420 C Crawler

[Pardner]

I have a 420C (year unknown) crawler with a new rebuilt starter; two fully charged batteries (parallel - 6.9 volts each). When I hit the starter it will only turn over 5 or 6 times and drains the new batteries and then won't run again. Has this happened to anybody else? Were you able to fix the problem?

[Lavoy]

A few possibilities, bad starter, bad wires, bad ground, bad switch, are the first things I would look towards. I know you said the starter is rebuilt, but I would bench test it to double check.
Lavoy

[Lu47Dan]

A few possibilities, bad starter, bad wires, bad ground, bad switch, are the first things I would look towards. I know you said the starter is rebuilt, but I would bench test it to double check.
Lavoy

+1
Clean the battery (+) ground where it bolts to the center frame, then pull the starter out and clean the mating faces of the center frame and starter. I worked on a neighbors tractor that would do that but you could pull start it. I had the starter tested, the battery tested and checked the resistance of the battery cables. All tested out good.
The tractor had been repainted just before this problem reared its head. I cleaned the paint off the starter mounting pad and the starters mounting flange and the problem went away and has stayed away.
Dan.

[Gil]

Are these "automotive" style 6 volt batteries you are talking about? Do you have a load tester to test that they really have a current capacity when charged or are you just depending on the fact that you had them on a charger? When you say they are drained, can you test that, or are you depending on the fact that the starter will not turn anymore? If two new parallel (are they hooked up negative to negative and positive to positive?) automotive batteries drain in the time it takes to turn the engine over a half dozen times, you should see smoke coming from somewhere, and the wires should be very hot.

If a bad ground is the problem, that will cause your starter problems, but it should not be draining your two batteries like that. The starter is wired directly to the batteries. If you do not turn on the ignition switch but just pull the starter lever, the only things drawing current are the starter and the connection contacts in the starter switch.

You should disconnect the batteries when you charge them; and disconnect them from each other. If there is a direct shorted starter cable you will see a spark when you reconnect either battery, even with the ignition switch off and the starter lever not pulled. If you do have a direct short and you do not disconnect the batteries when you charge them, it could be draining your batteries even as you charge them. Then when you try the starter, it would only turn a few times because there is very little charge there.

I would buy a cheap twenty dollar load tester (you want to have one around anyway) and verify that the battery (I would not complicate thing with your parallel arrangement until you have this figured out) holds a strong charge. If the battery is good, check the connections, including the trick about the ground that Dan mentioned. Run the starter and then use the load tester to see if the battery is in fact going from a strong charge to a discharge. You could have a bad or incorrect battery, your mechanical switch could be shorting out (you can easily take it apart to see), or your rebuilt starter needs to become a rebuilt-rebuilt starter.

Note: you can remove the spark plugs and allow the starter to turn the engine easier and to verify that you do not have some sort of problem with your engine that is keeping it from turning freely.

[Tigerhaze]

I would second the load tester. Oftentimes my batteries will appear to be normal on a charger and even light up a test light but once I use the load tester it is apparent the batteries are junk.

[OneWelder]

If I am reading you correctly you are saying two new battery's are being drained of power almost immediately - I would look for something getting hot - real hot ! - carefully feel cables and connections for heat , check starter for heat - This is just a quick check so is not infallible , but if no heat is found I would look hard at the batt. and then get into serious testing
If the energy is in the batt. it has to be going some where - either heat or turning starter

[Stan Disbrow]

Hi,

If the batteries have sulfated plates, then they will appear to fully charge yet only deliver for a few seconds before going dead - as far as suppliing current to a starter goes. The sulfate coating on the plates greatly inhibits the ability to produce large amounts of current for any length of time....

Hook a digital voltmeter onto the battery terminals and then crank. If you see the voltage go essentially away, yet nothing is getting hot and/or smoking, then you will have your answer.

Later!

Stan