350c 1976 starter issues

[tnt.lee]

I have a 76 350c and Ive been trying to study up on starter issues. I hired a fella to change my starter a while back and he removed it and we never got around to installing the new one due to a health issue in between then and now. I installed the new starter and had it bench tested as good. Once in the machine and trying to put unmarked wires into place I was left with two smaller terminal light brown and dark brown wires left undone. I used a voltmeter to find the plunger switched start wire and have it connected to the start terminal of the selenoid. The result was not even a click. After reading other similar problems I would like to ask...Do you have to have 2 batteries in the 350c to get the starter to turn? I assume the starter itself is case grounded..I am stumped..

[Jim B]

Welcome to the Board. Sorry to hear you are having problems.

I don't know you or your skill set. Please accept there is no intent here to offend or put you down in any of my questions or suggestions. And safety first, please confirm your machine is in neutral before working on it. Now, some questions for you, since we aren't there to see for ourselves.

1. Have you confirmed it is a C series by the serial number? I ask as unfortunately many are sold as Cs, when they are not and it can make a difference at times.
2. Do you have the Operator's Manual and Technical Manuals for your machine.
3. What caused you to replace the starter?
4. What brand and model starter is your replacement? Did the solenoid come mounted on it or was it a bare starter?
5. You say you had the new starter bench tested. To clarify, is it truly a new starter or a starter new to your machine (used, rebuilt, etc.)?
6. What group and size rating is your battery?
7. You said you found the start wire with a voltmeter. I understand this to mean you turned the key to start, or pushed the start button, and that wire had 12+ volts at the solenoid. Is that how you did it? That method would indicate the switch and neutral switch are ok.
8. If you use a jumper to momentarily touch between the battery cable stud on the solenoid and the small S terminal will the solenoid click or engage? This would be how it should have been energized during a bench test. If there is no click or engage during this check and you have 12+ volts at the battery cable stud, I would suspect the solenoid is bad, provided the starter ground is ok.

One battery should start a 350 in most conditions. The starter is grounded through its mounting. It should ground ok unless the mating surfaces are badly rusted or coated with heavy paint or other material reducing metal to metal contact. I do not have a 350C manual with a electrical schematic. I would expect the battery cable and a wire that supplies wire to the switch and accessories would be on the large solenoid stud. The lower stud connects to the starter motor. One small terminal (usually the one clockwise from the battery cable stud) is the start terminal and engages the solenoid to turn the starter. The other small terminal is for providing full voltage to the coil of a spark ignition engine during starting and is not needed on a diesel.

Clean the battery cable connections, battery post ends and where the ground cable attaches to the crawler frame. With a voltmeter check battery voltage at the battery. Check voltage at the large post of the starter. With the voltmeter on the battery try to start and see what the battery voltage is. Do the same at the starter. Watching the voltmeter while trying the starter will show if the load causes the system to lose power. It is possible for an circuit with no load to test as having power but lose it when load is applied. Those are voltage drop tests and can help find out if the battery is weak or if a cable is bad internally. If you touch a cable connection and it is warm or hot after trying to turn the engine that is often a sign of a bad cable. HTH
Jim

[tnt.lee]

Thanks Jim
Im a retired Aircraft mechanic,
The starter is a new Wilson gear reduced. I Had it on the floor and used my bump switch and cables to bench test it.
It is a confirmed 350c. After further poking around last night I confirmed i have the right wire from the push switch down to the start on the selenoid.
I had someone push the sw and confirmed with test light..but i havent checked the voltage drop. I only had one 750 cca battery in it. I was going to return to my camp with 2 1000cca batteries today and its bloody snowing and raining. I am really thinking it is the selenoid but want to try with the new batteries. I have had this machine for a while and its been sitting since my heart attack two years ago. I really look fwd to fixing it up shes pretty rough but she was a good runner when i parked it. THe old starter was intermittent was the reason i changed it selenoid was only clicking.

[Jim B]

One 750CCA battery should have tried turning it and if it had been running regular would have started it I believe. It does sound like a bad solenoid, but you said it worked on the floor before installation. Has the machine been setting inside or out? I hate to ask this but Is there a chance the engine has stuck? Did you by chance try turning it with a bar while the starter was off?

[Lavoy]

If one 750CCA battery won't turn it over, the battery is not the problem. Even if you pour the amps to it and it works, that is just masking an underlying problem somewhere.
Lavoy

[LeonardL]

As Jim has pointed out here and in other posts... if you have a master battery disconnect switch... be sure and check that!! Those things have tripped me up more times than I want to admit to. Usually it will be a bad ground associated with the ground strap installed from the factory or it will be that master switch. I would ground the engine directly from the negative post on the battery. That way you know you have a good ground. If you have a master switch, then I would bypass it. Like Lavoy pointed out, you can have all the amps in the world and still have a weak or non functional starter. Those switches are famous for letting just enough voltage through to make you think everything is good. As he pointed out you can force more amps through but it will just mask your real issue.

And just for information purposes only... Your original starter was probably no more than a bad solenoid. Those Delco solenoids are famous for just clicking after they have aged some. There have been more starters replaced when all they needed was a cheap solenoid replaced.

[tnt.lee]

thanks guys chased it down to selenoid post. Changed it out rolls better than ever. Don't know why it checked out before. Got bigger fish to fry now. Someone welded the crossmember and found the weld broke. Wish I could figure out how to post pics. We rewelded it and it just broke next to it. So i guess we gotta figure out what rods to do it with. Joys of being in the bush.

[dtoots1]

There are several posts in regards to being able to post pics on this site....

1. At the bottom of the Board Index...is the Q&A forum.....in that you must look for "Pic Server Instructions" and read all info.

2...NO ONE can upload pictures direct from cell phones at all.

3...you also need to add your location to the "Profile"...access is found in the drop down box where you login to jdcrawler site.

4...In order to have access to upload pics to the pic server....you must email Lavoy at postmaster@jdcrawlers.com, and include your chosen login and password for the pic server.....he will advise when registered.

[CPV]

Hi, TNT.Lee. Did you get the matter resolved? Just started having the same issue with my 350cb. Was curious. I am just starting into this process of diagnosing problem, following from the battery, battery switch, neg. ground etc and onwards.

[Jim B]

tnt.lee may see this and reply, but his last post was the one above where he says he tracked it down to the solenoid post.

Some things to check. Load test the battery(s), clean both ends of the battery cables and where they connect. Does it try to crank the engine? Check voltage at the batteries, then at the starter to see if it is the same. check the voltage while cranking to see how much the starter pulls it down. If you touch the ends of the battery cables immediately after cranking a cable that is bad internally will be warm to hot. If you have a battery disconnect switch hook both cables to one post to bypass it as a test, I have seen them go bad. Be sure the crawler is in neutral and try jumping from the solenoid battery cable terminal to the small S (start) terminal of the solenoid. If it turns over that way it is an indication the power wiring to, or the start circuit from the switch has a problem.