Page 1 of 1

Molex seems good - charging light still on

Posted: Thu Jul 20, 2017 11:51 am
by stiffler4444
Hi all,

I know this subject has come up many times, but I'm having an issue that I can't seem to understand. I recently replaced my fan shroud mounting plate. Whilst off, I checked out my Molex (as I always had a faint charging light on, but no real charging issues) and found a couple of bad connections. I replaced the offensive spade connections and put everything back together. Now my alternator light is on bright and constant, but I'm having no charging issues. I run mostly short distance, but do stop / start the engine quite frequently, so I figured the batteries would have suffered low charge if there was an issue. I've been running like this for a few weeks now. I'm not incredibly savvy with electronics, but I did presume that if I had a bad connection that my batteries would eventually tell the tale. Any quick thoughts are of great assistance.

tx Dave

Re: Molex seems good - charging light still on

Posted: Thu Jul 20, 2017 9:44 pm
by pinzinator
Bad diodes, bad grounds, loose belt. Pull the alternator and have it bench tested. Then check all connections and grounds. The regulator could be bad, or have a bad ground. The battery terminals could be loose or corroded. That's most of what could cause your electrical problem.

Re: Molex seems good - charging light still on

Posted: Fri Jul 21, 2017 5:59 am
by stiffler4444
Thanks Pinzinator, I will have to pop her out again and see what's up.

Re: Molex seems good - charging light still on

Posted: Fri Jul 21, 2017 8:40 am
by Jimm391730
Having actual voltmeter measurements will tell a world of information beyond the "idiot light". What voltage are your batteries when at rest for an hour or two? (expect ~25V). What voltage do you get when the engine is cranking? (over 20V is good). What voltage do you get once the engine is running, preferably a bit higher than idle speed? (expect ~27-28V). All these should be measured at the battery terminal (not the battery clamp around the terminal). Let us know what you get.

Re: Molex seems good - charging light still on

Posted: Fri Jul 21, 2017 8:44 am
by stiffler4444
Jimm391730 wrote:Having actual voltmeter measurements will tell a world of information beyond the "idiot light". What voltage are your batteries when at rest for an hour or two? (expect ~25V). What voltage do you get when the engine is cranking? (over 20V is good). What voltage do you get once the engine is running, preferably a bit higher than idle speed? (expect ~27-28V). All these should be measured at the battery terminal (not the battery clamp around the terminal). Let us know what you get.
I was hoping you would chime in! I will perform these tests and report the findings.

Re: Molex seems good - charging light still on

Posted: Sun Jul 23, 2017 4:16 pm
by 4x4Pinz
Take a good look at the wiring under the front tin behind the alternator. We have seen many of the wires down to one or two strands left at the connectors to the alternator. Sounds like you have covered the main molex connector already but make sure the back side of the connector is in good shape, so many focus on the outboard side and let the inside go.

Re: Molex seems good - charging light still on

Posted: Sun Jul 23, 2017 5:12 pm
by pcolette
4x4Pinz wrote:Take a good look at the wiring under the front tin behind the alternator. We have seen many of the wires down to one or two strands left at the connectors to the alternator. Sounds like you have covered the main molex connector already but make sure the back side of the connector is in good shape, so many focus on the outboard side and let the inside go.
Very good point! I've found problems there a couple of times. It's relatively inexpensive to replace that internal harness ($23) and is available from SAV (https://www.pinzgauer.com/showdetails.p ... 7121090090) and probably EI also. By replacing that harness you also get a new half of the molex connector. If it looks good except for 1 or 2 wires it's also easy to splice and repair the original if you prefer.

Re: Molex seems good - charging light still on

Posted: Mon Jul 24, 2017 6:07 am
by stiffler4444
4x4Pinz wrote:Take a good look at the wiring under the front tin behind the alternator. We have seen many of the wires down to one or two strands left at the connectors to the alternator. Sounds like you have covered the main molex connector already but make sure the back side of the connector is in good shape, so many focus on the outboard side and let the inside go.
Yes, good observation. I did actually discover when I took, off the shroud, the alternator came with it and the smaller of the two wires broke right off. I replaced the connection and all is good now. We had a big pub crawl on Saturday so didn't get a chance to look at it. Sunday was a hangover day to say the least. :wink:

Re: Molex seems good - charging light still on

Posted: Mon Jul 24, 2017 4:19 pm
by audiocontr
Nice