PaulRainbow
Well-known member
Hi. Thanks for all the feedback. In response to a question the alternator is attached to a ECS163 quick charge separator.
Disconnect the fan and heck the engine battery voltage, with the engine running.
If the battery voltage is stable, it must be the fan or the fan wiring. Connect the fan directly to the battery to determine which it is.
If the voltage still fluctuates, swap the domestic battery and engine battery connections on the ECS163 and again measure the voltages at both batteries. Does the fluctuation move to the domestic battery and the fan perform as normal ?