Thinking Cap

[joefrazer]

Ok everyone, put on your thinking caps. My 51 Jeepster now runs but will not charge. I replaced the voltage regulator with a new...not NOS...new, unit but still no charge. I ran a test to see if the generator was working by hooking up a test light to the armature lead and grounding it and the light comes on meaning that the generator is putting out juice. I also tested at the armature post at the regulator and am getting 7+ volts, but still, no charge.

I know it's not charging because no matter what speed the engine runs at, the input voltage at the battery does not change. Also, when the lights are turned on, the gauge shows discharge, even at higher rpms.

I ran another test where I manually closed the cutout and the system then charged so I know I'm completing the loop at that point. I also tested the wiring for continuity and have that.

So, I'm at a loss as to why it won't charge. Any thoughts or ideas are welcome!

[kaiserfrazerlibrary]

I am making the following assumptions here...
1.  You have the correct regulator
2.  You made sure you did not reverse the polarity or magnatize the contacts during installation.
3.  Contacts inside the regulator were checked for corrosion or other problems (taped closed, etc)

How about these ideas
1.  Remove the A and B leads from the regulator and hook up an ammeter to them.  Remove the field lead from the regulator while the engine is idling and touch it to the regulator base.  Increase engine speed slowly and watch the ammeter. If the generator output does not increase on the meter, there probably is still a short or an open wire under the insullation or connectors. 
2.  Connect an ammeter between battery lead & regulator B terminal.  Connect field lead to the regulator F terminal and connect the armature lead from the generator to the A terminal.  Hook in a voltmeter from the A terminal to the regulator base.  run engine a bit higher than idle and read the voltmeter.  If voltage builds up you have an open series circuit...if voltage does not build up the regulator needs adjustment.
More to follow

[kaiserfrazerlibrary]

Here's more...

3.  with the set up ad previously described (last post) remove the cover of the regular and hold the contacts closed, with engine running higher than idle.  If the ammeter shows no charge and your vehicle has a circuit breaker (some Willys models had them) clean contacts and reset the breaker if you have one.  If you have a breaker and it will not reset, the shunt coil is open and the regulator needs repair.
If you do not have any significant generator output, clean the breaker contacts (if you have one, again) and if this does not allow proper reset and operation, replace the breaker.

This is from the Willys Motors Service Manual page 139, section I

[HJ-ETEX]

Jim: I would suggest you are confusing volts & amps. Your test light or multimeter would light up or show voltage just from your battery if the wiring doesn't have a break. If your generator is producing current the voltage would be higher when running than when the engine is turned off. But if your generator isn't putting out enough amps, it still isn't charging the battery.
Now this leads to a story. My Caprice ran down the battery one rainy morning when I went into town. Fortunately my destination was a car parts store so I had them test the battery and then whipped out the plastic and bought a replacement battery. I charged the old battery and there didn't seem to anything wrong with it. So I took the alternator off and took it into the starter shop I partronized. Well, the alternator charged alright - about 10 amps instead of 63 amp. The insulation was worn away on a spot on the field winding so it was grounding out. If I drove to town and didn't use the wipers and the defroster (heater blower), it would supply enough amps to charge the battery to replace the energy used in starting the car.
The charging light on generators and alternators is based on voltage. It really doesn't say anything about how many amps are being produced.

[joefrazer]

Update - I located another generator and after a wap, the issue persists. So, I ran a test on the regulator where, with the engine running, I held the cutout closed. Lo and behold, the ammeter showed a charge. So, now I'm thinking that my new regulator is no good.

[Fid]

Don't forget this - Autolite regulators have the terminal order of ARM, FLD, BAT but Delco are BAT, ARM, FLD (marked BAT, GEN, FLD).  Is it possible you have Delco reg when it needs an Autolite unit?  The FLD wire should be the thinnest one and the BAT and ARM are the thick ones. ARM is by itself, BAT usually has more than one wire on it.  Also, if you get the ground wire swapped with the FLD or ARM wire the AMP light will come on.  It's usually something simple like that so don't over look the easy stuff.

[joefrazer]

Yep...that's all been sorted thru. The regulator is a Borg Warner R121 which was listed as fitting all negative ground 35 amp Autolite equipped 6V generators from 1948 thru 55. Willys vehicles have just a single wire to each terminal and they use an ammeter gauge rather than an idiot light, that's how I was able to tell that I was charging when I closed the cutout points on the regulator. I'm sure it's something simple...it's just finding the needle in the haystack!

[kfnut]

Did you polorize the generator to the regulator after hooking all the wires up ? Any of the old Motor's Manuals show you how . You probable have done this but it was just a thought . i have had to do this on several occasions with cars , tractors ect.

[mbflemingkf]

OK, I'm going to put in a new generator wiring harness from Bob McBride.  What's this about polarizing?  Do I need to conduct this and what is the ritual?  Thanks guys!

[kfnut]

Polarizing the Generator, this is from the Motors Manual 1964.  After the generator is installed on the engine and all leads are connected, the generator must be polarized before starting the engine.  The polarizing procedure depends upon whether the field is grounded externally or internally.  This data is included in the Generator and Regulator Specifications charts in the vehicle chapters.  Having determined which system is used, proceed as follows:  If the generator field is externally grounded, momentarily connect a jumper wire from the "BAT" to the "GEN" or "ARM" terminals of the voltage regulator.  Just a touch of the jumper to both terminals is all that is required.  If the generator field is internally grounded, disconnect the field wire from the regulator and momentarily touch this wire to the regulator "BAT" terminal.
   I included the whole paragraph to explane both methods but i have always used the jumper wire method on my jobs and it works so i assume the KF cars use the externally grounded regulators .
Hope this helps .