Dave with the cheese is right
the electrical part of your car is not difficult to understand,if you take a little time to learn the basics, electronics is somewhat more difficult. But you can save yourself thousands and avoid said tradesmen by taking the same approach with your electrical system as your mechanical system.A good approach is to look at every wire as if it were a hose with electrons running down it, & switches are taps.
(M61A1 CUPID- STUNTS, Sun 30 May 2010, 8:13, Reply)