Yup, guys, pretty sure the main problem was the positive terminal. The wires were encapsulated in lead from the factory, had no breaks at all–but were corroded internally.
Since nothing could get at it inside the lead, I’m guessing the cause of failure was excessive flux used in the manufacture, left for 21 years to do its magic.
Any event, a new terminal did wonders.
Double check to make sure the battery isn’t leaking battery acid somewhere. Even a small leak, the acid can decant down a cable that touches the leak, get inside the wire’s insulation, and eat the metal. I had that happen on my Corolla, debugging a non-functioning radiator fan. There was no visible acid leak but I discovered battery acid had eaten away a wire splice in the wire powering the radiator fan. The splice was inside a big bundle of wires. When I removed the outer insulation for the bundle and separated the individual wires, I discovered they were all coated with battery acid. The acid didn’t hurt anything until it eventually reached the wire splice deep inside the bundle, which is promptly ate in half. When I removed the battery from the car and cleaned it off, the next day I noticed a tiny crack in the case and a small leak. Right where a wire going into the bundle touched the battery.
So when diagnosing problems with the starting circuit, common techniques like test lights aren’t of much use. You need a way to measure electrical resistance accurately down to a few thousandths of an ohm. 1/1000 of an ohm will produce a voltage drop of 1/10 of a volt at 100 amps.
No you really don’t need to measure resistance at all. A FAR better method is to measure VOLTAGE. Had the voltage been measured across the positive cable I’m fairly certain it would have told the entire story. A good cable, when measured even with the starter motor operating, will measure less than one volt from end to end. This cable clearly measure much more than that and was where all the voltage was lost.
It’s called measuring voltage drop
is the starter solenoid still on the side fire wall in a 94?
If there was any flux on the wire it wouldn’t matter, flux doesn’t corrode wires. Somehow there was a compromise in the sealed wire and battery acid did its’ thing. Rack up another service job due to lack of battery connection maintenance.
with my old ford every thing runs thru the starter solenoid and intermittent solenoid failure and solenoid terminal corrosion can present itself in the same way as battery terminal corrosion…
On the older Fords at least, the accessory power did indeed tie off from the starter solenoid but it was the same point that the main positive battery lead tied to. The only power that ran through the solenoid contacts was for the starter motor. Even if the starter solenoid totally failed it wouldn’t effect the accessory power.
Yes, as @JayWB mentions above, the practical method to diagnose resistance problems in the starting circuit is to measure voltage drop during attempted cranking. Measuring the actual resistance of the wires and connections to 1/1000 of an ohm is too difficult and isn’t necessary. One quick way to do this is to simply measure the voltage right at the starter motor terminal, between it and the starter case. During attempted cranking.
Say it measures 10.0 volts between the starter motor terminal (for the thick wire, the battery feed), and the starter case, during attempted cranking. And the battery measures 12.5 volts with no load; i.e. with the key out of the ignition. That means there’s a total of 12.5-10.0 = 2.5 volts of voltage drop in the starter motor circuit. Part is due to resistance in the wires, part due to resistance in the connections, part is due to resistance inside the battery. It’s not possible to say where all that 2.5 volts is coming from doing this test, but just that’s the total. 2.5 volts of drop is ok, but nearing the limit at which a working starter motor won’t be able to crank the engine.
“Measuring the actual resistance of the wires and connections to 1/1000 of an ohm is too difficult and isn’t necessary.”
You could have a single strand of wire, the thickness of a human hair, and the resistance will test perfect end to end, perhaps 0.2 ohms
It will certainly not be sufficient to use as a battery and/or starter cable
I seem to recall suggesting PRECISELY THIS PART… But it was on a different post… LOL Same vehicle tho Frown 