Anyone know where to get a battery charger rebuilt/fixed? I have no idea what type of shop would do this work. Maybe have to send back to mfgr? (Guest)

You might try a alternator/starter rebuild shop?
Or West Marine has them starting at 299.99

Me too! I have a Guest 2615 which no longer works. I called Guest and they no longer make that model, and won't fix it either. They are trying to sell me an equivelent model for around $300.00. I would think it could be fixed.

When a battery charger dies , it's usually just a bad diode.
These can usually be checked with and ohm meter. Placing the leads of the meter across the diode... should be almost 0 resistance in one direction and almost infinite in the other direction. If it's open both ways , it's bad. Most electronic supplies should be able to sell you a replacement

Mopower is right on. Usually it is the simple things, poor connections, broken strains in insulted wire, diodes, switches, etc.

RadioShack has some parts and www.allelectronics.com has big selection, cheap. Be careful about diodes. They must have the right current minimum rating for the power ones. If they are zieners then the voltage is critical. If repair is beyond your talents try a local TV repair shop.

Thanks for the responses guys. I have a local shop that is a combination Radio Shack/TV repair shop. I'll give them a try.