I have a 27 TT truck and it will not start with the starter. I have replaced the starter. The bendix will engage but will not turn the motor over. My hand crank will turn over the motor, so I know its not frozen. I as wondering if the bendix spring is weak ? Any one have any ideas?
Bad ground, by pass the switch, use some good set of jumper cables and try it directly to the starter, if it works then go backwards from there and find the problem.
I assume you mean that the starter engages but will not turn the motor over. I am also assuming you have a 6 volt system.
You will need a voltmeter. Beg, steal, or borrow one. With the ignition off, have someone push on the starter button while you measure the voltage from the terminal on top of the starter to a good ground point ON THE STARTER. You should get about 5 volts. If not you have other losses somewhere in the loop. Next measure the voltage at the battery while someone presses the starter button. If you get 5 or more volts at the battery, but not at the starter, you can assume the battery is good for the moment. A bad battery will measure 3 volts or less, or a bad starter will draw the battery down to 3 volts, but you said you have a new starter. Next put the voltmeter from the good ground on the starter to a good ground on the frame (scrape the paint away until you see bright metal). If you measure any voltage at all, you have a bad ground as Joe was talking about. Next measure the voltage from the positive battery terminal to the starter terminal. This should be low, perhaps 1/4 or 1/2 volt. More than that and you need a new or larger cable or new switch. Continue investigating to see where the voltage loss is coming from. Check the negative battery post to the frame ground. Check to see if the cable clamps at the battery are warm to the touch. If they are, you need to clean the clamps and posts. Keep working it and you will find your problem.
Thanks, Joe and Neil. Joe, I tried your trick real fast and it continued to engage but would not turn over the engine. I will check on my ground through out the week and see if I can solve the problem.
Do you have heavy 6 volt battery cables? If they are the skinny 12 volt cables then that's likely your problem. Unless you used a 12 volt battery with your jumper cables it is unlikely that you got enough voltage at the starter to make it work.
The repro starter switches are notoriously bad and could be the cause of your problem. You can order an M Farmall starter switch from O'Reilly Auto Parts and adapt it to your Model T starter mounting plate. You may need the extension that the T parts vendor sell. Some folks have adapted a tractor starter switch from Tractor Supply Stores.
The terminal post might be loose.
If you get 5 or 6 volts at the starter and it still won't turn over, you might have a loose terminal post, either top of bottom, as Kep suggested. Use the voltmeter.
I just got finished replacing my starter yesterday. The starter has been very slow to turn over the car for quite a few years. Those who remember me on tours remember I crank started my 26 Roadster almost every time. I swapped batteries with another T on which the starter worked very well. I replaced the ground strap and the cables and the switch. Still no good results. I just figured the engine was tighter than the other T's. Well I finally decided to get serious and took off the bendix. The starter would not turn idle. I then jumped the cables and connected directly to the battery and still nothing.
Well I ordered a rebuilt starter and placed it on the car yesterday. It works just as it should. The problem was not in the battery, the cables, the switch, nor was the motor too tight. It was the starter itself.
Glad to here that sometimes things are what they are...... ;)
<headbang> HEAR ....... <blush>
Seven out of ten used Model T starters I disassemble to rebuild have a failed terminal bolt to field buss bar connection.
Ron the Coilman
As Ron has shown, the connection between the terminal bolt to the field bus bar seems to be a weak link in Model T starters. I found the same thing when I took my starter apart. I sawed a slot in the top of the bolt to resist the torque with a screw driver when I tightened the nut.
Besides the terminal bolt problem, the other thing that goes wrong are the brushes. They wear out or they don't move freely in their holders. This causes the commutator to burn. Cleaning the commutator and making sure that the brushes are good and move freely in their holders usually fixes starter problems. I clean the commutator with fine sand paper or emery cloth and a solvent. WD 40 can be used as the solvent. Clean up all residue. If really bad, you can start by machining the armature in a lathe. Clean the slots of all metal filings. A little effort can save big bucks for a rebuilt starter.
Other things to check are the bearings and electrical continuity.