More starter questions

[Cary and Don]

Hi, 

After ready all the posts on the starter problems when the 6V92 is hot, we got to investigating the problem we were having with this.

There was a discussion about the fuel pressure switch and we thought we had come upon our cure. Yeh, right.  Our pressure switch on the fuel filters isn't hooked up.

We had thought it was a battery problem, but jumping the ten golf cart batteries didn't make a lick of differance.  Sit around about an hour and it would start right up again.

The starter and solinoid are only about three years old. So we got out the diagram and started taking a good look at the Magnetic start switch. Well. some butcher has been at it.  It is a replacement and doesn't look all that old.  The big question is, what did they do with that wire that is suppose to go to the pressure switch.  The wire they put on it goes over the transmission and disappears up between the air bags.  When checked, it had a very weak ground.  So we thought if we added a good ground to the post all would be good.  No luck, it didn't start at all.  So we took the wire loose and got the same results.

Logic would say the pressure switch is normally closed, giving it ground.  If that was the case, adding a ground to the terminal should have let the starter engage.  If it was normally closed, taking the wire off should have let the starter engage.

We are trying to avoid another wait in a reststop hoping it will start in a half hour.  It always starts when cold. It spins fast and starts right up. It never grinds, groans, or just click. All or nothing.

We are hoping at this point that wire is getting hot and causing something to kick out somewhere.  Traveling on hope is a little scarey though.

Don and Cary
GMC4107

[Kristinsgrandpa]

Could you try cooling the starter with a little water to see if it helps the waiting period.

I had a 78 Ford truck with the same problem, the starter was only a few months old. A friend asked me where I got the rebuilt one that was giving me problems, I told him Autozone and he said they were junk and to get rid of it and get one at NAPA. I did, and had the truck for 3 years after that with no starter problems.

Pouring water on it to cool it was the trick till I replaced it.

Ed

[Fred Mc]

I had the same problem. Start right up when cold but would only groan when hot.

What I discouvered was that one of the 8 D batteries was shot. I replaced the 8D's with 3 -950CCA batteries. Two was marginal but I could get a couple of starts when it was hot but 3 works fine.

Having said all that I "THINK" that there is also a problem with the starter even though it was a rebuilt a couple of years ago. An old retired mechanic told me he had the same problem once and that the starter armature didn't have enough clearance so he machined 5 thou off the armature and solved the problem.

I have read before that not all "rebuilt" or even new starters are created equal.

Fred Mc.

[Don4107]

Don,

Next time it won't start make some quick checks.  First try the rear controls.

Be safe and remember, it can decide to start at any time.  Be careful please. 

The large cable to the solenoid from the battery should have constant 12 volts.  Use a test lite to check at the starter solenoid with the tip of the lite on the stud to confirm that there is a good connection while someone holds the switch in the start position. 

Next check the smaller terminals on the solenoid when someone moves the start switch to the start position.  You should have 12 volts to one of the terminals when in the start position. 

If you have both these voltages when trying to start it then the problem is most likely the solenoid the starter or a bad ground for one of them. 

If you have both voltages and the solenoid is not clicking suspect the solenoid. If the solenoid clicks check the large terminal that feeds the starter.  If it does not give you 12 volts while the solenoid is engaged suspect the solenoid.  If it goes to 12 volts when in the start position suspect the starter.

If you don't have the proper voltages at the solenoid then the problem is up stream from there.  There is a relay that activates the solenoid that works basically like the solenoid.  It should have three connections.  A constant 12 volts with the run switch on, a terminal that has 12 volts on it only when the start switch in activated and the third should be hot when the start switch is activated.  It feeds the 12 volts to the small terminal on the solenoid.  It should also click when activated.

Make these checks and let us know what happens.  There are other things, but try these first.  You can bypass both the relay and solenoid with a jumper or remote start switch but you have to have a pretty good idea what you are doing. 

Good luck

Don 4107-501

PS. Rereading I see you mentioned a 6V92.  Do you mean yours is?  If so, is it mechanical or electronic?

[Cary and Don]

It's mechanical. 

This seems to only happen when we have been on the road awhile, never at home.  That would be just too convienant.

The next time we go out, we will have some jumpers made up to reach outside the engine area.  That way we can try and bypass the magnetic switch or the starter solinoid.  It will be a lot easier to hold testers on the terminals outside the compartment too.  Don't want to die by fan blade, right?

Don and Cary
GMC4107

[compedgemarine]

"I have read before that not all "rebuilt" or even new starters are created equal.

Fred Mc."

this is true. on many rebuilds they just clean the armature and replace the brushes etc. on some they do not change the bushings/bearings at the ends of the armature. if the tolerance in the ends is too loose the armature can bind and drag, this usually only happens when they are hot and all the metal has moved around. had this problem years ago on lower cost rebuilds. some times it is worth the extra cost to get new parts that havent been abused by someone else prior to the rebuild
steve schmidt