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Fri May 23, 2008 7:19 am

Finally, I have my 25hp engine together and running! However, I'm having a charging issue.

At idle, I'm getting around 5v. If I rev it slightly, it climbs to 8v or so, but if I really rev it, everything goes haywire: 12v, 18v, 13v, 14v - it's all over the place. I'm testing by connecting the positive lead of my Fluke clone multimeter to the positive lead on the regulator, and the com lead to the battery. I do not have a connection betwixt the battery and the positive side of the generator - do I need to hook that up to validate the test?

So: does anyone have any recommendations on what I can tweak to get my regulator to work correctly?

Also: a big 'thanks' to John Henry for the 11th-hour shipment of genertator spacers!

Fri May 23, 2008 7:48 am

"I'm testing by connecting the positive lead of my Fluke clone multimeter to the positive lead on the regulator, and the com lead to the battery."

Not quite sure what you mean by that.

Start by taking the reg off the gen. Ground the smaller wire coming out of the gen to the gen case. Start the engine and measure voltage between the gen case and the fat lead coming out of the gen. Rev the engine a bit, but nothing too crazy. You should see a range of like 5-20 volts (or more). Do not run like this for more than a minute or so, it stresses the gen.

Next install the reg, connect the wires from the gen to it. Not that the charge current only passes through the reg via a bus bar on the bottom. Fat lead from gen gos right to pos lead on reg (forgot the number, 61?). Now measure the voltage between the gen case and the pos reg terminal. Should get less then 6 at idle, but above 1300 rpm, you should get 7-7.8.

If that passes, hook up the leads to the battery and gen light, and repeat the test. Voltage jump should be a bit less, but it should jump to 7-is over 1300 rpm.

Lastly, check the ground between the gen case and the engine case. It must be good. You can read with the ohm meter, but a more accurate way is to measure voltage between the 2 cases while you rev the engine (with reg and battery connected). Also, make sure your tranny to chassis ground strap is in place...

Let us know what you find.....

Fri May 23, 2008 9:20 am

I'll try these more detailed tests this weekend.

The engine is out of the car right now, hooked up to my starting fixture.

Lastly, check the ground between the gen case and the engine case. It must be good.

How is the generator supposed to be grounded? The oil filler case gasket insulates it from the case.

Fri May 23, 2008 9:52 am

thom wrote: I'll try these more detailed tests this weekend.

The engine is out of the car right now, hooked up to my starting fixture.

Lastly, check the ground between the gen case and the engine case. It must be good.

How is the generator supposed to be grounded? The oil filler case gasket insulates it from the case.

Good question. Best I can tell (in the early designs) it is grounded via the gen strap (painted), and the gen backing plate/fanshroud/engine tin. You can see that depending on how much paint is there, it might not be all that good. That is why you should do the gen to engine voltage "bleed " test. Most of the time it is not an issue however.

I think the best way to fix it if you have it is a small "barb" on the gen stand, that goes through the gasket. You can drill a small shallow hole in the stand top surface, and snip of the tip of a 10 gauge nail (for example) and put it in there. A small ball bearing also works well. Make a small hole in the gasket.

Fri May 23, 2008 4:39 pm

johnshenry wrote: Start by taking the reg off the gen. Ground the smaller wire coming out of the gen to the gen case. Start the engine and measure voltage between the gen case and the fat lead coming out of the gen.

I got 5v @ idle, 14v-18v when revving.

Quote: Next install the reg, connect the wires from the gen to it. ... Now measure the voltage between the gen case and the pos reg terminal.

It's all over the place. 0v - 6v @ idle, 6v - 20v when revved.

Gratuitous picture

Fri May 23, 2008 8:40 pm

Bad Reg.

Engine looks nice!!!!!

Sat May 24, 2008 1:46 pm

I'll see about sending it to the rebuilder mentioned in another thread.

In the mean time, how would I hook it up to a later regulator? I have a couple of late 50's/early 60's, which have a B+, F and a 61 terminal

Fri Jun 06, 2008 1:00 pm

I sent the regulator to Glenn in KS; he said the circuit breaker side is kaput, which renders it unfixable.

Glenn said that he recently had a customer send him a huge batch of regulators, and that several of them were unfixable. The cynic in me sez those are going to show up in the classifieds as rebuildable units for parts Caveat emptor :?

Fri Jun 06, 2008 2:57 pm

Glenn fixed my d regulator and 1952 generator. I was having the generator warning light coming on and no battery charging. Now I have no generator warning light, good charging of the battery, and bright lights (12volt brightness). Seems to have done good work.....at Porsche prices! : )

Sat Jun 07, 2008 11:21 am

thom wrote: I sent the regulator to Glenn in KS; he said the circuit breaker side is kaput, which renders it unfixable.

Glenn said that he recently had a customer send him a huge batch of regulators, and that several of them were unfixable. The cynic in me sez those are going to show up in the classifieds as rebuildable units for parts Caveat emptor :?

I just spoke to a well known collector here at the Classic who resides in AZ, and who told me he just sent Glenn 10 regs of which 5 were rebuild able for around $50 each. From what I know if this guy (the collector) he will certainly not post them in the ads purporting them to be good.

Not to worry...

Sat Jun 07, 2008 11:22 am

Boy, that wiring sure looks nice! :wink: