Well sense you asked that question I have to say.
In almost every town there is an auto electrical shop that has been in busness for 20-30 years and every shop in town sends there electrical problems to them.
This shop is usualy very honest and you should seek that shop and ask them for a bit of help.

Don't be discuraged if they cant give you an exact estament because they can't.
Electrical problems have to be diagnosed with a process of elimanation and (experenced hunch) method.

They will prob. say well just spend an hour and then let you know were we are at. If that first hr. doesn't give them enough time to diag. and fix it. (it usually does)
then you can go from there.