Parasitic Battery Draw

[ElCheapo]

Just disconnect the big grey fusible link thick white wire in the fusible link cover and the multi-pin connector on the back of the alternator. Those are the only connections to the alternator. If the measured current drops, then you know it's the alternator (the diodes are built in to the regulator inside, in case you didn't know).

I will try this when I go back to work soon, we have crazy high tech multimeters there that get calibrated every 6 months so I trust a reading from one of those more than my own.

 

[LandLocked93]

So when the issue initially arose the battery would die within a few hours after letting the motor run for a while. I replaced the battery and it didn't get any better. I didnt have a multimeter at the time so I never got a chance to check for parasitic draw. I replaced the alternator and the issue seems better, but not fixed. It can sit for a few days before it goes flat now. Today I tore the alternator to battery harness apart again and I noticed that what @LandLocked93 said was somewhat true for mine, the heat shrink had fallen apart and the terminal crimp was very close to the alternator case so I re-heat shrinked it. I also noticed that the wiring on the connector for the back of the alternator had some missing shielding in it so I wrapped them in some aviation grade antichafe tape and then put a new wire shield over that. I did some resistance checks on the wires and found everything to be in good order so far. Will report back if I find anything else.

Good deal.
If the issue remains, do you have trailer wiring?
edit:also, are you still working with a RedTop bat? I know they were good at one time (I had one in the 90s and it was fine), but there was a period of time (several years in the 2010s) where their quality was quite poor, lasting less than 2 years usually.
Dunno if that's resolved by now or not, but repeated charges and drains on a poor quality unit would destroy it in short order.

 

[ElCheapo]

Good deal.
If the issue remains, do you have trailer wiring?
edit:also, are you still working with a RedTop bat? I know they were good at one time (I had one in the 90s and it was fine), but there was a period of time (several years in the 2010s) where their quality was quite poor, lasting less than 2 years usually.
Dunno if that's resolved by now or not, but repeated charges and drains on a poor quality unit would destroy it in short order.

I have a very poorly installed OEM toyota towing wire harness. I would remove it but I do use the towing harness pretty regularly. I'll have to go through it and see if I can clean it up at least. So I do have that red top and its been through a very hellish winter where it was dying and getting jumped very regularly. I was not aware that optimas quality had dropped, ill probably just grab a NAPA replacement for it when I get my finances in order.

 

[ElCheapo]

So I did a 5,000 mile road trip sleeping in the back of the cruiser the whole way. Truck ran flawlessly other than the PHH literally exploding while in downtown Seattle. The battery charge issue seemed to not be bothering the truck. Sure enough the moment I got home and parked it for 2 days it wouldn't start due to a dead battery. I took the truck to autozone and got a clean bill of health on starter and alternator. He did say that the battery was only hovering at around a 95% charge which kind of sucks seeing as the truck had only been parked for about 5 minutes after driving for several hours.

 

[BILT4ME]

So I did a 5,000 mile road trip sleeping in the back of the cruiser the whole way. Truck ran flawlessly other than the PHH literally exploding while in downtown Seattle. The battery charge issue seemed to not be bothering the truck. Sure enough the moment I got home and parked it for 2 days it wouldn't start due to a dead battery. I took the truck to autozone and got a clean bill of health on starter and alternator. He did say that the battery was only hovering at around a 95% charge which kind of sucks seeing as the truck had only been parked for about 5 minutes after driving for several hours.

Place a multimeter on the battery. If it reads anything lower than 12.5V, replace it.

Also, if you still have the OEM Toyota trailer harness in the RR fender, replace it, as you are on borrowed time before it melts down.

I replaced mine with one from eTrailer.com and have had it installed for 6+ years and it works great.