1991 70hp voltage regulator fun! Working wonky...........

Cannondale

Petty Officer 1st Class
Joined
May 22, 2010
Messages
278
OK. History: (1991C 70 HP Force)

Had stator, old black Merc 9A model, begin to fail, necessitating replacement. So, decided to upgrade the elect. system to the Merc Red 16A stator. This required replacing the voltage regulator as the old rectifier wouldn't handle the new stator. Found a used one for temp. use, but it's having problems holding voltage at 14.4V, lets it rise to 16V at times.

So I bought a brand new CDI unit in (P/N 194-5279, CDI's upgrade/replacement volt. reg. for this year.)

Installed it.....and here's the rub. My elect. system used a 4 wire rectifier. 2 yellow, 1 grey, one red. The new CDI unit is a 5-wire regulator. 2 yellow, 1 grey, 1 red (B+), 1 red (sense....this is a thinner wire than the B+ wire).


CDI says to cap off the thinner wire if using the regulator in a 4-wire setup. OK....done. All other wires hooked up to their appropriate connections. Cranked up the motor....no tach and volt. meter not moving off what the battery reading was before hitting the key, even a minute later. No volt. movement when increasing the engine speed, either.


So, change the connection to the thin red wire from the thicker. Tach now works, volt. meter still doesn't.

Remove it, reinstall old one. Tach now works, volt. meter rises to ~13V at idle within a few seconds of running....and again, it lets the voltage scoot up to 16V when you blip the idle.

So I put the new one back on and wired both reds coming off the volt. reg. to the one red wire going to the engine. Fire back up, expecting smoke, flames.....but get tach working immediately and volt. regulator is now reading "correctly."

So....will wiring it this way to the motor hurt anything?
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: 1991 70hp voltage regulator fun! Working wonky...........

That's strange. There is another CDI regulator P/N 194-5279R. Looks exactly the same as yours except guess what....... the two red wires are tied together! I would say run it as is.
 
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