Sluggish starter

[Jim Yergin]

With the return of warmer weather I am back out in the garage trying to start my '41 Plymouth. I had it running back in December but took the carb off to send to George Asche to check. After reinstalling it I couldn't get the engine to start. I discoverd a short in the armored ignition cable and was able to repair it. Then the weather got too cold for me to work on the car.

Now I am looking for some insight as to what the problem may be with a sluggish starter. The starter has been rebuilt, I installed new 00-2 battery cables and I have a new battery (car is still 6 volt). However the starter is very sluggish and doesn't seem to be turning over fast enough to start the car. The battery loses its power after only a short time of running the starter. I checked for resistance between the body of the starter and the end of the ground battery cable and there was none so it appears I have a good ground connection to the starter. I have also cleaned and reattached the cable ends from the negative battery terminal to the starter.

Any ideas what the problem is and how to fix it?

Thanks.

Jim Yergin

[Merle Coggins]

Bad or weak battery perhaps? If one cell is bad in the battery, it may show 6 volts surface charge, but when it is under load it could be dropping off to 4 volts or lower. Connect a volt meter to the battery and measure the voltage before and during cranking. This should be similar to using a battery load tester and will give you a good idea of the state of your battery.

Merle

[Norm's Coupe]

I agree with Merle. Try charging the battery up. If it doesn't hold the charge then, the battery is probably bad even though you just put it in a few months ago.

If you let a battery sit for several months without charging or using it, the plates could build up a crust on them. That will kill that cell or several cells in the battery. You can usually charge them up that way but they won't hold a charge after that crust builds up. Then you have to replace the battery.

During the winter months you should either start the car once a month and let it run, or put the charger on it once a month to keep the battery in good shape. Or, put a trickle charger on during that time.

[Jim Yergin]

Thanks Merle and Norm. I will do the load test. I have had the battery on a battery tender trickle charger from the time I installed it but I guess anything is possible.

Jim Yergin

[Merle Coggins]

Even if it's a new battery doesn't mean much to me. A co-worker here is working on a Willys pickup for a friend. He bought a new 6 volt battery for it, but it would crank very slow and would only crank a few times before it wouldn't crank any more. He would connect his battery charger for several hours and would get the same reaction again. I suggested new cables, so he made up new battery cables with 00 cable. No change. He tested the battery with a load tester and it would drop to under 4 volts under load. He took it back to the battery store where he bought it. They tested it and said it just needed to be charged, even though he had it on a charger before he took it in. They wouldn't take his word about that (just assume the customer is to stupid to understand batteries?) They put it on a charger over night only to determine that the battery was indeed bad. They get him another new battery. He hasn't tried this one yet, but it does test out better. This one will at least hold 6.3 volts on the bench. The other one wouldn't.

Merle

[Lou Earle]

These 6 volt batteries are slow to charge- a completely dead one will take at least 12 hours at 6 amps. Also If you have one put a "fully automatic" 2 amp

charger on it after a 6 amp charge to really build it up. Most of the time we just charge the surface so to speak. The battery guy taught me this- he charged mine that way and man what grinding power now.

One of my best improvements is a 25 buck set of welding lead battery cables he made for me - You will think your cranking with 8 volt battery

Lou

[Jim Yergin]

Lou,

I will give your charging tip a try. I have brand new 00-2 battery cables on the car.

Thanks.

Jim Yergin

[Jim Yergin]

Merle,

I tested the battery as you suggested. At rest the volt meter showed 6.6 volts. While cranking it showed 5.1 volts. What does that indicate about the condition of the battery? The battery is a low priced one from Tractor Supply. Is it possible that it does not have sufficient cranking amps? I couldn't find any specifications regarding cranking amps on the battery. I guess I would have to check that out at the store. What would be a good number?

Thanks.

