Voltage regulator in/on/ or mounted elsewhere?

[boerboel313]

I have dual battery system with red tops, dash voltage gage is reading right between the red and white. See pic.
Battery tester from O'Reillyauto parts store says both batteries are good but need a charge. However, the tester stated that the alternator voltage regulatory is bad.
Do I replace the whole alternator or just the regulator? And is that even an option?

 

[OSS]

The original Toyota alternator on the FJ60 has/had and external voltage regulator screwed into a socket on the alternator body’s exterior. It’s easy to get at and replace. It’s not integrated into the alternator.

Other alternators (such as your non Toyota alternator shown) can have the voltage regulator installed inside the case which is a pain to get at, or mounted externally or mounted off the alternator entirely with wires.

The volt meter in the cab isn’t reliable. Just connect a hand held volt meter to the big battery terminals to measure the voltage at the battery.

Yes - a fried voltage regulator can drop the voltage going into the battery when the engine is running — but so can a fried alternator, which is usually more common.

 

[boerboel313]

The original Toyota alternator on the FJ60 has/had and external voltage regulator screwed into a socket on the alternator body’s exterior. It’s easy to get at and replace. It’s not integrated into the alternator.

Other alternators (such as your non Toyota alternator shown) can have the voltage regulator installed inside the case which is a pain to get at, or mounted externally or mounted off the alternator entirely with wires.

The volt meter in the cab isn’t reliable. Just connect a hand held volt meter to the big battery terminals to measure the voltage at the battery.

Yes - a fried voltage regulator can drop the voltage going into the battery when the engine is running — but so can a fried alternator, which is usually more common.

Txs much. So should I simply replace the alternator? I replaced the one you see about 10 years ago. What do you recommend for my dual battery system?

Thanks again.

Chris.

 

[Seth S]

Txs much. So should I simply replace the alternator? I replaced the one you see about 10 years ago. What do you recommend for my dual battery system?

Thanks again.

Chris.

Your only option at this point is to replace your alternator if its not charging. In my experience the internally regulated alternators fail because their brush packs wear out or the armature on which the brush packs ride on wears out....and most alternators need to be rebuilt to fix this.

For a double battery you should have some sort of control circuit so that each battery is isolated and only one charges at a time.

@ToyotaMatt can set you up with an OEM rebuilt unit.

 

[boerboel313]

And could this be the problem? It's attached to the ground of my starter battery

 

[OSS]

The electrical spade connectors inside your charred fusible link are toast, which increased resistance, which created heat, which is melting the plastic shell, which is smoking, which is depositing more carbon on the compromised connectors, which is increasing resistance, which is creating more heat ….. etc.

Replace your fusible link and your dash voltmeter will display correctly again

City Racer LLC

www.cityracerllc.com

 

[g-man]

That white connection is the battery side of your fusible links. toyota still makes the fusible link, but you may need to replace the battery side of the connection. I had @ToyotaMatt build me a pigtail connection at this end to go from the battery post to the fusible link. Here's a pic

 

[g-man]

I suggest buying a used 55a toyota alternator off a parts vehicle and have it rebuilt. It will last another 30 years. If you do this try and get the tensioner hardware that bolts to the bracket above the alt. so you can adjust tension on the belt. What you have now is missing the hardware.

 

[g-man]

pic of a stock alternator with voltage regulator on it, new fusible links too:

 

[Spike Strip]

That mean green Alternator has an internal regulator. Replacement is $550. MG will rebuild it for you for half that, but their service is veeeeeery slow.

The fusible link, though, looks like that may be the issue.

City Racer LLC

www.cityracerllc.com

If you replace the FL and still have the issue, you may consider an 80-amp 80-series alt which should put out plenty of beans for your setup.

 

[Seth S]

One last thing...and maybe I missed it....but when the truck is running have you measured the voltage off the post on the back of the alternator to a ground point to verify its not charging? And have you verified that there is battery voltage on the alternator post when the truck is off?

 

[boerboel313]

Your only option at this point is to replace your alternator if its not charging. In my experience the internally regulated alternators fail because their brush packs wear out or the armature on which the brush packs ride on wears out....and most alternators need to be rebuilt to fix this.

For a double battery you should have some sort of control circuit so that each battery is isolated and only one charges at a time.

@ToyotaMatt can set you up with an OEM rebuilt unit.

Good to know. I do.

That white connection is the battery side of your fusible links. toyota still makes the fusible link, but you may need to replace the battery side of the connection. I had @ToyotaMatt build me a pigtail connection at this end to go from the battery post to the fusible link. Here's a pic

View attachment 2926352

Great. Thank you. I'll contact them.

 

[boerboel313]

The electrical spade connectors inside your charred fusible link are toast, which increased resistance, which created heat, which is melting the plastic shell, which is smoking, which is depositing more carbon on the compromised connectors, which is increasing resistance, which is creating more heat ….. etc.

Replace your fusible link and your dash voltmeter will display correctly again

City Racer LLC

www.cityracerllc.com

Thanks so much for the link. Will order tomorrow.
Cheers.

 

[ToyotaMatt]

 

[ToyotaMatt]

 

[ToyotaMatt]

 

[ToyotaMatt]