On my 66, I'm having a strange problem. I searched the forum a bit but couldn't find this exact issue. My battery seems to charge intermittently. The car will start right up cold after I charge the battery. After it starts, I'll let it run for a bit then shut it down. I'll let it sit for an hour, then re-start it. About 75% of the time, it starts right up and the other 25% it can't muster the power.

It's a brand new maintenance free tar top repro. The wiring is all brand new. I'm also using a combination of rebuilt and original electrical pieces. Voltage regulator and horn relay are nice originals that were tested and work fine. The alternator is rebuilt.

I'm having a couple of other electrical issues that I haven't really checked into yet. Dome light stays on all the time so I took the bulb out. Also, the front parking lights are not working. Everything else is working fine.

Any ideas? :confused: Do I have a short somehwere?

Thanks in advance.

I have one of thos maint free repop batteries and it starts my 396 with approx 9:8 comp just fine.

1st thing would be to fully charge it then take to local autozone or car shop to have it loaded tested to ensure its not defective. Its fairly low cranking am output battery thats marginal at best for hot bbc starts so the rest ofs the starting system must be in god cond and properly setup ofyou will have hotstart problems. Thar repop battery has like 500cca/650ca and i like to see 700cca/850cca for best hot starts with bbc so you can see the repop battery is weak. Yes i run the repope for the look but i know wheh it gets a few yrs old it will likely not start my bbc hot well either but thats the price we pay for the original look with this maint free batery vs the older acid flooded design repopbatteries that have higher cranking power but with the acid issues that go along with it.

Check to see that when you start the motor with a fully charged battery that there is a min of 13.5 volts at battery at idle and 14-214.5 volts at battery at 2500 rpms to ensure it's charging.

If you dont have those volatges at the battery then the rblt alt or volt reg is likely the culprit or poss wiring issue too.

But your problem may be a weak or non hi trq start thats the issue along with maybe its missing the starter heat shiled so starter is heat soaked and cant start the motor when hot.

If thats the case the damage is already done to the starter since its having trouble starting hot so have the starter rebuilt if its a hi trk starter. If its not a hi trk starter simply buy a new one from summit/bround up/yr1 etc and also install a starter heat shield too.

scott

Thanks Scott. At this point, I'm thinking there must be something draining the battery faster than it's charging. I don't think I have the heat issue you described....at least not yet. I haven't run the motor for more than an hour all together since it was assembled. I'm gonna do the thing with the test light while I pull fuses to see if I can isolate the issue.

Thanks!

Where are you going to place the test light? Between a battery post and the cable? Don't forget to pull the wires to alt as it's a possible source of drain on the battery that you won't see by pulling fuses.