Tiger cub solenoid?

35v AC / 2 = 17.5V DC.
Allow abut 10% for losses and you get 15V .
SO Yes there is a problem with the rectifier.
Usually a bad ground connection through the base.

Thanks again for your reply's . I removed the regulator and wire brushed the base, checked the leads and reinstalled . I got a reading at the battery of 13.90 volts. That is better than the 13.3 I was getting. To make sure I put a ground wire on the base but that didn't change the output. I am checking this with a new battery installed ,would that make any difference to the output. I did order a regulator , won't be delivered till next week.