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

I'm scratching my head on this one. The truck won't start at all. Won't even turn over. I replaced the batteries and starter about 4 months ago (PACCAR deep cycle batteries, and Mitsubishi starter). When I turn the key to start it, I get nothing but a single click. I spent the past few hours charging the batteries off the generator, thinking they were low. The gauge is reading 13.5 volts when I turn the key to the "on" position, and all the lights and accessories are working properly.

I'm thinking it might possibly be the ignition switch that took a dump on me, because I noticed the other day that I could pull the key out when the truck was running. Having never had to replace an ignition switch, I honestly don't know if that would cause this problem.

Any ideas on what might be causing this?

Sounds like the ignition switch could be a possability. To test and find out, you will need to crawl under the truck and take a jumper wire from the small terminal on the starter solenoid (which comes from the ignition switch) and jump it to the big terminal which comes straight from the batteries. This will engage the starter to verify it is still good and the batteries are fully charged. It could also possibly be a clutch switch if your truck is one that has to have the clutch depressed to start.

http://i44.photobucket.com/albums/f7...go/starter.jpg
This is a pic of the exact same starter that is in my truck.

So you're saying I should jump from the post on the top (on the solenoid) down to the post coming out of the starter itself?

do you have to push a button to start it? if so, it's the relay on the firewall,sometimes it stops in a dead spot, you can usually get it going by either hitting it with a small hammer or jumping it, if you dont have a button, then jump it at the starter as suggested

1. You know that little panel behind your clutch pedal that you kick all the time? Pull that off and swap your starter relay for another relay in the box, like your trailer light relay. If it works it should be as simple as replacing the relay.

2. If step 1 fails you, jump start the starter. if that works more than likely your solenoid is bad. Replace that.

3. If it is still being stubborn, replace the ignition switch. It is not unheard of but pretty rare in my experience that it would fail. One of my trucks is an 83' shaker and the key does not even stay in but it starts fine. I can only imagine what our pacar friends would charge you for an ignition switch.

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?

Have the solenoid posts checked Rev. What you just described was the problem I was having with my Cat starter last year. It turned out that the solenoid was bad. The Hot post was lose inside the case and was shorting out from time to time. Fire waiting to happen.

Can you make that happen for me? Please? :)

Is it that bad up that-away?

you're asking the wrong guy, rev is the fire expert

+1 :thumbsup:

Why does the title of this thread sound so much like,,,,,,,,,,,

"Help! I've fallen and I can't get up":lol:

First, be careful when jumping the solenoid that the truck is in neutral!!

The key should feed power to the small solenoid on the top of the starter, either diredtly or through a relay & clutch switch if equipped. The small one feeds the big one thats part of the starter. My guess is you heard the small one clicking.....

If you can pull out the key while the vehicle is running you sure the key isn't just worn?

...excuse any repetition, as I haven't read the other replies yet...


If the ignition switch is bad, you won't get the click under the hood.

All you need is a test light...

The click is usually the firewall switch which energizes the main solenoid on top of the starter body. The firewall switch has 2 large terminals; the first terminal is always hot, the second terminal should be hot ONLY when the ignition switch is turned to the crank position. So, if you turn the ignition to CRANK, and that 2nd terminal is hot, the switch is OK. ...that will lead you to test the starter/starter solenoid (let me know if you end up here).

If the second large terminal doesn't turn hot during crank, then you must check for fire at the "small" terminal of the firewall switch, if it is hot, but the large 2nd terminal is not hot (in crank position), then the switch is bad.

If there is no fire on the small terminal (careful, as there may be 2; a live and a ground), then the ignition circuit is lost, it comes from the dash switch or crank button (let me know if you end up here).

Does that clear everything up?

No, that would create a dead short back to the battery. You're looking to close the connection between the two large posts on the starter solenoid, usually done with a flat srewdriver.

If you jump the solenoid and the engine cranks; the starter motor is NOT your problem. If you jump the solenoid and the engine doesn't crank, then the starter is the problem.

The starter cable that is on that large post at the end of the starter motor is probably connected to the frame rail of the truck - ground.

They never have for me. They say that is they have to way of seeing that the part is defective when you bring it in, then it's not defective...

You may want to check to make sure all of the connections are tight. I had a driver who had a problem starting one of my trucks. He said he checked everything. I checked the batteries and found two cables were not tight. I tightened them down and they are working just fine now.

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.

In Rev's pic the top thingy is the magnetic switch, the progressively larger middle thingy is the starter solenoid and the big thingy at the bottom is the starter.

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.

And when this starter pizzes you off for the last time, put a Delco 42 back on! Mechanics like the smaller, lighter Mitsubishis and Densos because they are lighter and throw-away - just r&r. Delcos are still the better starter as far as reliability. They are just a big heavy pain to handle but cheap to rebuild.

This is how I got it started, but I also checked it with the voltmeter, and it was delivering a full load to the starter.

I originally replaced the starter because the Delco up and decided to ruin my batteries on me after I tried starting it, and it drained them within seconds (to the point that the battery terminals were melting). The Mitsubishi carries a better warranty than the Delco, and was comparable in price. And 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.

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

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?

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.

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

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?

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

^^^^^^^^^

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?

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.