Lower helm blower switch works, upper helm switch doesn't. Ideas?

[boatingbob]

I just bought a 1994 Carver 390 CPMY (gas) and love it. I'm learning how to do my own work. The lower helm station blower switch works fine, but the upper helm blower switch does not. The green indicator light does come on at the upper helm switch when the lower is used to turn the blower on.

Any ideas on how to troubleshoot/fix? Thanks in advance!

[Viper]

With a volt meter, check to see if there is 12 volts on the source side of the switch. If there isn't, you need to work your way back from the switch to the power source such as the electrical panel checking all connections and plugs along the way. You likely have plugs under the upper helm, they tend to corrode. If there is 12 volts, turn the switch on and check for 12 volts on the load side of the switch. If you don't get 12 volts there, replace the switch. If you do get 12 volts, the problem lies after the switch. Could be wiring or again the plugs. Or, if the upper and lower helm switches are the same, remove the lower and hook it up to the upper helm and test. If it works up there, replace the upper switch. Keep track of exactly which wires go to each contact on the switches. Keep us posted.

[Ramsport47]

First thing to do is gain access to the back of the switch to make sure it is still hooked up (behind the backrest of the fwd seat). Sometimes, wires will disconnect themselves if someone has run other wires over top of them. If the wires are attached, then start the testing process.