FJ60 Alternator - Couple of Questions (1 Viewer)

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60series777

60series777

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While running an errand last night I noticed the voltage gauge in my 1985 FJ60 was very low (around 8-10 volts depending on whether or not I had the lights, fan, or turn signals on). The truck had been sitting for about a week so I thought maybe something had been left on or one of the doors had been slightly ajar. I hoped it would charge back up while running but it did not. Today was the same story with very low voltage until I parked at home, at which point I could not start the car. Just a loud click and the starter slowly rotating momentarily, then nothing.

I ran the following tests with a multimeter:

- Battery reading while car was off: 12.6 volts
- Battery reading while running after being jumped (jumper cables still connected): 12.96 volts
- Battery reading while running after being jumped (jumper cables disconnected): 11.3 volts

My questions to you all...

1. Is it fair to assume this is a bad alternator that needs replacing? Battery is new and I don't have any new aftermarket electrical components. I did hook up the carb cooling fan ~2 months ago, but it shuts off right at 30 minutes so I don't think that is it.

2. Can I swap in an alternator from a normal parts store like autozone or o'reillys? I will hang on to my OEM and maybe get it rebuilt down the road, but I need to be driving by Monday. Do these options work?

3. Is the swap pretty straight forward? I'd prefer to do it myself and learn but my skills are limited. I swapped the starter, is it much more involved than that?

Thanks in advance!
 
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1. Yes
2. Hmm, Duralast could be suitable, verify the orientation matches, check voltage regulator at 11 o’clock (looking from front of engine), verify the cables at battery are clean and connections are snug.
3. Easy, you’ve done the starter, which is underbelly work and the alt. is topside. Review the FSM for procedure.
HTH
 
micruz60 said:
1. Yes
2. Hmm, Duralast could be suitable, verify the orientation matches, check voltage regulator at 11 o’clock (looking from front of engine), verify the cables at battery are clean and connections are snug.
3. Easy, you’ve done the starter, which is underbelly work and the alt. is topside. Review the FSM for procedure.
HTH
Click to expand...
Thanks @micruz60. First thing I did was check the cables and clean up the battery posts. No improvement unfortunately. I think I’ll just pull the alternator and bring it to the parts store to test and confirm. That way I can also make sure the orientation of a new unit is the same.

If anyone out there has successfully swapped an aftermarket alternator and can share what they went with, it would be greatly appreciated 👍.
 
This is an AC-DELCO alternator, the voltage regulator has been removed at the top.

IMG_0902.jpeg

I don’t recall if the replacement has an internal regulator.
 
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Check your wiring at to back of alternator. Make sure the connections are good. Test the white power wire that runs from alt to battery. Make sure your fusible links are good.

I had medioce experience with aftermarket china made alternator. Maybe lasted a year. Ended up rolling the dice on another used fj60 alternator which has held up.

The hardest part about taking off the alternator is that you need to remove the pulley to put on the store bought one. They won't have the right pulley. To remove the pulley find the right socket and loosen the pulley nut while the alternator is still in the bracket and the belt is still holding the pulley tight. You'll need an impact wrench to turn it fast enough so your not turning the belt. And space is limited because the radiator/fan shroud is right there in front and in the way. But it's doable. May need a short socket and a short impact wrench.

I suggest you find another used 60 alternator preferably with a pulley... and save yours and take to an alternator shop for rebuild so you have a spare.
 
g-man said:
Check your wiring at to back of alternator. Make sure the connections are good. Test the white power wire that runs from alt to battery. Make sure your fusible links are good.

I had medioce experience with aftermarket china made alternator. Maybe lasted a year. Ended up rolling the dice on another used fj60 alternator which has held up.

