Anemic starter

[Russell Reay]

My starter has worked fine for the four years I have had my car. I recently bought a firewall insulator panel. During installation I made sure that all screws thru the firewall that were needed for ground were, in fact, well grounded. These were primarily the solenoid bolts, wiring harness ground wire, and starter button ground wire. When pushing the start button, the starter would clunk and briefly groan, but nothing more. After removing and re-attaching all connections between the battery and starter at least three times, and buying a new battery though fairly confident I didn't need it, I removed the starter and the starter switch on top. Attaching good quality jumper cables to the battery terminals and to the starter case (pos ground), the jumper cable to the copper contact on top elicited a smooth spinning reaction from the starter, but not the excited hang-on-tight response I expected. I re-installed the starter and got the original clunk--not the typical click of a bad solenoid. All battery cables are size 00. I hate to rebuild the starter when the only actions I have made were to play with the connections. Diagnosis and recommended repair requested.

[Marshall V. Daut]

I had the same problem with a friend's Vicky a couple months ago. New battery, clean grounds, correct cables, etc. Still, the engine turned over slowly. I removed the starter and took it apart. The commutator plates on the armature were black from rubbing against the very tired brushes. I replaced all the brushes and cleaned the commutator plates with 220 grit wet-dry sandpaper. Then I used a toothpick to clean out the gaps between the plates, although not like cutting the micra on a generator armature. Just scrape out any gunk in the gaps that may affect operation r cause the plates to short against each other. The starter is easier to re-assemble than the generator because you can use the spring tensioners to keep the brushes up away from the armature as it is slid back into the case. After re-assembly, the starter spins the engine over as if it had a 12 volt battery! Try this procedure before panicking. It'll take all of an hour or two from start to finish.
Marshall

[Benson]

One more suggestion:

Yesterday I had similar problem.

Three month old optima battery.

00 cables.

Separate cable from flywheel housing bolt to the bolt which connects the ground to cross member.

Depressing starter I got a very weak Clunk almost like click. No starter and DASH light dimmed.

Long story short it was a bad crimp on the Ground cable terminal from the braided cable (POSITIVE terminal) to ground on cross member.

Earlier I had cleaned the both terminals on battery and where ground cable connects to frame cross member.

Also cleaned other NEG terminal from battery and other end of neg cable and terminal and the nut at starter.

To be clear.

1. Ground cable has clamp terminal (which was cleaned) at the battery end which in turn is crimped to braided cable.

2. other end of braided ground cable is then bolted to cross member.

The crimped junction at battery end was not tight or corroded.

Before replacing bad cable: Also after trying to start several times the terminal that is bolted to frame got HOT to the touch where it is crimped.



Also replacing cable increased cranking speed 25%.

[nkaminar]

A voltmeter can be used to chase down the problem. Measure the voltage from the one of the starter bolts to the ground connection on the battery when try to start the engine. There should be no measurable voltage. If there is then there is a problem with the ground somewhere.

Now measure the voltage from the starter switch terminal to the hot side of the battery while trying to start the engine. There should be no voltage. If there is then there is a problem with the wiring from the hot side of the battery to the starter switch.

Fix any problems with the hot side or ground side before proceeding. Do you have a good ground between the ground post of the battery and some point on the engine such as a transmission bolt?

Now measure the voltage at the starter switch terminal to one of the starter bolts while starting the engine. With a 6 volt battery the measured voltage should be about 4.5 volts. If it more or close to the battery voltage then the starter is bad and clean it up like Marshall advised. If the voltage goes lower than about 4.5 volts then there is a short in the starter or the battery is bad or the cables or connections are bad.

[Russell Reay]

Update: I checked the ground path with a voltmeter and got zero. I checked the hot path and the needle jumped to the LEFT. Checked connections for a rerun, and had same results. Disassembled starter on the bench and found brushes to be adequate for continued use (IMHO). Cleaned the commutator with 240 grit, but there was no cleaning the path between the plates- there is no depression--can't feel that the comm is anything but a perfectly smooth cylinder. Diameter is 1.532". Did bench tests per red book. Book says draw should be 50-60 amps. My meter only measures mA, and I didn't want to fry it. RPM test should be 4000 rpm, but it certainly did not appear to be that fast. Shaft appears to be perfectly straight, but there sounds like a little flaw on the shaft--one soft tick per rpm. Also, the neg cable got very hot while holding it to the copper contact. I anticipate a rebuild in my future, but I still feel I am missing something.

[Big hammer]

Sponsored Links (Register now to hide all advertisements)

Check the solder joint under the starter switch button, two heavy conductors join there, I had a cold joint that was intermittent

[rotorwrench]

I always start with easiest thing first or the last thing that was worked on prior to the problem. The OP mentioned the term solenoid. There is no solenoid on a stock model A. It has a foot operated starter switch. The switch can be disassembled to check condition but the first thing I check is whether I can crank the engine by hand. I would then check battery cables to starter and frame to make sure they are clean & tight plus terminal connection condition. The amperage has to get there or it's non functional. Removing the starter and bench testing would be after a start switch inspection. If the starter function has a jolting start torque with quick rpm the it should be good to go.

