QuestionHi Van, The information was very helpfull. I inspected all of the wires and they appear to be in good shape. I found what I think are the fusable links. Are they rubber, about the diameter of a large pencil, and about 1 inch long? How can I tell if they are damaged and if so I do I replace them? I have removed the starter and both alternators to have them checked out.If they are OK what else might you suggest we check out to see what the source of the smoke was?
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Hi Van,
My son has an 1986 military diesel truck with the 6.2 liter diesel that has run fantastic. It had two 12 volt batteries wired in series when he purchased it. Yesterday he thought the batteries were dead and attempted to jump it with a Ford pickup with a 12 volt system. He connected the jumpers to one of his batteries and shortly after that a great deal of thick white smoke came out from under the engine primarily on the starter side. Now nothing happens when you turn the key. I have an idea what happened but hoped with your expertise that you would be able to diagnose the problem and tell us what he most likely might have damaged and what we will need to do to fix it. Sincere thanks in advance for any help you may be. Scott
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Hi Scott,\
I jump them quite often with a 12 volt Ford.
The trick is to jump to just one battery, and to connect the POLARITY correctly.
When going battery to battery, don't go by cable color. Use the + and - markings on the batteries, and as long as you go from the Ford + to a battery +, and from the Ford - to the BATTERIES -, you are fine. DON'T go from the Ford - to the Military truck frame, engine block, or other parts, unless you are jumping to the battery that connects directly to the block, which is normally the front battery in the Mil truck.
That front battery, by the way, is the one that usually needs jumped, because it is the one that provides the 12 volts used by the truck.
Almost EVERY single thing in the truck runs on 12 volts, by the way.
The only thing that uses 24 volts is the starter and volt meter.
Now, the smoke...
I'd follow the battery cable from the battery to the starter solenoid, and see if it had rubbed through, and was shorting to the frame or engine block, which would explain why he was needing to jump it in the first place.
Connecting his 12 volts, even wrong, shouldn't damage the starter or solenoid. it would be more likely to damage the Ford system, if the Mil batteries were charged up.
On the firewall, behind, and below the rear battery, there are a bunch of fusible links. Check them to see if that is where the smoke came from.
If it is, connect the burned link back together, and then connect your Ford as described, and try it again.
If you have a volt meter, check your Mil batteries with it.
Normally the rear one will be charged, and show 12 volts. The front may well show less than 12 volts, cause things like blackout lights, and GPFU filter switches can be left on, and they will drain that front battery.
This information will work on almost any of the Chevy pickup military vehicles, but when you get into the charging systems, the truck that was used as an ambulance has a completely different system.
The starting system is the same, though.
Van
AnswerHi Scott,
Yes, that is what the fusible links look like.
Actually, the pregnant looking thing is the splice that connects the fusible link to the wire. The link itself is the small pigtail of wire between that splice and the stud right there about four inches away.
The cover of the link is real flexable, and if you pull gently on it, if the link is burned out inside, the cover will stretch.
You can also squeeze it for even feeling inside.
But if there is no obvious burning of the covers, then that probably isn't where the smoke came from.
Is the purple wire from the solenoid to the firewall still in good shape?
And I assume you checked the red battery cable all the way.
Are you aware of the web site that gives access to military repair manuals?
http://www.steelsoldiers.com/index.php?module=pagesetter&tid=1&page=5
And the place to get parts?
http://www.memphisequipment.com/
I am curious what truck you have. The 1008 Chevy pickup, or the 1010 ambulance.
1009 was a Blazer.
The 1010 has the same engine, but the alternators, and regulator system are much more complex.
The 1008 has a left and right alternator, Delco 100 amp.
The 1010 has a top and bottom alternator. Leece Neville's. And a battery isolator and regulator on the drivers fender area.
Van
