a Better Method to check cable Resistance, is to use a Voltmeter across the cable, from end-to-end.

if there is significant voltage reading across that cable, the terminals are bad, or the cable is corroded.

have the VM connected across the cable before you start the engine.
After the engine starts, the Alternator will be putting out Maximum current for a bit.

if the cable from the Alternator to the Battery measures more than 0.2 volts, fix it.

 

Yep, an alternator running hot is a decent indicator it's working too hard. Enjoy the new Bosch.

 

John.

I checked voltages everywhere and the furthest out from the alt was the driver battery, and it was within a 10th of a volt or so. I measured the alt voltage from the battery negative and the alternator case and across the positve. It was less then 0.02 difference arcross the positve (granted with low output, volt drop would be negligible.

Im going to add a second charge cable to keep the second battery more balanced, as it was showing about 0.01v out from the pass side battery. Probably not required though.

I replaced the lug on the alt anyways, which didnt really do much.

I think the alternator is weak but not dead, and im not going to fret over it anymore. Even went as far to check system draw and it wasnt anything the alt couldnt handle. It was working fine a few weeks ago, and then i started the short commute, and it started to die pretty much right away. It was probably on its last legs, and the short commute finished it. I was thrown off because the pass side positve terminal was bad. That improved power to the starter, but didnt fix the alt issue. The bad power connection could have killed the alt too.

We will see how the bosch holds up. Ill report back to wrap this up once installed. I think my issue will go away as i think my wiring is fine.

 

This video shows what fails in an alternator. Their rebuild kit reasonably priced. The only difficult part is soldering the slip ring since most of us don't have big soldering irons.

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Getting the parts will be to slow. I guess amazon doesnt do cores, so ill have this one as a spare.

My plan was to rebuild it for a spare.

 

I think I would rather pay the extra $100 for a new alternator

 

Or just remove the one on the truck and take it to a good starter/alternator shop for an overhaul. Most decent sized towns will have at least one somewhere. Good option if turnaround time and having the truck down for a few days isn’t a deal breaker.

 

Haha down time is a deal breaker.

Im still driving it, alternator is hanging on for dear life, but its making just enough to keep the batteries at 12.1 volts. Truck starts fine. Infaxt its still starting better than it ever has after the battery terminal change. Can hardly wait to see what it sounds like on full batteries.

The new bosch arrives today. Going to swap it the second i get it. I did get a new one as the bosch was priced well. No core charge to boot.

I dont live in a "decent" sized city. I live kinda near one, but i like the idea of rebuilding it myself. I have lots of tools....lol. A spare would be great to have.

EDIT: if i didnt monitor voltage, i would not know there is an issue. No battery light and voltage still reads well within the normal range.

 

I’d maybe also get one of those USB power port plugs off Amazon that displays your resting (key off) battery voltage. That is more of a battery troubleshooting tool than for the alternator. They should stay up around 12.5 or better sitting overnight…a couple tenths higher for AGM units.

Also not a bad idea is to grab your multi-meter and do some parasitic draw tests. Mine tested around 95-96 milliamps last winter when I was dicking around with it. Enough to pull the batteries down a good bit if the truck sat for a week or longer.

 

rebuilding it yourself is a fun idea if you have the tools and spare time. I didn’t so just took the old one to a shop for a rebuild 2 or 3 miles away. Super small town living, that service might not be available of course.

 

No need for a timer, unless the charger isn't any good on float voltage. There is hardly any power draw from a charger, so you can keep things simple.

 

The timer would be for the block heat. The thing sucks the power. I kinda want a diesel fired coolant heater too.

I have a usb dongle, thats what lead me to a problem. I use tp to confirm(and i can take screen shots easily).

 

Timer for sure on that.

I have a Noco dual plug thingy I am soon to be installing on the bumper. That way it is only one ext cord to the truck. I am on the hunt for an inline, weatherproof 20a switch that can be dedicated to the block heater. That way it stays plugged in all the time for the batt tender, but I can switch on/off the BH as needed.

 

Thats basicly what i wanna do...sort of.

Im building a carputer to add some functionality and on board diagnostics. Im using a raspberry pi 3, and i am going to use android on it. May upgrade to a rpi4

Im trying to figure out a secondary power supply for it that will keep it running wothout the truck batteries when the ignitionis off....and endure whatever Canadian winters can throw at it.

There is a slew of functionality i want to add, and the computer is going to help. I also want to do a dash swap, and i think i could leverage the computer to make a custom dash display....aswell as deal with the new features like heated and cooled seats. Interior swap is down the road...late 2024 at least.

Main thing would be a diesel coolant heater and being able to control the hvac. A recirculation mode would be great. Control the block heater too, and provide an interlock for the diesel heater. A few other things like control of the interior lights in a better fasion like they do in newer vehicles, and cameras too.


I have a marine plug to install as well.

 

Regarding secondary power supply: if being off the battery when you are at a place to plug in the batt tender is your goal, maybe the relatively low draw of an idle Pi could be managed by the tender?

On the BH switching, an alternative is to use a relay set-up. Switch in cab to engage the 120v heater circuit (for some reason I haven't convinced myself to go this route though, even though it is a valid approach). A bank of relays could be part of your revised electric control strategy, for the 12v stuff for sure.