Voltage drop -- how is this possible?

[Nacho-RT74]

I don't see a huge voltage drop there.

This prooves the MAD electrical "fix" doesn't necesarily fix anything.

Problem is elsewhere.

Regulator maybe?

 

[JG1966]

The video above may help.
Try this, unplug the two wire terminal at the voltage regulator and let it hang. Run a bypass wire from the battery positive post directly to the terminal on the voltage regulator that the blue wire goes to, jump the green wire in the regulator wiring plug to the post it is supposed to go to. Doing this will bypass all the wiring and connections between the battery and the voltage regulator. start the engine, if your charging voltage comes down to normal, 13.8 to 14.2 with a fully charged battery, you have a bunch of high resistance connections in the wiring. Such as ignition switch run contacts, bulkhead connector terminals, fuse block terminals, etc.

Thanks Paul. I've watched that video before. It didn't help a lot. But I have read a bunch of posts on other sites about doing what you described and how to "jump" the voltage regulator. Yours is the first one that I could actually understand. I'll give that a try

 

[JG1966]

I don't see a huge voltage drop there.

This prooves the MAD electrical "fix" doesn't necesarily fix anything.

Problem is elsewhere.

Regulator maybe?

Thanks Nacho. I did the Mad electrical bypass more to eliminate the bulkhead and ammeter trouble spots than to fix the voltage drop. The regulator is good. I've bought two new ones and tested them.
I guess I should be asking -- Is charging at 14.95 that big of a deal? I've been driving like that for three years (though I don't go on long road trips) and never had an issue with battery or anything.

 

[72RoadrunnerGTX]

To be clear, “full fielding” the alternator is primarily used to diagnose alternator operation or the elimination of inop regulator. Normally also used with clamp-on carbon pile (adjustable load) and ammeter to determine alternator current output. In this case it’s pretty clear that is not really in question. A slight charging over-voltage at the battery resulting from a voltage drop in the reference voltage at the reg is a different matter altogether.

There is a reason the adjustable electronic voltage regulator is being produced in the aftermarket.

"Ammeter trouble spots" Ah, the dreaded “ticking time bomb” ammeter. No, can't agree with that.

 

[RJRENTON]

To be clear, “full fielding” the alternator is primarily used to diagnose alternator operation or the elimination of inop regulator. Normally also used with clamp-on carbon pile (adjustable load) and ammeter to determine alternator current output. In this case it’s pretty clear that is not really in question. A slight charging over-voltage at the battery resulting from a voltage drop in the reference voltage at the reg is a different matter altogether.

There is a reason the adjustable electronic voltage regulator is being produced in the aftermarket.

"Ammeter trouble spots" Ah, the dreaded “ticking time bomb” ammeter. No, can't agree with that.

AMEN.....
I totally agree with your premise. A slight difference in the regulated voltage (observed) vs the FSM (stated allowable range) is caused by either a defect in the regulator's internal sensing network (thermally compensated voltage divider or leakage in the controlling transistor) OR a slight voltage drop in the regulator's sensing inputs supply, as noted previously by others. Once again good old Nacho doesn't have a handle on the specifics.....
BOB RENTON

 

[Nacho-RT74]

I have had similar voltage drops at several points and never have had that voltage at the battery with engine running.

Just sharing my experiences. Not trying to be a smartass.

I bet you dozens of members will read similar voltage drops around and won't get that voltage at battery.

Regulator can be "operative" which could not mean is actually working propperlly.

Just my two cents, once again not trying to be a smartass or kicking anybody *** out.

 

[JG1966]

I have had similar voltage drops at several points and never have had that voltage at the battery with engine running.

Just sharing my experiences. Not trying to be a smartass.

I bet you dozens of members will read similar voltage drops around and won't get that voltage at battery.

Regulator can be "operative" which could not mean is actually working propperlly.

Just my two cents, once again not trying to be a smartass or kicking anybody *** out.

Thanks Nacho. I've ordered an adjustable voltage regulator and going to give that a try.

 

[JG1966]

I just wanted to give an update and thank everyone for their help. I installed an adjustable voltage regulator and after adjusting it a little I'm at 13.98-14.0 charging volts at about 80 degrees ambient temperature, well within the FSM specs. I'm still getting about .74 voltage drop at the blue alternator wire, but I can live with that. All of the connections are much cleaner now and I'm not getting to 0.0 voltage drop with many original connections and wires. Thanks again!

 

[Nacho-RT74]

I bet you changing the VR for another stock replacement non adjustable will get variations too maybe perfect, or maybe not, but still diff results still with that same "voltage drop" ( which I still say is on more less expected rates, depending also on the multitester accuracy ). As mentioned, the working conditions doesn't mean is correctly working and we all know about the quality issues latelly about electrical components nowdays. There is a guy at DC.com who had to change 3 times its temp sender to get one propperly working. One of them was on 120-250 ohms rate while the correct is 10-70 ohms operating rate.

Good to know the adjustable one made the job to your expectations