M1009 No start

[combatmech]

Howdy all,
Had been driving the truck for the last week with no problems. Let it sit for a week or so and it still cranks right up.

Changed a battery prior to having this problem.

When you turn the key to start, the wait light does not go out at all. When you crank the engine, it makes a "shuddering " kind of noise. checked the voltage of batteries when in the start position, getting about 15V. (should be 18-22V)
The troubleshooting book points to a starter......Not so sure about that.
When all this started, turn the key to "on", I was getting a lot of noise from the glow plug relay....went ahead and changed it. The new one does " click ", still no start and no crank. Any suggestions????

 

[mistaken1]

Bad battery?

 

[combatmech]

I tried to jump it with same result. The only thing I can think of is the battery I replaced is a commerical battery. Same volts/amps as the old one. Both batteries are showing 12.5 volts each.....

 

[Ken_86gt]

You need load test the batteries, take them to AZ and they will test for free, easier and cheaper than immediately changing the starter. Sometimes a bad cell in a battery can make it look good until it is under load. Clicking relays are usually a sign of low voltage. Could be a bad connection with your new wire.

 

[combatmech]

One other note.....when you turn key to "on", I dont hear the click from under the dash. Normal lights come on, "wait" light stays on.....still no crank. When the key is turned to "start", you can see the engine turn very slowly.

 

[Ken_86gt]

Also check the ground wires coming from the front battery, make sure all of the connections are tight, at the body and the wire that goes to the engine block.

 

[southdave]

Check your grounds, you may have rattled somthing during the exchange, take some jumper cable hook to neg side of bat set ground it to motor. this may elimitate this possidility. check the grrnd cable at the reat of the motor by the fuel filter

 

[combatmech]

Thanks all....I'll check everything again before I start throwing money/parts at the problem.
After that...she's goin on the auction block. It's a great truck, has the standard rust....great drive train and engine ( when it runs ).....Dont have the time or money to fix everything.....
Thanks again guys!!

 

[combatmech]

One more thought,
i bought a regular civ car battery to replace the old mil battery. it's a 12v 1000 starting amp battery......Does it really matter?

 

[Ken_86gt]

As long as it is greater than 600 or 650 amps you are fine. A 1000 amp battery is a great choice.

 

[combatmech]

As a last resort, I swaped batteries from front to back, the truck cranked over but still no start. Had both batteries checked, one dead, one needed a charge. Thanks for the help dudes....
BTW, I had a relay fall from under the dash right after I bought the truck. With all the trouble shooting I did, found out what it is..... #2 Gen relaly.....

 

[BIG_RED]

Hmm.. that's no good. Could be a spare or something.. hope so. Cause if that's your relay - that could be a problem. When you turn the key to "run" before starting, do both Gen Lights come on?

 

[combatmech]

No...turn the key and only Gen1 light comes on.....When I plug the relay back in, Gen2 light comes on...and then after starting, stays on.
I bought it last July....when it fell out, everything still worked, or so I thought. I looked at the troubleshooting for that relay....it says that the relay is bad.....I suspect something else as well. I'm thinking one or both Gen's are bad. When I load up the electrical system while the truck is running, ( lights, heater fan ) Gen1 light comes on very faint.....

 

[BIG_RED]

My Gen1 light faintly comes on too.. but I can't tell unless I'm i the middle of nowhere and all the other lights are off. My understanding is that the lights in the dash actually supply the current needed to excite the alternator. When my Gen1 light burnt out, I had to rev the engine to get Gen1 to kick in. I imagine the Gen2 set up is similar. One dead battery due to no charging would make sense for your situation in my mind. I'd direct my attention at sorting that out first. There are great wiring diagrams available on this site for how the alternators are wired up. I think they're in the TM's (technical manuals is what I think that stands for) and could be found on the resources page.. Although I might be mistaken. A more seasoned site-user could help you locate them. Worst case scenario, I'll send you mine (once I find em). Good luck.

 

[combatmech]

I have the CUCV TM on CD....I have been using it to locate stuff. As for the trouble shooting trees.....I wouldnt totaly go by whats in there.....The wiring diagrams are pretty good though

 

[woodyNla]

When my Gen1 light burnt out, I had to rev the engine to get Gen1 to kick in.

Interesting. I have the same issue with this 1031. Guess I need to check the light and contacts.

 

[BIG_RED]

Agreed CombatMech, the wiring diagrams are great.. other stuff, not so much.

WoodyNla, you might want to look up how normal chevy 3 and 4 wire alternators work if you are having trouble. I think the chevys work the same as almost all car alternators, and generally have lots of info online about them cause so many people build up GMs. I am not a pro at all, but looking up how the alternators work (from a wiring/regulating standpoint) I was able to change things around in my truck and fix all my charging issues. I'm also assuming a 1031 has the same big GM 100 amp alts as my M1009, but I am new to MVs.. and don't even know what a 1031 is . My experience is with my M1009 and other civvy trucks. Civvy truck alts are all pretty similar, at least the ones I've come across. Good luck, and if its like a M1009, maybe I'll be able to help you out.

 

[combatmech]

Both alterntors are bad.....#1 alt sounded like it was gonna come apart while on the test bench. Go figure.....

 

[CUCV85]

Both alterntors are bad.....#1 alt sounded like it was gonna come apart while on the test bench. Go figure.....

I hope you made yourself a diagram
as to how to re hookup these alternators.
They are identical Alternators but hook up differently,
the drivers side being normal
and the Passengers side GEN 2 adds 12 volts
to the system to put out 24 volts. Actual (28 volts).
These 100 amp alternators have an isolated ground,
plastic washers inside.
During rebuild make sure no one discards the original setup!
The going rate is 100-125.00, some attempt it themselves.
Take it to a reputable person/shop.

 

[BIG_RED]

I second that - make sure they know the passenger side alt must have isolated ground. When you get it back, might be worth checking for continuity between the neg output terminal and the alt's case with a multimeter - just to be sure.