1948 A Starting Issue

[DougJD48A]

I am having trouble getting my John Deere 1948 A to start. The starter is turning the engine over very, very, slowly for a few minutes before the battery dies. I might depress the starter pedal for about 15-20 seconds per attempt. I replaced the battery a few years ago (12 volt battery) and it started but even then the starter turned over very slowly like it was not getting enough current. I have the petcocks open since it will barely turn over if they are closed. I have been keeping the battery inside and charge it before I try to start the tractor. The battery cables are getting very hot. Fuel is coming out of the petcocks and there is spark. This was my grandfather's then my uncle's tractor and they are no longer living so I don't know the last time any wiring was changed out. The system is 12 volt and the tractor has a distributor cap. I am guessing that my first step is to replace the battery positive ground cable to the frame and the negative cable to the starter? Most of the other visible wiring on the tractor has cracks in the insulation, so I think it has never been replaced. Should I look to replace all the wiring? Are there kits available for this? Sorry for the naive questions, but I just don't know enough mechanically about these tractors. This tractor is very important to me and I am really trying to keep this great tractor running. Everyone has been so helpful on this forum in the past and I do appreciate everyone's help and insight.

I would greatly appreciate any help,

Doug

 

[old]

Battery cables getting hot say starter is going out and drawing to many amps or the battery cable them self's are going bad either or both and the more times the cable get hot the more likely they will need replaced also due to having to high a n map draw. Sounds like it it time to pull the starter off and have it checked

 

[Dan in Ohio]

Doug,

Replace both battery cables first, chances are the starter is fine but if the cables are original they NEED replaced. You can get cables that are less expensive than John Deere stocks. The negative going to the starter needs to be 66 inches long and the larger the gauge the better. I just bought cables at TSC for $36 (66 inch) negative cable. The positive cables are relatively inexpensive if grounded as original.

 

[DougJD48A]

Thanks very much for the helpful comments.

 

[John T]

If actually needed ? or in doubt, it shouldn't hurt and may help cranking performance if you replace the POS with a good heavy say 1 or 0 Gauge copper ground cable and its good if its at a bolt on or near the starter motor versus any thin wimpy rusty sheet metal like the seat frame or battery box. If needed replace the starter cable also.

Of course you need a good heavy duty full charged high CCA battery. If in doubt have a shop load test it to be sure.

I have seen many starter switches or the copper starter post under the switch go bad or get burned pitted and carboned causing poor cranking. They are not too expensive so insure its good and replace if needed.

Be sure each and every starter and ground and battery post connection is clean bright n shiny.

If battery and cables and connections and grounds and starter switch are allllllllllllll good but she draws excess current and cables get hot and she cranks slow its time to suspect the starter motor itself is bad, have a shop test it.

John T

 

[DougJD48A]

I will replace cables first and check all those connections. This forum is really helpful and I appreciate all your knowledge.

 

[Rich'sToys]

Where is the other end of the ground cable connected? Many of those were just bolted to that tin battery box. If so, run it down to the main frame somewhere. On my 50 I found a hole down by the rockshaft and bolted it there.

 

[Mark-Ia]

Replace them with a large cable,not the small automotive style.

 

[Mike M]

Would not surprise me if the bushings were bad in the starter and it was dragging the armature. If caught in time hopefully it won't be burnt up inside.

 

[DougJD48A]

I will check all these things out. The positive from the battery is grounded to the outside of the battery box near the seat platform, so I will definitely look to move that ground to a bolt closer to the starter itself.

Thanks for all the help, Doug

 

[NoDakInMN]

Went through this exact thing with '50 B I got. I knew the starter was good because I pulled the plugs so the engine couldn't fire and left them connected to the mag to protect it, then hooked the starter to a battery charger and she spun it over fine. Replaced the cable with a heavy one and that solved it. What I found was that corrosion worked its way up in the cable, which raised the resistance of the cable considerably. High resistance results in a volt drop which then spins the starter slowly.