Truck won't start, and can't pinpoint why

[YerDaddy]

I like the fact that I can start the truck on less voltage with this starter than I could the Delco.

I guess that matters more up in the frozen North.

So does it give you any more trouble or is it working normally? The mag switch will go slowly like that as the contacts get crappier.

[Rev.Vassago]

No, it hasn't given me any more trouble (knock on wood).

[bob h]

Some of you guys are confused. Rev's Mutsu*****y has the magnetic switch (which some of you mistakenly refer to as the solenoid) mounted right on the starter to reduce the voltage drop of the longer wires if it were mounted on the firewall. The magnetic switch is, in essence, a relay.

...snip

A relay IS an electromagnetic switch... as is a solenoid. But, since you were nice enough to correct "our" terminology error... here is a starter SOLENOID installation guide from Mitsubishi's H/D site.

http://www.diamond-gard.com/docs/Sol...stallation.pdf

Guess you're gonna have to contact mitsu and ask them to correct their service literature?

[bob h]

You can jump the mag switch to rule out the key switch and mag switch internals. If the key/button doesn't work, jump the two heavy studs on the mag switch. If it cranks, the problem is the smaller amperage wiring ie the key/button system or most likely, the mag switch itself. Best bang for the buck would be to replace the magnetic switch.

If jumping the mag switch does zilch, jump the "B" (battery)(big red wire) terminal on the solenoid to the little "S" (start) terminal on the solenoid (where the wire comes from the mag switch). If'n it cranks now the solenoid and starter are okay. The problem is voltage drop in the wiring and time to break out the load tester and voltmeter.

If the starter does NOT spin when you jump the 2 large terminals, it also will NOT spin when you jump power to the little "S' or "Sw" terminal.

[still bullhauler]

just thought but did you check if the hot wire where it bolts to the starter, that nut can rattle lose, in about the time you say you had the starter replaced. it can get relly lose and catch nine out of ten times, with no trouble, just a thought, had it happen to me on a brand new truck

[allan5oh]

It's simple logic:

Turn the key to start, see if there's 12V to the starter relay(usually on the firewall).

Then test if the relay is clicking, and the starter is getting juice to start.

Most new starters also have a relay right on the starter. Check to see if it's giving juice to the solenoid.

So to simply say it's the solenoid because it works if you jump it is foolish. There are many possibilities between the key and the solenoid. The key switch, truck starter relay, and the relay on the starter that picks the solenoid. Or a broken/frayed wire anywhere in between.

The good news is key switches don't usually go, unless the truck is really old. Starter relays can go, and they're cheap and easy to fix. I'll bet cash the starter relay is working fine, as is the solenoid.

What I've actually done is put a couple of diodes in a few select spots, so if anything goes I instantly know what's wrong.

Another thing, does the starter have overcrank protection?

[Orangetxguy]

REV? What was the problem? Did you find out what it was? Did you get it corrected?

[Rev.Vassago]

It was the solenoid. A guy that I happened to save from hitting another truck this morning came over with a large piece of wire and helped me jump the solenoid.

Now the million dollar question will be - will Peterbilt honor the warranty if I can't reproduce the problem?

^^^^^^^^^

[YerDaddy]

http://www.diamond-gard.com/docs/Sol...stallation.pdf

Guess you're gonna have to contact mitsu and ask them to correct their service literature?

Aaaah, nope, it looks like they know what the IMS (magnetic switch), and solenoid is.

The problem is when you are diagnosing starting circuit problems and call the mag switch a solenoid when it is not the solenoid. Why change the names of things to create confusion. Call it what it is.

If you wanted your boy to feed the dog would you ask him to feed the chickens? No, you'd ask him to feed the dog!

Here's some for you to ponder:
automatic vs. automated
manual vs. mechanical
These confuse many a driver, et tu, Bob?

[Fredog]

Aaaah, nope, it looks like they know what the IMS (magnetic switch), and solenoid is.

The problem is when you are diagnosing starting circuit problems and call the mag switch a solenoid when it is not the solenoid. Why change the names of things to create confusion. Call it what it is.

If you wanted your boy to feed the dog would you ask him to feed the chickens? No, you'd ask him to feed the dog!

Here's some for you to ponder:
automatic vs. automated
manual vs. mechanical
These confuse many a driver, et tu, Bob?

so you just gonna let the chickens go hungry?

[jonp]

Did you happen to check on whether or not you have a light on in the truck? Like inside the truckbox that you cant see? If it stays on constantly you can run down the battery and not know it. I've had that happen in both a car (trunk light) and a truck (sidebox light). Could be why the batterys drained in the first place. You might try banging on the starter with a hammer. Might not work but you'll feel better.