The hardest part about taking off the alternator is that you need to remove the pulley to put on the store bought one. They won't have the right pulley. To remove the pulley find the right socket and loosen the pulley nut while the alternator is still in the bracket and the belt is still holding the pulley tight. You'll need an impact wrench to turn it fast enough so your not turning the belt. And space is limited because the radiator/fan shroud is right there in front and in the way. But it's doable. May need a short socket and a short impact wrench.

I suggest you find another used 60 alternator preferably with a pulley... and save yours and take to an alternator shop for rebuild so you have a spare.
Click to expand...
Good point. I will check the wiring at the back of the alternator tomorrow. Everything looked decent at a glance but I didn’t look closely. The other thing that happened is the battery charge light and the brake light came on when I tried to start the truck (even when parking brake is off). I’ve heard that is a telltale sign of dead alternator in a Toyota.

I called Toyota parts center just to see if they had one. They did, but it was gonna cost me $390. Wtf…
 
60series777 said:
Good point. I will check the wiring at the back of the alternator tomorrow. Everything looked decent at a glance but I didn’t look closely. The other thing that happened is the battery charge light and the brake light came on when I tried to start the truck (even when parking brake is off). I’ve heard that is a telltale sign of dead alternator in a Toyota.

I called Toyota parts center just to see if they had one. They did, but it was gonna cost me $390. Wtf…
Click to expand...
Here's one in the classified section: For Sale - FJ60 Alternator - https://forum.ih8mud.com/threads/fj60-alternator.1333599/
 
I would find a good rebuild shop rather than buy a reman from your local auto parts store. It probably won't be clocked right anyways. Install is very easy. Buy that one in the classifieds, have it rebuilt as well for a spare.
 
As said above, check all connections at the alternator and the battery, especially the ground to the body, and check the ground to the passenger side motor mount, and the ground from the head to the firewall.

Likely this is a failing voltage regulator. I would get one from the parts store and slap it on there and see what you get. If that solves the problem order a NOS unit from Vintage Teq Parts because the parts store ones seem to last 9 months. The NOS units … well, the originals seem to go 30-40 years.
 
All connections look good, I don't see any damaged wires and the fusible link looks fine. The alternator should be putting out 14+ volts, right? So I have my answer?
 
Thanks to everyone who chimed in and guided me. My local parts shop was able to source a compatible unit for $128 (I will have to swap the pully but I can live with that), and they offered to take my original alternator to their rebuild guy. I will post here once I have the new one, in case someone has the same predicament in the future.
 
Ok, job done.

As if swapping pulleys was an afterthought....I spent the better part of the afternoon trying to remove the old pulley. The nut came right off with an impact wrench but the pulley itself was absolutely locked on there. Definitely did some damage to the shrowd on the original alternator but I had to pop that sucker off…
IMG_7730.jpeg

From there everything was plug and play. Re-installed new alternator with old pulley, set belt to the same tension as before, jumped the truck one last time, and boom, volts seem to be back where they should be at battery and alternator.
IMG_7732.jpeg


Here’s the replacement I used for anyone wondering.
IMG_7734.jpeg


Cheers to MUD for helping a lousy wrencher accomplish a simple task!
 
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Something still not right…I drove the car last night for ~20 minutes, thought that would be enough time for the alternator to re-charge the battery. I went out to start the car this morning and it just barely turned over. Shut it off and tried once more and the battery did not have enough power to start. Do I need to let the battery charge for longer than that? Anywhere else I should be checking?
 
Connect the battery to a plug in battery charger over night.
A dead battery takes many hours to get charged. 20 minutes of driving won’t do much.
Battery voltage at the battery terminals should be above 14V when engine is running.
 
OSS said:
Connect the battery to a plug in battery charger over night.
A dead battery takes many hours to get charged. 20 minutes of driving won’t do much.
Battery voltage at the battery terminals should be above 14V when engine is running.
Click to expand...
I gave my battery charger away. Regretting that right now. Going to let it idle in the driveway for a couple of hours and see where we're at. Hope it's just a lack of charge and I'm not draining power somewhere...
 
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