High Voltage ?

Ifish2lil

Cadet
Joined
May 30, 2007
Messages
6
My 1996 200EFI Merc's voltage gauge is pegged while running at anything above idle. I noticed the last time out that my GPS had a message that it was shutting down due to high battery voltage. Sure enough gauge was pegged came off plane to idle speed and it was fine. Throttled up and there went the needle up. Any suggestions or diag. procedures would be helpful. Thanks in advance.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: High Voltage ?

REgulator went to electronics heaven. You might also check battery cable condition -- both ends. Loose or corroded connections can upset things.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,788
Re: High Voltage ?

Silver had some good advice. On corrosion, if your regs rely on the housing to engine interface you have a prime candidate there for solving your problem.

Loosing ground reference could make the rectifier voltage to battery higher, even though the regulator (within the module) thinks it's doing it's job.....because it's sensor is referenced to the module case.....but, due to corrosion, the case is not at engine/battery ground.

So clean up all areas of the module case, mounting screws, if it mounts to a plate clean up the plate, replace thermal grease if any, if on a plate, clean up the mounting of the plate to the engine block and all. Remove the screws and clean the whole thing.

If you have a black ground wire coming from the module (probably have 2 ea 20 ampere units....do both) follow the wires to where they are lug tied to the engine block and remove that screw and clean it all up....nice and shiny and brite.

You may not need a new (pair of) regulator after all.

When you are done, and everything is reassembled, spray some Merc Black lacquer over the things to keep the environment out. Don't paint the connections...paint over the completed assy.

Mark
 
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