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Renix Voltage Regulator Opp voltage spec?

Ecomike

NAXJA# 2091
NAXJA Member
Location
MilkyWay Galaxy
IIRC my Renix rigs have been operating at 14.7 volts at the battery (engine running) for a decade, but my memory is not what it use to be IIRC, LOL.

They would hold 13.7 volts with every electric gadget I could turn on at max, unless the Alternator lost a diode set, then it would run from 12.7 to 13.7 volts depending on the load, and no higher that 12.7 volts with a dead alternator-voltage reg package. On the Renix, 87-90 jeeps the voltage regulator is in the alternator.

This week I noticed that with no loads I am getting 14.0 volts at best, usually 13.9 volts running, and with head lights on, AC blower etc on Max, I am getting 13.7-13.75 volts, so it is not dropping like it would with a bad diode set, under load, but also not running up to 14.7 Volts with no load like I think it use to do. I have never had a Renix voltage regulator problem before.

Note to self: Make sure the battery is actually fully charged next!!!

So does anyone know what the normal voltage regulator range is for the Renix?

If this is a problem, what would be the common cause, other than the known ground and wire issues with Renix rigs?

Should I even be concerned? The head lights are fine at 13.7 volts.

I never had one hold such a narrow range voltage between no loads and peak loads before. The rig and alternator are stock, 90 or 100 amp.
 
How are you getting these numbers? Do you have a DMM hooked up or are you going from the dash gauge?

The numbers look fine. Over time, the battery will change and cause these to change.

Personally, running with 14.7 all the time is a touch high in my experience.
 
DMM reading at the Battery posts.
 
The numbers look fine. Over time, the battery will change and cause these to change.

Personally, running with 14.7 all the time is a touch high in my experience.

x2

13.7 is better for the battery. But, (just to feed your OCD, :laugh3:) there is the possibility that the field brushes may be starting to wear out. Also the alt case ground may be in rough shape

Try not to be too picky Mike, the girls are old and well within their rights to slack off a little....:roflmao:
 
The battery, clamps, and alternator are not that old, and wire ends cleaned not long ago. As far as OCD goes I noticed the dash gauge was showing a lower value than I had ever seen under normal conditions with the AC blower on Max, head lights off, that is why I check the number at the post, and they were not what I knew to be normal (IIRC) for my Renix rigs. One is being scrapped so I can not compare it (great beast for 10 years got rolled by others), and the other I have not checked yet.
 
Last edited:
https://www.autobatteries.com/en-us/battery-testing-and-maintenance/car-battery-voltage-and-testing

Looks like my memory is right, it use to be 14.7 volts, low load, so now I need to find out what changed.

"Fully charged automotive batteries should measure at 12.6 volts or above. When the engine is running, this measurement should be 13.7 to 14.7 volts"

While I am in that range still, it use to be 14.7 at low loads for 12 years on mine, so something has changed, early warning sign something is going bad IMHO. I will check everything, but I am wondering if the voltage regulator in the alternator is doing it. I doubt it is the battery. But Old_man is the EE expert on them.
 
If it's an internal regulated alternator, is there the possibility the V/R is defective and going flakey? "Recent" electronics in my experience have been subpar as of late.
 
If it's an internal regulated alternator, is there the possibility the V/R is defective and going flakey? "Recent" electronics in my experience have been subpar as of late.

That's partly was I was getting at in the question. That or a connection on it getting loose and noisy.
 
So far it looks like the battery was not fully recharged yet, from being drained in test runs, frequent starts while debugging that miss recently. It got back up to 14.4 volts the next day with little load and a nice 13.9 volts with all the loads on. So you are right the battery condition was affecting it, in this case it was using a lot of the alternator capacity to top it off. And that drain dropped when the other appliances were loading it down to where it still held 13.75 Volts with an incompletely charged battery.

First time I think I have run across this variable, nice to still learn interesting stuff the easy way,:laugh: LOL.

Thanks!!!

How are you getting these numbers? Do you have a DMM hooked up or are you going from the dash gauge?

The numbers look fine. Over time, the battery will change and cause these to change.

Personally, running with 14.7 all the time is a touch high in my experience.
 
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