This darn phantom battery drain (1 Viewer)

[koszowskima]

Hey all, I have been wrestling with this issue for almost 4 months. I will walk you through it to the best of my ability...

4 months ago:
After trying to start the car one morning I turned the key and nothing happened. After jumping the car/trickle charging it I got it running. Died later that week.

Went to Costco to get a brand new interstate battery as the other one was 4 years old. Working for a bit but died/wouldn't start probably a week later.

2 months ago:
Ripped out the 3rd party alarm system as those are known to have some problems. After charging the battery up and then trying to start it I got nothing (however the battery read that it was full).

After some poking and prodding, it turned out to be a grounding error near the battery (All seem fixed). To ensure this fix we resecured the wires to the terminals, got new terminals, and got a new battery strap because there was some rattling around.

No problems for almost 2 months. The truck was riding great, starting like a champ, and finally seemed reliable.

2 weeks ago

I hadn't driven the truck in about 2 weeks and went to start it and nothing (battery was reading dead). Checked all the connections and they felt solid. Jumped it and it started up again. Drove for a little while. Next day nothing. trickle charged it for 6-8 hours. Few, days later nothing.


ORIGINALLY, the problem seemed to stem from both a trickle drain and bad connections/the battery getting jostled. After fixing the former, all seemed great and I was ready to move on to big and better things.

Current:
I have it up on a lift getting ready to swap the suspension (New OME), and I have it hooked up to a battery tender

The only thing in that truck that draws power that isn't original is the radio system. Has anyone had problems with this in the past? Open to all ideas...

 

[OSS]

Step 1:

Is it a FJ60 or FJ62?

 

[koszowskima]

Step 1:

Is it a FJ60 or FJ62?

Sorry, 1987 FJ60

 

[micruz60]

Yes^(OSS) also, are the belts for accessories all taut, not too tight, not loose, and was the alternator charging when you had good ops?
Do all interior cabin lights work / door switched?

Good that you removed the third party alarm system, as that probably tapped into / caused battery drain. Still would be prudent to have some sort of anti-theft system.

 

[koszowskima]

Yes^(OSS) also, are the belts for accessories all taut, not too tight, not loose, and was the alternator charging when you had good ops?
Do all interior cabin lights work / door switched?

Good that you removed the third party alarm system, as that probably tapped into / caused battery drain. Still would be prudent to have some sort of anti-theft system.

not too long ago I had it checked out at Japanese Auto Shop here in Denver (known to be good with '60s) to replace the berfs, and I had them check out the whole rig. They never mentioned belt problems (but a possibility).

It never presented as an alternator problem. On longer drives, it sat at 12 V and never experienced problems turning on lights or using blinkers. The more I drove it the more reliable it was. Only after sitting for a but did I run into problems

Yes, the lights work, the knob that brightens the dash works, and the dome light responds to on, off, and door.

 

[micruz60]

Okay- usually, when driving, with no accessories on (wipers, heater blower, headlights etc.) the dash alternator gauge should read around 13.8 V

I believe your alternator may not be up to standard, but that does not rule out a parasitic drain elsewhere. You could pull the alt and take it to the bench and test it, since you are in the shop now.

HTH

 

[YooperCruiser]

To check for an electrical drain pull a battery cable off the battery(doesn't matter which one) and put an ammeter between the cable and the battery post and measure the drain. If you do measure a drain then pull fuses one by one till it dissapears, now you know which circuit it's in and can hopefully track it down. You can also use a test light in place of the ammeter.

 

[CardinalFJ60]

just for shiggles....pull the dome light fuse prior to letting it sit again for a spell. then see if that did it. there are a couple of typical culprits in that circuit. YMMV

 

[60Works]

Measuring circuits one by one is best.

Once you've found that it is in the cabin lighting; pull the bulb out of the cargo light and check there.

 

[CardinalFJ60]

my bet is the carb cooling fan relay. it's in the dome fuse circuit. took me like 3 hours to figure out...in the end it wasn't 'letting' go and would put little drain. I just unplug and re-pulg the fuse if it's gonna sit for a while.

 

[cruiserpilot]

voltage regulator? check grounds everywhere. internal clock or on radio? pull plastic covers and check ignition is actually cycling off
on steering column.