A suspect battery should be high rate discharge tested after getting at least 6.2-volts to start with. A good hot battery should turn the engine over with the headlamps on. They might dim some but they should still put out some light.

As far as starter condition goes, you have to check the resistance of the fields and the armature has to pass growler tests. A bad field or armature will not function well. To add about undercutting the comutator, you don't have to do that on starter motors. It's generators and low torque motors that generally need undercutting of the mica between segments. Starters have pretty solid brushes. Generators and light duty motors have carbon brushes.

[nkaminar]

I think you should take the starter and the switch to a repreble generator/starter shop or ship it to someone who specializes in Model A starters. It will come back in first class condition. If you still have problems then it will not be the starter.

If you still want to work on it yourself then view the videos in this link: https://www.youtube.com/results?sear...tarter+rebuild

[stevemclark]

Dimming headlights can show a bad ground too.

[rackops]

A while back, my starter got sluggish. The car still started, but it didn't seem as snappy as it once was.

After removing the starter, I discovered that a rag must have been left in the flywheel at some point (NOT BY ME!) I had owned the car for about a year by that point...so who knows what the story was!

[stevemclark]

I thought you had the starter out.

[nkaminar]

If you want to slow down your starter, perhaps because you have converted to 12 volts, you can wire a Model T Bendix spring in series with the starter. It can be on the ground side so you don't have to worry about shorting to ground. The spring will work as a resistor and inrush current limiter for the starter but any other devices, like the head lights, will not see it.

[Russell Reay]

Am still tinkering. I don't like to rebuild and/ or replace parts unless I know what the problem is. I have already installed a new battery and know the cables to be correct. I am researching the problem with no electrical connections except the battery, cables, solenoid and starter--no switches, fuses, etc. In my latest exam with the starter band off and the commutator visible, I grounded the solenoid as if to start it, and could see the armature turn a fraction of an inch and the cable to the starter and the starter switch got very hot! The voltmeter slowly crept up to 3+ volts. I am thinking that the starter's failure to spin is causing serious resistance leading to serious heat.

[nkaminar]

If the cable and solenoid are getting very hot then that is your problem. Bypass the solenoid and touch to cable from the hot side of the battery directly to the nub on top of the starter. 3 volts indicates that something is dropping the voltage and that something would be the solenoid.

I could be wrong, of course. Did you do a bench test of the starter while it was out?

[rotorwrench]

It should jump into a high rate rpm at application of power. If bearings are sloppy loose (worn out) the armature can rub the field pole shoes. If the bearings are free and rotation is easy then the field or armature have problems such as open or shorted windings. How much more evidence is needed to prove a problem?

[Keith True]

I'm a little confused about something.You talk about having a solonoid on the firewall,and making sure the grounds are good,then you talk about the switch on top of the starter???You have both??

[Russell Reay]

Originally Posted by Keith True

I'm a little confused about something.You talk about having a solonoid on the firewall,and making sure the grounds are good,then you talk about the switch on top of the starter???You have both??

The original switch is in place, but the plunger for foot start has been removed. The copper strip inside is bent to be in constant contact with the big copper button, and the neg battery cable comes from the solenoid. I just picked up a rebuilt starter from Tam's, and anticipate that will solve my problems

[Benson]

Originally Posted by Russell Reay

The original switch is in place, but the plunger for foot start has been removed. The copper strip inside is bent to be in constant contact with the big copper button, and the neg battery cable comes from the solenoid. I just picked up a rebuilt starter from Tam's, and anticipate that will solve my problems

Good catch Keith!

I suspect that when Russell removes original starter switch from the old starter he will find that the copper strip inside has been over heating and is blue colored and the "buttons" on both the starter terminal and strip are burned and have been arcing when you hit starter button.

Because the strip inside has been over heating due to poor contact (no foot pressure to make good contact) then the strip likely has no more tension .

If you (Russell) are going to use either old starter OR NEW ONE it would be best to take them to generator / starter shop and have the "BUTTON" on starter replaced with the proper stud, lock washer and nut. so cable from solenoid has good contact.

If you do not replace stud, the new starter will have same problem in short order.

That switch was designed to have the foot pressure applied to the copper strip to work properly!

[rotorwrench]

Ford started using a threaded terminal for starters beginning in 1932. I'd suggest converting it to a threaded terminal with appropriate insulators to use a solenoid. The 1932 model B clutch housing is different but there may be a way to mix & match parts to convert a B starter to an A but I've never tried it. It may be easier to just use the B terminal on the A housing. It will require a heavy duty soldering iron to replace it. I'm still wondering why a model A foot switch won't work.

[nkaminar]

I think Keith hit the nail on the head. Buying a new starter is not going to fix the problem unless the remains of the foot switch is eliminated as others have suggested. Or the solenoid is eliminated and the car returned to the original starter foot switch.

In my opinion, for what that is worth, the original foot starter switch is one of the charming things about a Model A Ford.