Battery Cable

[Buzzfagan]

Confused!!! So I am bench testing my motor with a spare bell housing and a battery cable and ground to the housing and it is starting and running fine.

Tunning it in and then suddenly can't get it to start anymore after shutting it down. I am using a cheap Harbor Freight push button "starter" button hooked up to the starter and battery. Worked for about 5 starts and then no response when I push the start button again. Also, have a "dummy" oil pressure light hooked up and it will not even light up now before I start it like it did the first few times.

So I look at every connection and all seems fine and still nothing.

Finally hook it up with some jumper cables (without the HF push button and bypassing the battery cable) Iike in a diagram I found online and the dummy oil pressure light turns on before it starts and then it starts again and the oil pressure light turns off when it is running (BTW???, is this how the oil pressure "dummy" light should work correctly; be on with power to it and then turn off when engine is running????).

So, I figure out well maybe just maybe it is somehow a bad battery cable, even though I can't imagine how a brand new battery cable could go bad.

Well I bought a brand new battery cable and hooked it up the exact same way as the original with the HF start button, dummy oil pressure light and the new battery cable and all seems to be working fine for about the first 2-3 starts and then the exact same thing happens; no response and no dummy oils pressure light on again.

And then I hook it up again with the jumper cables and it starts fine again and the dummy like pressure light works fine again.

What is going on?? Any ideas??

Also, is that how the "dummy" pressure light should work?

[Ken]

Alternator or generator?
A generator can loose it's polarity and stop charging. Either or they both require an exciter light. Oil pressure light not required.

[Buzzfagan]

Aternator

[johber41]

sounds like you might be having trouble with the coil. check your connections there, or maybe swap it and see what happens. It sounds like the coil is failing to energize after you use it a few times.