On my 1926 2 Dr. the starter motor begins to turn very, very slowly and then eventually speeds up and the motor will finally start. New battery yesterday. Old battery with full charge barely turned the motor over, but not fast enough to get it started.
Any suggestions.
Thanks, Bailey in SoCal
Is there a good ground to the starter motor? Sometimes, with painting parts separately, or excessive grease, dirt and gaskets with rubber gasket sealants, the path between the starter and the ground cable attachment to the chassis, is diminished. Try running a ground wire directly to the starter and see if that doesn't help. Jim Patrick
Measure the voltage to the starter motor and if low look for poor connections all along the circuitry; for instance a bad starter switch, loose connections, loose starter or poor ground connections. If none are found then
remove and repair starter motor. These are electrical devices and do wear and get dirty. If full voltage is getting to the starter motor then the starter motor needs service. There may be worn brushes, binding armature, poor contacts, who knows; remove, clean, inspect and repair.
It could be the starter itself but connections and cables come first. All obviously must be clean & tight. Are you using one of those braided ground cables? Those suckers go bad and there's no indication of it unless it feels warm to the touch or it actually smokes as mine did. Ground cable to frame connection should also be checked. Rarely, but it does happen, the engine itself might not have a proper ground to the frame. Don't ignore the connections at the starter switch or on the starter motor itself. This is the easy stuff but do it first. You could save yourself some extra work. No cables or connections should feel warm after a hard crank.
The most common problem I see in 6 volt systems is to small of a cable size. These cables are typically twice the size your used to seeing on 12 volt system. Boy it really makes a difference to have the correct cable size.
Most Model T engines will turn over with only about 3.2 volts being measured at the starter terminal and engine ground. That voltage and the voltage across the battery terminals must be measured with the starter engaged to determine the loss in the cables. The difference in the two readings will be the loss. If the readings are the same, the battery is tired.
Here are a few typical or common problems:
Most new repro cables are 12 volt 2 gauge cables.
New cables have the terminals crimped on.
New cables have no sleeves to protect the terminal from moisture and corrosion.
The original starter switch can drop a volt or two.
A bad original ground cable can drop a volt.
A new ground cable is also rated at 2 gauge.
The original cables were 0 Gauge and could carry about twice the amperage of a 2 gauge cable.
The starter can have a terminal that was twisted and unsoldered from inside the case.
A quick test for bad connections is to hold the starter switch down for a minute to turn over the engine and feel all the cable terminal connections. The bad connection will be very warm.
Lots of good comments and the big one easy to check is...does your starter stud wiggle! Most old originals have at some point in their life been overtorqued.
Don't dismiss an original swtich for a repro...if your voltage drop across the starter switch is huge, and the switch body has the bend over tabs holding it together...take it apart, clean it, and put it back together...works almost every time and most of these new repro's come with their own set of problems.
Finally, (and Ron will shake in his boots at this one) sometimes a 'get by' is just pulling the ring cover and using about 1/2 can of electro clean sprayed on the comm and brush seats. Not a fix by any means...car off, spray the starter end down, come back tomorrow. But sometimes just flushing crud and tarnish gives you enough to do a better trouble shoot as to voltage drops at each point.
This may be a dumb question but your description makes me wonder whether the starter or engine is the problem. Have you tried hand cranking the engine and found it very difficult to turn over? I wonder whether the engine oil has gotten very thick and making it difficult to get the crank moving. Sort of like cranking in the winter when it is cold. It may be that very viscous oil makes the engine very stiff and as the oil is worked it thins out somewhat. Sounds far fetched as a cause though.
Another WAG is perhaps the clutch is sticking and as the engine turns over it loosens up a bit. Maybe all that is need is a good oil flush and reload with a good 5w-30 grade oil.
Cecil....
Actually a very good point...sticky clutch plates. Easy to check...
Chock the front wheels, jack one rear on a stand, clutch/park brake stick full forward, then try starter...no hesitation...you got sticky clutch plates!
If sticky, could try to flush free by adding some kero or ATF, let it slosh, and do an oil change...or my way...let it run on the stand and keep jerking the stick to an almost stall and release, they usually let free...then I change the oil and add some ATF.
You guys nailed it. I was sure all the terminals were clean - they weren't. Cleaned all and everything turned better.
I used Cecil's suggestion to look for sticky clutch plates and that was contributing to the problem.
Many thanks to all.
Bailey