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Voltage Regulator Issue

Nylo

Freshman Member
Offline
I’m having issues with my voltage regulator and was wondering if anyone could shed a bit of light on this.

I have cleaned, and reset this controller to factory spec. The condition is very good with no indication of damage. I have also backed out both regulator, and cut-out adjustment screws completely. I have previously installed a VDO voltmeter to which I’m getting my readings. Its been tested and is correct.

The problem is when hooked-up I’m getting a reading of 12, sometimes a bit below, on a cold motor at idle. When I gradually increase the RPMs it will go all the way to 16, which is the max for the gauge. I have set the regulator adjustment screw to fully screwed in, other wise it will set at a tad below 12 with no increase in the voltage when the RPMs are increased. The cut-out adjustment has no affect fully in, between, or out.

A friend let me install his new controller and I got the same reading of 12, sometimes a bit below, on a cold motor at idle with an increase of the RPMs pushing it to 16. Both voltage screw adjust and cut-out adjust were not touched and left at the factory settings.

The way I deal with this is when the motor is warmed up I run my headlights which sets the volts to 11.5 - 12 at idle, and goes to 12.5 - 13 at 3000+ rpm. Its the stop and go traffic that’s slowly draining by battery. After I have trickle charged my battery I can go for a day and a half before my battery poops out.


1964 Mk1-1/2 Midget.
1275: 12CD-DA-H-11092
Controller: Lucas (spade.) Moss #542-100
 
if u have a 1275, i believe the regulator is built in to the alternator, but that may have nothin to do with ur project, AND i could b mistaken.....zimmmy
 
Could you give us a little more information--like, the voltages you quote are at the battery, correct? Also, is this a generator with the external alternator, the one with a bunch of relays, that is somewhat adjustable? (i.e., not an alternator, which would have a built-in regulator).

The problem you're describing is largely controlled by the regulator--so it seems strange to me that trying a new regulator gave you the same results, which would seem to rule out a regulator problem.

Have you checked to see if the field voltage is getting cut off as the battery voltage rises? It sounds like this isn't happening.

Do you have a multimeter, with which you can check voltages at critical points like the field coil? I suggest dropping ten bucks at Harbor Freight for one of these; it will make electrical troubleshooting much easier.
 
Well, I fixed it and now feel like I'm am an expert on voltage regulators. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

I was making my adjustments too wide. When I moved in small increments it all came together.

BTW: That new regulator my friend had was defective, but he forgot to tell me!

Thanks for the help.

Bridget
1964 Mk1-1/2\
1275
RH drive
 
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