View Full Version : voltage regulator=cause draw

09-06-2010, 08:49 PM
One of the reason I rewired the Midget I was searching for an electrical draw. I knew my regulator was not putting out. but I think it is the electrical draw.

As I finished installing all the new wiring under dash everthing was fine until I hooked 12V from my starter switch to the Voltage regulator, I got a terrible draw immediatally.

I am going to order a new regulator tomorrow from Moss. but is this resonable? Can a regulator have a dead short?

I have opening the regulator up for inspectionand there are no signs of shorts

09-06-2010, 10:33 PM
Yea can. I no nothing about them really, I consider them a remove and replace item.

09-07-2010, 06:26 AM
The current from the battery goes through the regulator to the rest of the car. So, if you get a heavy draw when you hook up the regulator, it's not necessarily a problem in the regulator.

It's possible for the short to be inside the regulator, but pretty unlikely. Something would have to come loose, and I'd think you could see that easily when you took the top off.

09-07-2010, 08:36 AM
Ahh, Steve has spoken. Thanks Steve we all appreciate your wisdome on all things electrical.

09-07-2010, 10:46 AM
It is doing it with nothing eles hooked up to regulator except my hot lead going in

09-07-2010, 11:30 AM
And Steve said "if you get a heavy draw when you hook up the regulator, it's <span style="color: #FF0000"><span style="font-weight: bold">not necessarily </span></span>a problem in the regulator."

Guess what, I would replace the regulator. I expect this is one of those cases where the prob is internal to the regulator.

09-07-2010, 01:15 PM
Well, if that's what's happening, it seems pretty clearly to be the regulator. You really should be able to see where the problem is, though.

Did you look at the underside? There are a number of connections in that narrow space under the regulator, visible only when you take the whole thing off. It's not impossible that something is wrong there; then, it would be easy to short to the body.

But, in any case, if you've hooked up only the battery-to-regulator lead (A or A1 terminal, I forget which) and you get a large current when you do it, it can't be much else.

09-07-2010, 03:05 PM
I am going to take a stab at it again tonight

From what I understand from web searching this is how the regulator for a early 1275 Midget is wired. Regulator part # 542-101 in Moss cat.

A1 Hot wire from Starter switch (Brown)

F Field to generator (small wire)

D big wire to generator (Brown yellow)

E Ground (Black wire I assume)

The E has thrown me, Has my research served me correctly. Currently my voltage regulator is not grounded. could that be my problem?

09-07-2010, 07:36 PM
E is definitely ground, but I cannot say whether that is your problem (although things are generally grounded for a reason). To elaborate on what one of the previous posters was saying, you must make sure that the A and A1 terminals are not being accidentally grounded to the body. At least on my regulator these were bare wires on the underside of the regulator, so this is not out of the question.

That would give you a serious draw for sure!

You might find this pdf on the topic of voltage regulators to be helpful.
Voltage regulators 101 (https://www.homepages.donobi.net/sufuelpumps/Other_Subjects/Electrical/General/Voltage_Regulator_101.pdf)


09-07-2010, 08:09 PM
Thanks for confirming that,

09-07-2010, 09:35 PM
Well I should of had a clue when the wiring on the rest of the car was a mess,

It just looked right, the wires to the regulator. never assume

No more electrical draw.I removed all the wires from the voltage regulator, then removed VR from the car, inspected for shorts etc.. reinstalled VR and wired "correctly" and install a ground wire (that wasn't there before)

No more draw. to late here on the east coast to crank up and see if it is charging..........just hope generator and VR are OK from being wired wrong