Wirring issues with Yamaha 703 Control

[david123]

Hi there, I have wiring questions for a 703 Control connected to analogue gauges (the outboard is a Yamaha Saltwater 130). The Red (from the Black, yellow, red, green harness) is not connected. Is it normal?
The oil, temperature and fuel gauges are not moving when the key is on and the engine on run. they all received power (~12V), but the fuel gauges with only 7.5V: I really don't understand why.
Will the oil and temperature sound alarms (buzz in the control) still work if the gauges are not working (I guess they are independent, but am not sure).
Thanks much for your help.

[boscoe99]

Hello.

Red is battery power. Available if needed. Oft times not needed. Normal to not be used.

Key on power (~ 12 volts) is provided to the gauges via a yellow wire when the key is in the on or the start position. A wiring/connection issue can result in a loss of voltage to one or more of the gauges.

The warning horn in the control box should sound whether or not gauges are in use. They are completely independent of one another. Pull the kill switch lanyard and crank the motor. The warning horn should sound.

[david123]

Thanks a lot. Really appreciate your help