Electrical issue on my motor home?

I have a 1996 Georgie boy, diesel pusher motor home that I'm having an electrical issue with, the speedometer needle doesn't show the correct speed when accelerating, and the turn signal does not work all the time.
Can you please give me any advice on how to test where I could find where this problem is coming from?

Thank you,
JN

A maintenance manual with a wiring diagram or a schematic is an absolute necessity for tracing electrical problems in a mobile home. You'll need an electrical meter that reads D.C. also.

If the turn signals are doing the same thing on the front and back, that would indicate the problem is with the switch or the capacitor used to time the blinks. If it is only happening with one light, relpace the bulb and look for a loose connection between there and the switch. Intermitten problems are often hard to locate.

The speedometer may be a mechanical problem, depending on how it's made. Your description sounds like something might be hanging when the torque increases. It all depends on how it's made.

With a mobile home, the manuals are often as valuable as the home itself. because so much of the wiring gets buried in the walls and floor before the unit is built over it.