1979 70 merc charging system

[martinrobbins]

this is a 1979 70 hp merc serial #5235661 .i,m just wondering if there is a charging system on this motor and if not how can i put one on without hurting any electronics ?
would like to spend alot of time on the river this year and i don,t want to worry about the battery.:redface:

 

[Chris1956]

Re: 1979 70 merc charging system

The parts list for that motor shows it has a charging system. You need to make sure it is working. Run the motor on muffs or on the water. Measure the voltage at idle and then rev it up a bit. If the voltage rises, the charging system is working. It will only charge 6-9A at WOT, so do not expect a lot of charging.

 

[martinrobbins]

Re: 1979 70 merc charging system

do i check the charge at the battery or is there somewhere else to test for voltage?

 

[Droll]

Re: 1979 70 merc charging system

do i check the charge at the battery or is there somewhere else to test for voltage?

Measure the voltage across the battery BEFORE starting the engine, then start the engine and see if there's any change, should rise ... ( might need some rpm so take the boat out for a spin... or if that's hard to do you could hold the engine at high idle a bit ( MAX 1500 rpm )) .

Remember cooling for the engine if testing on land !! .

Arne Kjetil