Starter troubles

37 Cab

37 Cab

Well-known member
Looking for some input here.. When I try to start my car, I hit the start button and it will not crank. The starter bendix does engage to the flywheel just won`t turn. If I let go and hit it a couple times it will turn over and start. Hot or cold makes no difference. Has a new starter from early ford store. New battery. 2 gauge positive cable. Strap type cable to body. Additional ground cable from frame to engine and one from engine to body. Charging volts are 7.2 at 1500 RPM. Cranks faster when hot but not before hitting the button a couple times to get it turning. If I just hit the button once like I said.. Starter Bendix engages but will not turn over.. (like dead battery) Once it starts cranking it cranks normally.. Missing something here..
 
What do the teeth on the flywheel look like? Did this just begin after replacing the starter or did you replace the starter because it acted like this. I would use heavier cables like 0. Have you tried a different solenoid? Check the grounding on the starter button in the dash, it needs a good ground too.
 
When I first restored my car, the cranking sucked. I had the starter tested and it was fine. I was using a 6v Script battery (won't do that again). I added a heavy wire from the bat to the engine and that helped but I still wasn't impressed. A few years ago I got a 6v Optima and with the wiring unchanged...made a huge difference. Was told by the old time electrical shop that tested my starter that with 6v...good cable connections are critical. New battery doesn't always mean a good battery...I'd start by having that tested.
 
Make a jumper wire and attach it to the small post on the starter solenoid and take the other end and ground it to the engine . Also make sure the cables are hooked up to the proper post on the solenoid,it does make a difference. It could be a bad solenoid also.
 
Flywheel looks fine. It was doing this before I put the new one on. I really want to stay with a conventional battery since it is on the firewall and I don`t want the box that hides the optima. Solenoid is below the battery and the cable closest to the engine goes to the battery. Battery tests good as well. Gotta be a resistance problem somewhere. I will check the button ground tomorrow. Thanks for the input.. will advise.
 
I'd kinda like to know what car you have. Also since the solenoid is critical, has it been changed. You have mentioned what the engine do not do but not what is does do when the starter button is pressed. Sounds, noises, that type of hint.

Incidentally, it is easy to have an Optima battery without a hokey case to hide it.
 
Sorry.. It is a 37 Cabriolet 6V positive ground with stock 21 stud engine. Solenoid has not been changed. Like I said.. Bendix engages flywheel but will not turn engine. Just a clunk.. Like a dead battery.
 
Comments regarding the starter button are valid. I had to file the rust off of the hole where the starter button mounts. But if it is the starter button, you will not hear the solenoid click. If it clicks but does not crank, the solenoid is a prime suspect.

Sounds very much like a solenoid with contacts that have become burned and pitted, making intermittant or high resistance contact. Put a voltmeter from the battery terminal of the solenoid to the starter terminal. It should read battery voltage. Then have someone push the starter button; when the solenoid clicks, the voltage should drop to near zero. If it does not, the solenoid is not good making contact and must be replaced. When you hit it a few times it can break through the crud to start cranking, it will then arc and create a good current path. But then the contacts are even more burned. This will only get worse.

If it weren't a new starter, I would say to check the starter brushes and armature.
 
Success!! Thanks for the input guys.. Here is what I found. I stated my cables are 2 gauge.. Maybe thicker but look similar to my welding leads. What I found was the cable from the solenoid to the starter was mostly insulation. Looked like a heavy cable but actually was only the size of the average modern 12V battery cable. Replaced with a proper cable and all seems well now. Thanks again for the input. If I hadn`t removed the solenoid I could still be scratching my head. That is when I saw the strand thickness in the cable.
 
I'm really glad you found the problem. But I want you to understand why what you found fixed it. Now you know it was a bad cable if the cable had looked perfect on the outside, how would check it?

With 6 volts it requires twice the amperage to create the same power as 12 volts. The power output is measured in Watts. You've seen it printed on house light bulbs and appliances. It works the same on your car If you take 12 volts multiplied by 200 amps you will arrive at 2400 Watts. It's going to take 400 amps with a 6 volt system to deliver the same 2400 Watts of power. That is why the cables must be larger on a 6 volt system, they carry way more amperage even thought they don't crank as well as a 12 volt system. Why that is I don't know? Watts is the electrical measurement version of horsepower. Its how much work is getting done.

Now the automotive industry is talking about going to 48 volts. By pushing up the voltage it will not take as much amperage to perform the same amount of work. Amperage is the actual electrons that are flowing through the wires. Voltage is what's forcing them to flow. One Amp is a billion,billion electrons passing by a single point in one second. If less amperage is going to be flowing with 48 volts the wires can be even smaller which will save them money, weight and create more room to stuff even more electronics into the car

Your problem could have easily been found in just a few minutes with a digital volt meter and performing a voltage drop test . It will pin point any resistance in any connection, cable or your starter. There are some really good YouTube videos that will show you how to do this test. Its really easy and you feel like your an electrical genius once you try it out.

You could still have more resistance in your starting circuit besides that one cable. You can't see where electrons have the potential to move and where they are blocked from moving with your eyes. that's what scares people from working on electrical stuff. How can I fix what I can't see? The volt meter replaces your eyes, it can see what you cannot. If you point it at what you want it to see, it will tell you exactly where that problem is at. Everybody that is going to work on cars needs a digital voltmeter!!! It will pay for itself.

I'll give you an example of an electrical problem that drove a dealership crazy and almost resulted in them having to buy the car back under California's Lemon Law. A new car kept coming back in with intermittent starting problems. The mechnanics replaced everything but the battery cables and it still kept coming back with the same intermittent problem. Somebody finally tried a voltage drop test. I'm not talking about a resistance test. That will not work on a high amperage circuit with a large cable. Because the amperage your using from the meter to check for resistance is so small it can flow right through that large cable and never show you any resistance on your meter. But a little resistance is going to have a huge effect on 300 amps trying to flow through that same cable. The only way to check that cable is with a voltage drop test. What the mechanic found was when the factory crimped on the battery post end they did not strip the insulation off the cable. Sometimes there was just enough contact to start the car and other times there was not.

The way this test works is you set the volt meter to the 12V DC scale or whatever scale is the next highest voltage than you are testing. Put the positive lead on the battery post and the negative lead on the cable end. They are an inch a part but there is a connection point between the two leads. Disable the engine from starting. Now have someone crank the engine while you watching the meter. Lets say it reads zero. That's good, all the voltage went through the battery terminal connection and none of it through your meter. There is zero resistance there. Now move the leads over. Put the positive lead on the battery cable terminal end, not the battery The other lead is getting clipped on the opposite end of the battery cable. Now repeat the cranking test. Now the meter reads 3 volts. What just happened? That cable no matter how nice it looked cannot handle all of the 12 volts. There is resistance in it. Whatever voltage cannot get by the battery cable takes the side street which is the lead going to your voltmeter. The voltmeter reads the voltage pressure as it passes through the meter. Then the voltage continues on its way down that side street past the battery cable blockage down where it hops back on the cable at the opposite end. You can thinks of it as cars going down a road, water flowing through a pipe or what they really are which is billion and billions of little workers. That you can can control Then it becomes easy to understand.

If it doesn't make since. Go to those YouTube videos on Voltage drop testing, Your not going to take it all in the first time you watch them. Some of these videos are much better than others. I promise you if you master this one test it will inspire you to tackle electrical electrical problems with confidence. If you were here in person I could teach you in just a few minutes how to do a voltage drop test.
 
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