Need help, FJ62 electrical/battery/alternator issue (?) (1 Viewer)

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My 1988 FJ62 died on the side of the interstate last night, and I'm not sure where to go next in terms of fixes. Any help is appreciated. Here's the back story:

- 1988 FJ62, 209k miles, original alternator started showing signs of failing (the transmission temp light flashing at idle in traffic, etc) so I replaced it with a Bosch rebuilt alternator (Nippo Denso case was used).

- Battery at least 3 years old, but never had any issues with it.

- On this past Friday, I stupidly left my headlights on while I stopped for lunch. Upon returning to truck, turned headlights off. Truck cranked fine, but power door locks, clock, AC, dash lights, tail lights, rear turn signals, and stereo all did not work. Those things started working when I hit 3000 rpm, but would stop working if I turned vehicle off. Would work again once I hit 3000 rpm.

- Watching volt meter in the gauge cluster, the voltage began dropping. Battery seemed to be charging but not fully. needle never got above 12 volts. Slowly dropped down to 8 volts. Bought a new battery in the 'hood in downtown Mobile (store only had one person working, and they couldn't leave the counter to test my alternator, it was 8PM on Saturday night, and they didn't have an alternator in stock in any case). Replaced battery. Voltage meter peaks back up to below 12V. Battery slowly drains. Same problem with dash lights, tails, etc as above, fixed by revving to 3k RPM.

- Sunday, returning toward home. Battery dies after about 50 miles of travel. Hobble into parts store in BFE, Alabama...wait 8 hours for an alternator to arrive. They also swap out the battery I bought the night before, as it tested as bad. They also test the alternator and it shows the voltage regulator as being bad.
I install a new alternator and put a new battery in in the parking lot.

- On the trip home, the voltage never gets up to 12v. Dash lights, brake lights, tails, radio, ac, door locks - these never come on, even after trying revving the motor to 3k rpm. That doesn't work to reset whatever is wrong.

- Vehicle makes it 225 miles like this but eventually dies. Needle drops faster after nighttime when I have to turn the headlights on. Vehicle dies on side of road, gets towed home.

Questions:
Should my number 1 culprit be the rebuilt alternator? Is there anything I'm leaving out here? Very frustrating. This is the first time my FJ62 has left me stranded, and I feel like the reason is crappy non-OEM parts.

What else should I be looking at? I checked all the fuses as my initial thought was I had blown a fuse. But they all appeared to be working, seemingly confirmed by everything working temporarily after trying the 3000 rpm reset trick.


Thanks in advance.
 
Buy a good alternator, not a cheapo reman.

This could be two issues at once. Sounds like you may have a ground issue or fusible link problem.

Have you touched or worked on anything else before this happened?
 
Buy a good alternator, not a cheapo reman.

This could be two issues at once. Sounds like you may have a ground issue or fusible link problem.

Have you touched or worked on anything else before this happened?


The only thing I've worked on recently was adding in the ARB M002/004 wiring harnesses, but I've run those for 3k miles with no problems...
 
I highly recommend upgrading to a newer 90 amp alternator. Requires trimming of your engine mount on driver's side. Benefit is affordable denso alternators.

90 Amp Alternator upgrade / mod thread
 
Since you got both a bad replacement battery and alternator the first time around, there's no reason to expect the 2 batch to be any better. Buy a quality alternator with good regulator and you should be fine.
 
Figured I would update this thread now that I’ve had time to trace down the issue and fix it.

Apparently, someone in this FJ62 ‘s past saw fit to cut the charging wire at the fusible link and run a crappy inline glass fuse holder. That person also didn’t do a solid crimp. The crimp connecting the thicker charging wire to the inline fuse holder failed, giving an imperfect and failing connection between the alternator and the battery.

I removed the inline fuse and crimped in a 14 gauge fusible link with an eye connector, now run to the positive post of the battery. I also ran a 4 gauge cable from the alternator post to the positive post of battery.

I ran a new positive cable from the battery to the starter, too, because the old one was crappy.

New battery, rebuilt alternator, new cables and fixed the wiring snafu. Now it is running great and charging properly.
 

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