have a MAJOR FLAW / HISTORY, that being the main battery wires.
Usually it is the + or - main power wire from batteries to starter, that loose there insulation near
the DS rear of the engine block. It is pretty much impossible to see this
anomaly w/o doing real work. If you can not see 100% of every inch of
those wires, I mean all sides all the way aroud, you are "Assuming" they are ok.
You HAVE to make SURE!!!!!!!!!!!!!!!! It is a BITCH too! Patience....
I could only find this issue by first, being TOLD about it, then,
by disconnecting the wires at the batteries first,
then disconnecting the same wires at the starter and pulling and
moving them back an forth so as to try to see ALL around every wire
110%! So you can see all parts of the wires that
YOU CAN NOT SEE under from under the truck! If you are persistant
and do a GOOD JOB looking you might all of a sudden see where
one of those massive cables has had its insulation
rubbed clean off raw and it is grounding to the block!
BELIEVE IT.
This issue should be a 5TON Sticky.
I fixed mine temporarily buy sliding a heavy piece of dishwasher rubber
drain hose over the battery cables from the starter w/o cutting the hose
longways, but by just sliding it down over
the battery cables covering the bad spots.
BE FOREWARNED!!!
ALSO, ALL 5 TON OWNERS:
You Need to PULL all GROUNDS and clean ALL surfaces to bare metal, I MEAN
ALL SURFACES, and reassemble absolutely CLEAN to BARE Metal with DI-Electric grease and
make SURE you use Internal / Eternal combination STAR washer between the frame and'
the ground wires / straps. I added 2 more ground wires too, from the cab
to the frame, DS rear and from the bed to the frame at the fuel tank ground too.
These trucks take a LOT of work to keep them mission ready.
Yes, I can make mistakes................... see my sig line
