Acceptable Battery Charge Volt Range -- 15.5 too high?

[mrmolding]

A derogatory comment relating to a tree living, banana eating primate......
BOB RENTON

Check. Another one to add to my collection.

 

[mrmolding]

Not seeing a voltage drop test result on the positive side, from the battery positive post to the ign1 connection (blue wire) at the voltage regulator while under load/operating. Post #8

Voltage drop 0.0 for this test? Possible? All new wiring. Hmm…going to try your second test.

 

[mrmolding]

The FSM clearly specifies the regulator pre-set voltages and where to measure, it's not at the battery.
View attachment 1532330

Ok. So for test 2 above it read 13.5. I then checked voltage at battery again and it read 15.0.

 

[mrmolding]

Ten times on and off turning the little blue dial and we have…

 

[72RoadrunnerGTX]

Ok. So for test 2 above it read 13.5. I then checked voltage at battery again and it read 15.0.

This indicates a 1.5-volt voltage drop between the regulator and the battery with .5 volts as the accepted maximum total voltage drop for this run. While you can compensate for this a bit with the regulator adjustment, you still have excessive resistance in the connections through the ign1 bulkhead connector, ignition switch Molex, ignition switch, ignition switch Molex, ammeter/ammeter connections, bulkhead again, and the fusible link connections. To isolate just where, take more voltage drop measurements at these various points.

 

[mrmolding]

This indicates a 1.5-volt voltage drop between the regulator and the battery with .5 volts as the accepted maximum total voltage drop for this run. While you can compensate for this a bit with the regulator adjustment, you still have excessive resistance in the connections through the ign1 bulkhead connector, ignition switch Molex, ignition switch, ignition switch Molex, ammeter/ammeter connections, bulkhead again, and the fusible link connections. To isolate just where, take more voltage drop measurements at these various points.

There goes my weekend! Thanks as always!!!

 

[hunt2elk]

I went through this same scenario a few years ago on my Duster. Turned out the voltage drop was in the ignition switch. Also had a bad connection on a new M&H wire harness once. Good thing you found that there is a problem, now the sucky part of finding it....

 

[Archie Duiker]

Thanks!!! So all that’s left is the alternator.

Not sure I agree with that. The alternator will easily put out 15 to 16 volts, which is normal. The regulator controls the voltage, so I would think you either have defective regulator(s), or perhaps a bad ground on the regulator or elsewhere in the charging system.

 

[mrmolding]

Not sure I agree with that. The alternator will easily put out 15 to 16 volts, which is normal. The regulator controls the voltage, so I would think you either have defective regulator(s), or perhaps a bad ground on the regulator or elsewhere in the charging system.

Thanks. That was an earlier post. Lots more progress since then, but I'll take any help I can get!

 

[mrmolding]

I like that a lot! They all should have the adjuster on the front. I don't know why the $14 transpo units place it on the back, which is a bit of a pain. Where did you find this red one? Ebay or a website?

So a little more digging on this other Leece-Neville electronic regulator. I found this post on C Bodies and it shows the higher output alternator and adjustable Leece-Neville Voltage regulator. Cool stuff. Not something I plan on doing, but cool to see how they solved it for police cars and other ways to solve this problem. You have to look at most of the thread to see everything.

1972 Polara Texas Highway Patrol

 

[hunt2elk]

I didn't read through the thread you posted, but the ones that were adjustable from back in the day were mechanical. It is always recommended to go with an electronic voltage regulator when converting to electronic ignition.

 

[mrmolding]

I didn't read through the thread you posted, but the ones that were adjustable from back in the day were mechanical. It is always recommended to go with an electronic voltage regulator when converting to electronic ignition.

It says transistor on the front of the Leece — not an engineer but I think that one is electronic.

 

[mrmolding]

Ok everyone! Thanks so much again! Pushed in every terminal, tightened each spade terminal, and I’ve got a voltage drop of 0.2. Going to call it done. I appreciate all of the help! Time to drive it…

 

[JC Boatguy]

Out of curiosity, HOW are you measuring the voltage? With a digital meter, such as a Fluke meter or an old ANALOG meter like a Simpson 260 or equilivant. Analog devices plus the operator's interpretation of the reading is may cause the inaccuracy and the assumed result.....rather than tfying to determine where and if a few tenths of a volt exist. There is no exact, not to exceed number, maximum a lot depends on the battery's state of charge and it's age. Just my opinion of course.
BOB RENTON

I agree with you, I've even had digital multimeters LIE TO ME!!! Sent me on a wild goose chase replacing good alternators, finally i used a different meter and it was perfect at 14.5!

 

[451Mopar]

I didn't read the whole thread, but if you are having voltage drop issues (at the voltage regulator) because of the old wiring, I would power the regulator direct from the battery through a relay that is activated by the current voltage regulator power wire.

 

[mrmolding]

I didn't read the whole thread, but if you are having voltage drop issues (at the voltage regulator) because of the old wiring, I would power the regulator direct from the battery through a relay that is activated by the current voltage regulator power wire.

Thanks! It's all brand new wiring from M&H/Year One. It's all sorted now. Thanks again!