I just purchased a 1930 Model A with the original drivetrain. Car started, drove fine, was able to drive onto trailer and around a parking lot. The last time I tried to start it i just got a kind of hard clunk and now nothing. Have checked/redone all connections, redone and wire brushed the grounds, removed and wire brushed the starter switch, bench tested the starter and it spun great, put it back in the car and nothing. What am I missing? Any suggestions? Car has been converted to 12v. Any help would be greatly appreciated.
What is the condition of the bendix like? I have had a broken spring & a broken bolt at times, worn key which the end dog fixes to. Have a good look there. Is there power to the starter terminal? If so is there enough power? - bad earth?
It could be stuck in the flywheel maybe pop it in gear and rock it back and forth maybe it will unstick
Like Outback said, bad earth. Check the surfaces of the starter to the block, should be clean and tight. Check the battery ground to the frame also.
With the starter in place, try jumping directly from the battery to the connections on the starter. That way you exclude the cars wiring and switches. If it cranks, you have a wiring issue.
Bad ground. My Model A does this from time to time because the connector can’t tighten fully onto the negative post. I just wiggle it until it works.
Did it come with "Hand Start Rod "" Just make sure in Neutral & leave hand Open on up stroke so you dont get a broken arm !! But I will ***ume you will try all above.
Having owned Model A's since 1968 I would bet that the Bendix might be bad or the ring gear is worn causing the starter to jamb. A bolt might have backed out of the Bendix or the spring could have broken. The starter is held in with three bolts. I would loosen the bolts and try to back out the starter and see if it is jammed. You can inspect the ring gear with the starter out. I'm betting ring gear wear.
Since you said you removed the starter and it spun on the bench I would pull the plugs and see if the motor spins over by hand. That clunk could have been anything but i would want to know if the motor jammed.
I ***ume you have the retard lever up? Trying to start in advanced position can bend the armature shaft
Thanks for all the responses, I think its a ground issue as well, had an old tractor do the same thing once. But after going over them all I thought I wouldve sorted it. Maybe need to start over on them. with the car in 3rd I can easily roll it and turn the motor over so I really dont think anything is stuck or jammed. The bendix looked good to me, but im a novice so my opinion doesnt mean much.
Easy to troubleshoot with a digital voltmeter. Connect voltmeter ground to the ground terminal on the battery (you may have to use a jumper wire). Connect voltmeter + lead to the battery connection on the starter. Have someone step on the starter ****on. The voltmeter should read 9.6 volts or above. Now move the voltmeter + lead to the starter case with the starter ****on still engaged. The voltmeter should read no more than 0.2 volts. Note that you must have the starter engaged during these tests. Results: less than 9.6 volts at the battery connection - you have a problem with either the battery or connections to the battery. Results: more than 0.2 volts on the starter case - you have a problem with the starter ground or ground connections to the battery. Results: 9.6 volts or above at the battery connection and less than 0.2 volts at the starter case - there is a problem with the starter or the contactor that is engaged with the starter rod.
The "hard clunk" you describe is the Bendix locked to the ring gear. As I originally suggested, remove the three bolts and you can easily prove that its not electrical.
If you read the post, he said that he pulled it out and bench tested and that it was fine. He had an issue when he installed it back into the car. I had the same problem on my 31 sport coupe. Unbolt the battery cable bolted to the center crossmember. Take a wire wheel to both sides of the metal AND the cable. That should fix it!
Ill plan on going back over all the grounds this evening when i get home, thanks for the help/suggestions. Hopefully Ill be reporting back with an all good.
the Model A bendix is awful with several failure points. Use a newer version, ebay, $25 for the last one I got for my avatar, but they last for many years, price has probably gone up
That ****er's toast!! Why would you want a Model A that won't even turn over???? Ship the sum***** to me (leave the starter like it is, just put the signed ***le over the visor) and I'll give it a decent burial. Damned Model A's anyway!
So I took both grounds loose and wire brushed both the terminals and the car surfaces. Also pulled the starter again and wire wheeled the face of the starter and the bell housing. Still nothing. I byp***ed the starter switch and ran a hot cable right to the terminal on top of the starter. It has a little wiggle to it, barely, is that normal? I got it to almost turn over a few times. Just a small grunt. Any suggestions at this point?
So the starter will turn the engine, but barely. Have you done the voltage tests suggested? Is there at least 9.6 volts at the starter when it tries to turn? That simple test will point you what to do next. The other option is to do a lot of random things and replace parts.
That will be my next test. Waiting on the wife to get home to help me, I don't seem to have enough arms. I was able to get it to crank well by byp***ing the starter switch and going straight to the starter post with the battery wire. Makes me think it's in the switch but it looks so simple I can't think of anything to cause the issue.
I just did that test, I have 12.8 prior to pressing the pedal, it drops to about 12.6 when pressing the pedal. I appreciate all the help from you guys.
Those original foot switches are really simple. Pull it off and look it over closely.... IIRC, there is a contact arm that when pushed connects the power to a stud within the switch. The contact or the stud can be errored to the extent that they won't touch. The stud can be removed and turned 180* to provide a new contact surface. I haven't looked, but I'm sure you can find a cutaway drawing of the switch online. Good luck!
Agree with 28phonebooth, you have only really scratched the surface by checking the bendix. But checking all connections, in the dash and in the "box" was a smart move. These starters are super easy to dis***emble, clean, and re***emble. Pull up the brush springs with a pick and they'll slide right out before getting into the case(literally two nuts). I clean up the commutator and between the poles, the surface of the armature, and even down in the field windings without disturbing the enameled windings of anything. Clean the grooves of the commutator so there is no bridging with built up brush dust. You could do all of this with simple hand tools in about an hour. I wouldn't use brake clean or anything that might dissolve enamel wire coating. Just do any cleaning by hand. The switch is really simple - you'll be surprised. I probably have a few but they really just need to be cleaned up - not necessarily replaced. There is a fiber washer around the post, in the body, to isolate it from ground but otherwise it, and the starter, are completely intuitive to work on. I'd want 13v+ if I was having issues. People have also "improved" the short, braided ground wire with "modern" stuff but somehow that doesn't mean "better" and you can fight a bad ground forever! Shooting the parts cannon at a model A is futile IMO. Use the old stuff!
What kind of voltage do you read if you move the voltmeter probe to the starter case when the starter is engaged? If it reads over 0.2 volts your ground is bad. If it reads 0.2 volts or less, the problem lies with the starter. The fact that it only drops to 12.6 on the positive side points to either a bad ground (test I just outlined) or a problem with the starter or the starter switch. A good starter with a good ground will drop the voltage to around 10 volts and the engine will turn over.
When I jump the positive lead to the starter housing I just get .02. It also doesn't change whether the starter pedal is engaged or not. I have wire wheeled both contacting surfaces in the starter switch. Finally not 100 degrees here for the first time this week so hoping to get it sorted today. We'll see.
That test means your ground is good, the problem lies within the starter. If you energize an electrical component and it has close to battery voltage available to it and no more than 0.2 volts on the ground side, but it still doesn't work; the component is bad. However, the switch on top of the starter could be the culprit. It is in between the positive terminal and the starter. Might want to take that apart and inspect it.
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