Hey Skibby,
Glad to hear that the dealership was able to find the original problem and it was just a simple forgotten battery cable. Sounds like they were even a bit embarrassed after you pointed this out to them. I'm sure not one to gloat though, made the same mistake myself which is how I was able to help you out!
First off, sounds like the bilge was not operational prior to the dealership working on the boat, but the fuel gauge not working is a new issue? lets just assume for now that the fuel gauge not working is simply coincidence and not related to anything the dealership did. Also, I assume you meant to say 'fuel gauge' in your last post not 'bilge gauge'?
If the bilge pump is blowing the fuse when you switch it on then the motor is likely ceased up or short circuited and just needs to be a replaced. This should be easy and cheap to accomplish. Had to do the same thing to the blower fan in my boat, motor ceased up, kept blowing fuses; replaced fan and have not had a problem since. You should be able to find a replacement bilge just about anywhere, its pretty standard equipment at any marina.
Fuel Gauge Issue:
1. How did you determine that the fuel gauge is not working? How much fuel is in the tank now and what are the symptoms?
2. Are all the other gauges working (tach, spedo, warning lights)?
3. Do all the gauges light up when you turn the boat lights on etc.? Does the fuel gauge light up when you turn on the boat lights? (even though the lights should be completely unrelated to the gauge not reading, I believe the gauges have a common ground for the lights and gauge function. Non operational gauge lights could point us to a bad ground for instance. Most likely unrelated but never hurts to cover all bases to get an overall picture of whats going on)
The reason I ask these questions is that we need to determine if the gauges (and specifically the fuel gauge) are getting power. I suspect the dealership was working around in the console fuse box when you had it in for the original problem and they could have dislodged some of the gauge cluster wires back there which could in turn cause the fuel gauge to not work. Need to determine if there is a problem with the gauge or the sending unit (fuel pump).
Check these preliminary things first before pulling the pump out of the tank, no sense in creating unnecessary and costly work. Electrical issues can be a real pain to diagnose, but you need to be diligent, thorough, and follow a logical process down to the root of the cause. I always like to start at the top and work my way down as systematic as possible. I am not an expert on diagnosing fuel gauge problems, so it may be helpful to open up the repair manual (downloadable from this site if you do not already have one) and review the diagnostic procedure they have for the fuel gauge which I am sure is in there somewhere.
If you can provide this additional information it will help us narrow down the exact cause. Good luck!
--Deven