Wiring question

[toonin22]

Now I have an older pontoon boat and none of the gauges work. Could it be a bad relay? I just am not sure where to start. Should i use a DMM or test light? Could I do a voltage drop test..could it be corrossion? Do the gauges require +12? Any help would be great.

 

[mr 88]

Re: Wiring question

Does it have fuses? Take a test light or DMM and see if you have power on the fuse block side coming from the battery,One side of the block should be "hot" the other side as well, as long as the fuse is good or does not have a little corrision between it and the metal tongs.12+- volts is what they require,a battery will flucuate up to 13.2 or so,not critical in this case.So start with end of lead from battery and go on to the next connection.Probably fuse / crusty connection or bad ground wire.

 

[Silvertip]

Re: Wiring question

There are no relays involved with the gauges and checking power at the fuse panel or checking for blown fuses is a waste of time since that's not where the gauges get their power. The "A" (accessory) terminal on the ignition switch is where power for the gauges comes from via the engine harness. If all gauges are inoperative then there is a loss of +12 volts and/or ground. From the "A" terminal on the switch, power is fed to the "I" (ignition) terminal on the first gauge in the string. It then passes to the next gauge, then the next. Same for the ground connection. Therefore, since none of them work, it is obvious the +12 volts and ground feed is missing. The ignition needs to be ON when looking for the trouble. There is a generic wiring diagram at the very top of this page in the "Stickies".