Last week my 1972 98 455 (points ignition)began to have a starter failure. Slow labored crank. Try again and crank normal but hear the bendix kick out.

Napa reman starter only $36 so I get one. Not sure what part of it was reman because it looks new.

Install starter and it starts great. Sounds good. As always the engine fires off immediately (so quick can hardly release the key fast enough) and idles smooth.

Runs for 10 seconds and shuts off just as fast. Try again. Same deal. 10 seconds and off.

Thought I got a wiff of hot plastic. New starter smell maybe? Check connections, all good. Try again. Runs 20 seconds and shuts off.

Sounds like ignition as it is instantly off not stumble off.
But... fuel is lower than I ever had so add a few gallons and check for accell pump squirt. Nice it's good and strong.

Starts, runs, shuts off.

Go to check voltage/power at coil. Turn key to run and before I can get to the coil the wire from ignition switch to + coil insulation is smoking.

I read on here (MDchanic points sticky etc)and other sites but see nothing like it.

 

Check the bypass wire from the starter solenoid to coil+ for a short.

 

^^^This. It is easy to pinch this wire while installing the 800 lb GM starter.

 

Going to drop starter tonight and check. If the bypass only has power during crank not sure why it would cause resister wire to overheat with key in run or cause ignition shut off after start.

 

Because if its shorted then the coil will be connected to ground. It probably started as a pinched wire lightly grounding which is why the engine turned off. Then developed into a hard short to ground. The ignition circuit is not fused so the end result is roasting the wire.

 

Because the bypass from the starter and the resister wire are connected together at the coil. If one grounds, they both ground.

 

You bet me to it.

 

Thank you all. Appreciate the help.

 

Problem solved.
Thou the bypass wire was not pinched or touching any ground that I saw. All connections checked out and that wire runs neatly and cleanly up to coil.
I disconnected it at the starter and secured it out of harm.

Fired right up and ran great. Down the road and ran it for 20 minutes. All good.

I'll cut open the short section of harness it runs in at firewall and check for a problem but at this point suspect a defective solenoid.

Thanks again

 

It can't be the solenoid as its still operating as it should. I'm going to assume there is/was a problem with the bypass wire. You need this wire if your running points.

 

I will open the harness and inspect or replace the bypass wire but for clarification isn't the bypass just to assist starting (cold weather etc) and then out of the picture after that?
A least with the disconnection now I was able to verify the issue is in that circuit.

 

The bypass wire is to supply full battery voltage for starting purposes only. Trying to start the engine through the resistance wire can be problematic creating hard starts. How the circuit works is when the starter is engaged a disk inside the solenoid acting like a relay closes a circuit between the battery lug and the small R post to supply full voltage to the coil+ terminal. Since the car starts and runs fine with the wire disconnected that rules out the solenoid as the issue on its own. It may have been the terminal on the end of the wire laying over the solenoid mounting screw and/or shorting somewhere or the wire could have been pinched. If you want you could leave that wire stowed and run a new one along side of the harness to the coil.

 

I suspect the copper contact of the R terminal inside the solenoid cap has turned due to improper instalation when being assembled or over tightening of the nut on the R post either from the factory or during instalation. It may be touching ground inside the solenoid where the solenoid cap attaching screws thread in. If a parallel wire is run and it still happens then it is in the solenoid. If you change the starter or solenoid, take the solenoid cap off and take a look inside.

 

Re manufactured starters are of notorious low quality.

You probably have a low compression starter....do you know how to tell the difference?

 

Doesn't that disc rotate on its own so as not to burn a single spot. There is a high current potential inside that area of the solenoid to the extent that serious sparks, smoke, and damage would be the net result of a short to that post because it would also include the big battery lug connection.

 

With the key off I would check for a connection to ground on the bypass wire and on the R terminal. Possible the contact for the R terminal only contacts ground after the solenoid drops out? Doesn't make sense, but a meter would help.

 

Eric, I am refering to the small bent stationary contact that is attached to the R terminal on the underside of the cap and not the large round movable contact. This R contact only touches the large round contact when the starter is cranking and supplies 12 volt during crank. If this contact is broken or twisted and touching ground under the cap the wire to the coil will be grounded and would supply a ground for the resisted ign wire. If the wire from the R terminal is removed and has no signs being grounded from the starter to the coil and the car runs when this wire is disconnected from the starter it leads me to think the ground in this circuit is in the solenoid .

 

Possible, its worth a check as Patrick suggested in post 16. I also agree with him, its highly unlikely as its just a stud in a phenolic cap.

 

I had this exact condition years ago on a 71 442. It would intermittently shut off. some time four or five times on one trip and some times not for four or five weeks of driving. It drove me nuts. It turned out to be the solenoid R terminal was loose and would move just enough to short out. ~BOB

 

$36.00 for a starter makes me wonder about the quality. A delco solenoid alone would cost about that much and a high quality aftermarket solenoid would eat most of the 36 bucks. For 36 bucks (phenolic) might be spelled (plastic.)

 

Hopefully with all the suggestions the OP can find the cause and post results.

 

I have not had the time to investigate further yet.
Bypass wire disconnected at solenoid has solved the problem so I will R&I starter again.
As far as over tightening the connection that did not happen during install but may have in production.

Starter looked to be good quality. Cheap price was due to an inside deal as I am "in the business".

 

Figure this out yet?

 

Have not pulled starter back out yet. I will update when I do maybe this weekend.

 

I'm looking forward to the forensic autopsy results also. It seems the R wire had to be grounded somewhere either in the harness or under the solenoid cap. Good luck.

 

I'm betting in the solenoid. Removing the wire from the terminal eliminated the problem. If in the harness it would still be grounding.

 

I opened harness and checked by pass wire. No chaffed, cut, pinched or short found. Pulled starter to check replace solenoid. While doing so smashed the cap off it. Replaced solenoid, reinstalled and had no crank no click.
Nothing.
Checked for power at switch terminal in crank position. Had power. Pulled stater again and bench test.
Dead.
Took starter to AZone and funny it tested good but never even spin the motor.
They had one there and tested it. Passed and spun.
Bought and installed it with by pass hooked up. I would have rather ordered a Delco or something but really wanted to get this moving.
Starts great, runs great.
NAPA starter faulty solenoid and then failed motor.


Thanks for all the help.