Jim Yergin

[Plymouthy Adams]

As I understand and read this chart, the P15 starter will draw 68 amps and turn 4000 rpm at free running speed and pull voltage down to 5.5 volts

The only other real method is to check the stall torque..this is very involved as you will need the correct resistor, ammeter, torque arm and spring scale...etc etc.

[MBF]

I believe that a fully charged 6 volt battery should show about 7-7.5 volts on a volt meter. Starting out with 6.6v sounds like you've got a week cell or the battery is not fully charged. How long does it take to drop to 5.1 volts? I think a good rule of thumb is to have 1 cca per inch of cubic displacement of the engine. I've never had any luck with Tractor Supply or NAPA 6 volt batteries. Any wet cell battery starts to deteriorate as soon as the electrolyte is added to the cells. Another problem that could be causing the problem is whether or not the rebuilder seated the new brushes in the starter. Sometimes if these aren't seated during rebuild, it will take them awhile to seat themselved during use-in the meantime you've only got partial contact of the brush(es) on the comm.

I converted my '36 Plymouth, and 52 Dodge to 12v. I got tired of replacing the 6 volt battery every year just after they went out of warranty. I also tried the 8 volt route for the Plymouth. I know that the 12v isn't original, but I like the reliability of the alternator. Just my 2 cents.

[Merle Coggins]

How long did you crank it? If it held that 5.1 volts for at least 15 seconds I'd say the battery is OK. If it continues to drop over that time it may be getting weak, or just need a good charge. If it can hold above 5 volts for an extended period of time (no more than 30 sec or you'll overheat your starter) that would indicate that your battery is strong, but if it still cranks slow then your starter circuit is drawing too many amps for some reason.

[Normspeed]

Jim, it's possible for a solenoid to still be connecting but making a high resistance connection internally. You might put the car in neutral and block the wheels, key off, and do a momentary jumper across the two large solenoid lugs. This bypasses the solenoid out of the starter circuit. You need a heavy bypass like a good jumper cable. It will spark.

Also after you crank it for a while, have you tried feeling all the cables and components to see if any are real hot?

Only other thing you might check is dirt or oil buildup on the armature. Might need to pull the starter out or if you're lucky you might be able to pop off the steel band to inspect it in the car. If it's real dirty you could shoot some electrical cleaner in there then try it.

[Rodney Bullock]

Hey Jim, It sounds like you have a wire crossed, it may be at the back of your ignition connection at the ignition cable. also check your starter relay, if it is not grounded to the fire wall the starter will turn slow. The final thing to check is if you have ground straps in the right places. I have one going from the fire wall to the motor. The frame to the body. Good luck and great to hear from you!

[Rodney Bullock]

Jim, The 6 volt battery comes in different groups. I think our 40-41 is a group 2 battery. This guy is the leading battery guy in our area.

Harrell Batteries

7424-a Old Alex ferry road

clinton Maryland

301 868-1170

talk to Dennis Scholl

He can tell you anything about the battery and he can slow trickle charge your battery.

[Jim Yergin]

Thanks everyone for the tips. My car is '41 P12 with a mechanical foot starter. No solenoid or relay. I am charging the battery per Lou's tip and will see what that does. I will also redo the load test and time how long it takes to drop the voltage as well as check for any heat on the cables.

The battery I have is a group 1 battery. Is that less powerful than a group 2?

Thanks.

Jim Yergin

[Norm's Coupe]

Jim,

I've always used a group one. The battery manufacturer that I go to looked it up and said it is the right one.

[Young Ed]

Jim I've heard of people having a dirty contact in the switch that the foot pedal pushes.

[james curl]

The foot starter on my 55 Chevrolet Pick Up also has a foot operated starter. I have to replace the foot operated solenoid because the copper bar that contacts the battery terminal burns and no longer makes good contact unless you really stomp on the foot pedal. If you do not press down hard enough to get a good contact it will burn the copper jumper bar. My wife is just 5.0" tall and has short legs and when she drove the pick up all of the time I was constantly replacing the foot solenoid because she could barely toe the foot starter..