99 gt235 won't start, just clicks

99gt235 · Apr 17, 2016

I have checked the voltage of the battery w/o the key on (12.4 volts), w/o key on, but charger on (14.6 volts), w/ key on (9.2-9.8 volts), running (after being jumped) (14.6 volts) and when trying to start w/ charger on (3-4 volts). As soon as I turn the key back off the voltage spikes back up. I've taken all of the same measurements on the starter (positive lead on the solenoid's positive, ground on the battery ground). The only other thing I can think is that the starter is not getting a good ground since I have not cleaned that yet. I took the starter apart and cleaned it up (it was dirty), but I thought that cleaning it up would at least help confirm it was the problem and I would get a new one. The battery terminals are clean. All of the wires look fine (almost new), but it is possible something is broken inside of the insulation. Crossing the positive and switch terminals on the starter don't make a difference, so I think the switch wire is fine. Since I measure the same voltage at the starter I think the positive cable is fine. I have checked ground connections and the wire, which all look good. I will have to pull the connections and try cleaning them. I just don't understand how a ground could be bad, but jumping it would make it start. When I had a bad ground on my truck it wouldn't start no matter what. I appreciate the ideas. Keep them coming and I will try them before I just start throwing parts at it. Thanks!

Kish318420 · Apr 17, 2016

Weak battery won't hold load voltage when cranking. Pull battery take to local auto supply and test it. Once you have it starting good on what will be a new battery, check the charging circuit of the tractor not the stand alone battery charger. If the charging circuit is not working on the tractor all your are doing it doing a deep discharge and recharge of a light to medium battery that is not made to function that way.

bruceatlam · Apr 17, 2016

You cited 14.6 volts at the battery while running. That would, at least on the surface, confirm that your charging circuit is working OK. I do agree that you need to polish up all the battery connections and look closely at your cables for any signs that the cables are broken under the plastic covering on the cables --- look carefully at the ends.

Richard001 · Apr 19, 2016

Sounds like you have a bad battery. If it has cell caps, have you checked the water level?

Some info on battery's:

A battery's condition can be monitored by checking the electrolyte's specific gravity with an inexpensive D-I-Y battery hydrometer to determine the percentage of sulfuric acid it contains.

A fully charged cell at 80 degrees F would show a specific gravity of 1.265. If all six cells are fully charged, an accurate digital voltmeter reading of battery voltage would show 12.68 volts.

Specific gravity for a 50 percent discharged cell would drop to 1.19 and battery voltage would fall to 12.24.

When specific gravity reaches 1.12, the cell is fully discharged and battery voltage falls to 11.89 volts, assuming the specific gravity is the same in all six cells.

Because specific gravity is affected by temperature, subtract .004 per 10 degree drop below 80 degrees F.

Another thing you can check is to connect your voltmeter between the battery ground terminal and the engine block. Watch the volt meter when you attempt to crank the engine. You should see less than 1 volt. If not, you have a bad connection between the battery ground and the engine.

Richard