Radio

[stock333]

Hooking up new radio I get 13 volts from yellow wire, 13 volts from red wire when I check in the front part or back part of the harness. When I plug the harness into the radio it does not power up and if now I check the harness that is connected to the back of the radio I only get 4 volts. If I connect the red and yellow together and attach to battery and ground to negative battery the radio will go on so radio is fine. Any idea why drop in volts, When harness s plugged in radio from helm wires

[mmwjr]

Can you post a few pictures?

[2004_3300_SCR]

Sounds like a marginal connection that is dropping voltage when load is drawn. Had this happen to my depth finder and MFS panel circuit. Culprit was a dirty connection at the fuse panel. I cleaned it and changed the push on connector. Eventually I swapped out all the fuse panels under the helm, using blue sea systems panels that have screw on terminals instead of push on. Try inspecting and cleaning the connection at the fuse panel for the wire that is dropping out. You can protect the cleaned terminal with a coating of dielectric grease.

[stock333]

JUst curious, when I turn the battery on should I have power in the yellow and red connection without turning the key to accessory or completely on to start the boat.

Thanks

[2004_3300_SCR]

Depends on the model boat you have. The 3300 is live when the battery is on, not switched by the ignition. Smaller runabouts in the 20 foot range - I've had some that are switched to an accessory position in the ignition switch, like a car, and others where there is power when the battery is switched on, like the 3300.

[stock333]

It's a 25 Sr bow rider. Thought that when battery is on only 1 wire has 13 volts and when ignition is turned to accessories then both wires have 13 volts I have 13 volts on both wires with just the battery on.

[mmwjr]

Typically the red power wire is switched on/off with the battery switch while the other wire is always powered to maintain memory for settings.