"Roadster starting issues after being driven a few mile

[PROUD ROADSTER OWNER]

Hi ! I have a problem with my 1969 SPL311 1600 Roadster that is driving me crazy and any help would be much appreciated ! Here is the status of what I've done to this point.
Replaced the starter with a NAPA rebuilt starter and wrapped it with the insulation to keep the exhaust heat from cooking the starter. New battery with more than adequate cranking power. New battery cables and posts. Timing set at 16 degrees BTC.
Started car after doing all of these things and let run for 25 minutes then shut it off and it cranked up like its supposed to. Feeling confident that it was fixed drove the car 25 miles one way last Sunday to a car show and it would very turn over when I tried to restart it and needless to say it wouldn't turn over fast enought to start. Let the car set for a little while and it will start right up. I do remember one thing of significance that happened on the way to the car show I had to use my wipers and they were very slow but don't know if this is of importance . Another thing of importance is the motor only has approx. 300 miles on a overhaul.
HELP !!! THANKS DON !

[spyder]

Have you tested the charging system to see if it is up to par?

[douglee3rl311]

You need to test the charging system, I had the same thing happen to my 2000 and after replacing the resistor with a WELLS CR105 resistor it took care of it.

[dbrick]

My guess, either not enough voltage, or bad connection on positive or ground. I am assuming you have a good ground from starter to frame and frame to battery etc. I always use very oversize cables, just because it can't hurt.

Get a voltmeter of any kind. Check voltage before cranking, while cranking with no problrm and while cranking with the problem and compare. Make sure alt is charging the battery fully, around 13.2 volts engine off. Wipers could be voltage or ground problem.

To eliminate timing, pull the coil wire and crank while it is having the problem, if it is much faster with no spark, look to the ignition timing and vacuum advance or point plate sticking.

[PROUD ROADSTER OWNER]

Thanks for all your input. I don't have a ground from the battery to the frame but will add one and check out the other grounds. The ballast resister is old so I have purchased another one. The battery is new and checks out with volt meter. I will restart car today and check it out if it won't restart once warmed up. I will LYK if successful !! THANKS AGAIN DON !!!