Electrical? Battery? Alternator? Troubleshooting (1 Viewer)

[brhydock]

Hi cruiserheads!
So once again I am looking for some (good ) free advice for my 85 fj60, Bitchy Bertha.
The other day I was driving it home and my headlights seemed kinda dim but she drove fine for about 20 min, I then pulled over to make a phone call and my while she was idling, simultaneously the rpms suddenly dropped super low and then went right back to normal and all my lights dimmed a ton. This happened three times in roughly the course of a min.
I then turned her off (stupid me) and tried to turn her back on and got nothing, just a low eerrr kinda noise. My buddy came to give me a jump ( in his small hatchback mazda, too small of a battery???) but it didn't help at all, still totally dead.
Also my batter is less than six months old, and it was not a cheap one.
Any thoughts/ suggestions?!?

 

[Willard]

Best way is to jump it to get it started and then connect a multi-meter up to it and make sure it is charging. if it is not then your alt may be bad. If it is charging then your battery may be bad. Happens some times. Most auto parts stores can check alt or battery as well, but I always think they just say it needs to be replaced to get a sale.

 

[augirthedude]

Battery connections! Fusible links connections ! Check the fusible link plug for signs of overheating or melting.

 

[swelltimes]

+1 on checking battery and ground connections, and the fusible link.

I went through something similar on my FJ-40 just a few weeks ago. Ordered a new fusible link, cleaned fuse block and replaced fuses, wire-wheeled all ground connections and reinstalled.....and still nothing.

Ended up replacing my battery cables, ground cables, and battery terminals, and that fixed it.

 

[OSS]

The engine can run fine on just a battery alone for a few hours without a functioning alternator until the battery volts get too low. So your alternator isn't charging the battery and the battery got fully discharged as you were driving it. A fully discharged battery usually gets damaged from the experience, but should still hold some charge after its fully charged again. To fully charge a dead battery can take 6-10 hours or longer depending on the AC charger.

 

[morganism]

I would pull off the coil mount, and clean the mounting bolt holes, then run a wire from the ignitor (finned alum case) case to a solid ground. It is a heat sensitive ground connection, and if dirty or rusty, it will lose your ignition grounding.

If still just clicks, either climb under and move the flywheel thru the inspect port, or loosen starter bolts, and tilt it to move the teeth a bit.
If you are level, sometimes you can just shove the whole truck in 4th, and it will move that flywheel a bit.

Go under dash, reset the starter relay w a paperclip (think it is one of the two round ones) and give it another whirl.

 

[FJ40Jim]

1st thought: check battery voltage with an accurate DMM.
If is low, then charge battery.
If it is good, then do more troubleshooting of starter circuit.

 

[morganism]

Tool R Us points out..

"The 1FZ rigs have a ground wire that goes from the fender well to the coil bracket, the intake and the motor lifting bracket, so well grounded."

 

[emac]

Voltmeter and check battery voltage. Charge it and it should be 12.5 or so. Start the car and check voltage with car running and it should be at least 14. If voltage is dropping as it runs, then alternator isnt charging. On my 88 fj62 I went through two parts store alternators that were garbage right out of the box. I bought a Toyota factory refurb and it has worked perfect.

 

[brhydock]

Thank you all so much for your input. It was the alternator that was causing the issues. I found a local guy to rebuild it and 90 bucks later, old Bertha is running like a champ!