Testing a voltage regulator

[yuioutta]

Working on my 96 Merc 260 again. Is there any way to test the voltage regulator? I have found tests for the rectifier and the stator but for some reason cannot find any test or info on how to test the regulator.
Thanks, Shawn

[j_martin]

Which one is it? 40 amp water cooled, dual 5 or 6 wire, single 5 or 6 wire, or the little one that goes with a rectifier?

John

[yuioutta]

It is the the little 2 wire one that goes with the rectifier. Thanks

[j_martin]

If it boils out your battery, it's bad. As I remember, that part is no longer available. If it doesn't work, and you don't have enough load to keep the battery from grossly overcharging, you can put on any one of the 5 or 6 wire regulators as a retrofit, replacing both the rectifier and the regulator. The yellow potted ones were marginal, the black ones are better. They are readily available used.

hope it helps
John

[dez nuts]

If it is a 260 with a fuel pump running constantly take it off and don;t run any reg on the motor it will not over charge your battery with the fuel pump running and you running trim now and then they don;t charge enough to hurt the battery with the pump running all the time
:thumbsup:

[YELLOWSS]

not to hijack this thread, but do you just wire the wires together and not run a regulator????? sounds like it would help for a 260!!!

[j_martin]

not to hijack this thread, but do you just wire the wires together and not run a regulator????? sounds like it would help for a 260!!!

If it has a diode type system, the regulator is a shunt type, just bleeds the excess to ground. On a 260 it isn't needed, but if it's good, it's harmless. The fuel pump draws enough to keep the battery from cooking without regulation.


hope it helps
John

[yuioutta]

Hey thanks for the info guys. It does have an electric fuel pump so sounds like I wouldn't need it. My problem was undercharging and not overcharging. I did find a bad rectifier but just wanted to test the regulator if I could. Shawn