molex connector and dielectric grease

[krick3tt]

The charging light stayed on, and the VR was not the issue (I replaced with spare one, no change) the batteries were relatively new and were able to keep the pinz going till I got home (about 50 miles).

The red wire from the alternator had worn away as it goes through the tin shroud. A small grommet had disappeared and the wire shorted out. It was not apparent as the insulation was whole on top where it was visible but closer inspection showed it had shorted out and the wire was completely separated on the underside....so, no charge getting to the batteries.

I have replaced the wire and am about to put it all back together...can/should I use dielectric grease on the molex connector now that it is clean and ready to reassemble?

Any help will be greatly appreciated.

Morris

[63rover]

Dielectric grease is always a good idea. Depending on where the connector is and how exposed to water and dirt it will be you might want to even shrink wrap it. I was amazed to find out how large the tubes are being made now. They come off easily enough with a pocket knife if you need to get into it.

Have fun.

Cheers, Clive

[krick3tt]

Thanks Clive,

Appreciate the reply. I will do the grease.

edit: Good news...back together and the system is charging as it should. Running about 1500 RPM I get about 27.5 volts at the batteries again.
After a bit of a run I should be back up to my usual voltages. feels good to have accomplished an electrical fix as they are my most difficult.

[Texas710]

+1 for the dielectric grease. Easy to do and will be a bit of preventative maintenance for the future.

If you have not already, I would put in a couple of LED volt meters to watch the electrical system in real time (one for each battery). Jim put up a really helpful post on that topic and it's really not that hard to do, search under "Pinz Voltmeter "

[krick3tt]

Thanks for the tip.

I have a LED voltage display from Marlin P Jones. Thats how I know what my batteries are reading at all times and especially while the vehicle is operating. They are not expensive and worth the trouble to install for up to date info. I just have one for the 24V system but as you say it might be a good idea to get one to monitor each battery separately to check if one is overcharging.

[ako]

Thanks for the tip.

I have a LED voltage display from Marlin P Jones. Thats how I know what my batteries are reading at all times and especially while the vehicle is operating. They are not expensive and worth the trouble to install for up to date info. I just have one for the 24V system but as you say it might be a good idea to get one to monitor each battery separately to check if one is overcharging.

Do you leave your display 'ON' all the time? Or did you add a momentarily closed switch?

Wouldn't think the small unit would draw much current, but wanted to check.

Thanks.

[Brickren]

I tapped my LED meter to the small spotlight plug. (miniature cigarette lighter). This way I can turn meter on/off.

[krick3tt]

AKO,
I have the meter on all the time and it is tied directly to the battery terminals. I have ordered two more that I will connect to each battery to check the individual voltage for checking the reading on each to see if they are both charging equally.
They draw so little that leaving them on will not cause a problem. I also have a switch to disconnect the 24/12 power converter for the Webasto heater so it is not on all the time.

[ako]

Thanks gents.

[Jimm391730]

They (the meters) draw so little that leaving them on will not cause a problem.

Well, it all depends. The little meters from MPJA can draw as much as 40mA (0.04 amps) depending on how many segments are lit (example, showing 18.8 volts draws about double the current that 11.1 volts does). If we assume an average battery of 50 amp hour capacity, the meter will drain the battery in 52 days. But that means that if your truck sits a month, there may not be much left in the battery to get it started.

There are lots of unknowns here but if you use your truck at least every week and run it for 1/2 hour or more (not just down the block and back) then leaving the meter on should not be a problem, but longer times without use or shorter trips could eventually result in dead batteries. Just be aware.

Personally, I hooked my meter (on the dash, in the plastic blank that covers the empty hole) to the ignition switch so it powers off when the truck is off. There is some slight error in the reading (a few tenths of a volt) due to the dash wiring but I don't need to worry about the exact value, I'm only looking to see if things seem different than normal.

But I'm glad people are monitoring their truck's voltage as this is the easiest way to monitor the charging system and batteries.