Starter problem

GaryOR

GaryOR

Member
1978 Scout II, rebuilt over the past 4 years and just very recently became a driver. Intermittent starting problems, as if the battery is weak. Usually can be started with a jump.

Starter and battery replaced since onset of problem.

I think I have a battery drain, slow while sitting, quickly increased to the point of preventing the battery from having enough juice/current to turn over the motor when turning the key. Sometimes turns very slowly, sometimes not at all.

Battery has only 11.75 volts sitting last night. 10 hours later, measures 11.66 volts.

When turn key to run position, voltage drops to 11.4. When turn to starting position, voltage drops into the 6 range.

I think one of the wires in the ignition/starter system May be shorting to ground, but not sure where to look or how to isolate. Any suggestions?

Also, solenoid has r and s posts. What is the significance of the marks? Replacement starter was reconnected the same, assuming my son did it correctly.
 
Do you have a multi-meter. If so remove the battery ground terminal and with your mm in amp setting put it between the battery neg terminal and the ground cable. Do you get a reading with everything off. If so what is it?

You can try removing the fusees from each circuit to see if the draw on the battery stops.
 
I concur with the suspicion of a parasitic drain. Chappie has you on the right track. A parasitic drain is damn hard on batteries and alternators if left unchecked for long enough. The 'r' terminal is a resistor bypass feed for breaker points which provides full voltage to the coil only during starter cranking to aid in cold starts. Once the engine roars and the starter is released, the switched ignition feed to the coil keeps it running. The 's' terminal provides the switched impulse that throws the solenoid and engages the motor.
 
Ok. Interesting finding. I removed the ground cable from the battery and measured between the 2 for current. Got none.

While the ground cable was off of the battery, I measured voltage between the positive terminal and the disconnected ground cable. Got 0.09 volts that ticked down about 0.01 per 2 seconds.
 
Ok, charge the battery fully, then remove from charge and let sit for a few min and note the voltage. Recheck over a few days. If it drops below 12.5v perhaps there is a defect in your new battery.

The small voltage you measured May well be a clock radio or something small like that.
 
You might try using an incandescent test probe instead. The exact amount of drain isn't important. What matters is if the bulb stays lit, even dimly, or pulses. If it goes dark right away, then there's no drain. I once traced a dead short in a subaru waggy caused by a coffee flavored drink that had spilled down into the radio unbeknownst to me. The radio was still working, but it was also constantly draining the battery to the point of eventual ruin. It took me awhile to track it down. Wasn't my car, so I couldn't work on it any time I wanted. Anyway, the simple test bulb was all I needed to confirm that a drain existed. Then it was a matter of tracking the source.
 
Alternator replaced. Wrapped a couple of wires and tightened some connections. No drain found but now the battery is holding a charge.

This problem fixed. Now on to the next...
 
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