77 FJ40 Alternator/Wiring Question (2 Viewers)

[bj40green]

Thanks, Rudi! I will get on this tomorrow. So...if the connector to the alternator does not have a wire in the "N" position or IGN on your diagram, then I do not have an external regulator, correct? Because, all I have going into the alternator is the Battery B, the Ground or E and the F wire. I will check the outputs in the morning and see what I get! Maybe I just need to come down to Costa Rica...been dying to get there.

As Claudia said: there should be a black rectangular box with a 3 wire connector on the firewall under the master brake cylinder. Of course there is the possibility that the PO moved the VR.


The wire colors are:
White / black, white / green and green / red
Should look like this


The N terminal is not in use. Only the F and the E terminal are used on the alternator.

Rudi

BTW, We had a huge earthquake today. 7.6 on the Richter scale.
Fortunately no damage to the wife, dog, house and Cruiser.
Lots of damage in the supermarkets.


Saludos de Costa Rica. Land of the BJ40's!

 

[bj40green]

Additional info on my posting #16....
If you do have Voltage on the IGN terminal but not on the F terminal, your VR is defective.
You can open it up and check the contacts for bad contact or being burnt.

Rudi

 

[DSRTRDR]

BTW, We had a huge earthquake today. 7.6 on the Richter scale.
Fortunately no damage to the wife, dog, house and Cruiser.
Lots of damage in the supermarkets.
View attachment 671431

saw that in the news, was thinking of you - glad to hear things are o.k.

 

[Sundance 77 Cruiser]

Just for future reference, here is a link to a color wiring diagram for a 78, i use it all the time to help me on my 76 it's close but not perfect. Take it to Kinkos or some palce and get it printed really large in color and put it on your wall somewhere... it's been a huge help to me

http://www.globalsoftware-inc.com/c...ics/FJ40/1978FJ40/1978fj40_wiring_diagram.pdf

Cal-

Thanks, Cal! I appreciate the link very much!

 

[Sundance 77 Cruiser]

As Claudia said: there should be a black rectangular box with a 3 wire connector on the firewall under the master brake cylinder. Of course there is the possibility that the PO moved the VR.
View attachment 671426

The wire colors are:
White / black, white / green and green / red
Should look like this
View attachment 671424

The N terminal is not in use. Only the F and the E terminal are used on the alternator.

Rudi



BTW, We had a huge earthquake today. 7.6 on the Richter scale.
Fortunately no damage to the wife, dog, house and Cruiser.
Lots of damage in the supermarkets.
View attachment 671431

Saludos de Costa Rica. Land of the BJ40's!

Thank you, Rudi and Claudia! Rudi, glad to hear you are all okay! That is a pretty big shaker...wow.

I think I may have found the VR! I am attaching a picture of what appears to be the VR. Now I need to start checking voltage. I did get a read on the F wire going into the alternator, about 11v, so that is good. I replaced a wire that was connected to the battery, which was in bad shape. Just drove it to run an errand this morning and the batter tested lower when I got back, so still does not seem to be charging. I will work my way in to test the VR (if I have indeed found it!). Let me know if you think that is it.

 

[bj40green]

Looks like you've found it!

Rudi

 

[DSRTRDR]

yes, the square box

 

[Sundance 77 Cruiser]

Hi Sundance,

Here is a pic with the connections.
The circuit is: Turn the key to the "on" position. There should be a voltage equal to the battery voltage on the IGN terminal. This is the input for the VR. Depending on how high this voltage is the output on the "F" terminal is equal to the IGN voltage. When the battery voltage is somewhere around 14.4V (depends on the set point of your VR) the voltage on the F terminal drops to +/- 7 Volts.
So.... if there is no voltage on the F terminal check for voltage on the IGN terminal. No voltage on the IGN terminal, check the fusebox and check the ENGINE fuse. Check fuse and the contact clamps for corrosion.
View attachment 671370

Hope this helps to figure out your problem,

Rudi

Hi Rudi and Claudia! Hope everyone is well. Life got in the way there for a bit. I just got around to testing the VR. The female IGN is testing around 12.1 (battery at 12.4 currently) and the F female is at 4.1 (these are the wires that will go into the VR). The wires coming out of the VR are testing at .3 (both the IGN and F). Does this tell us anything??

 

[bj40green]

Hi Rudi and Claudia! Hope everyone is well. Life got in the way there for a bit. I just got around to testing the VR. The female IGN is testing around 12.1 (battery at 12.4 currently) and the F female is at 4.1 (these are the wires that will go into the VR). The wires coming out of the VR are testing at .3 (both the IGN and F). Does this tell us anything??

I'm 99.9% sure that your VR is shot.
You wrote: The female IGN is testing around 12.1 (battery at 12.4 currently) and the F female is at 4.1
Which tells me: Battery is 12.4. On the IGN terminal it's 12.1. This tells me that there is a current draw. Because you say the F terminal is 4.1 it tells me that the VR is stuck in the half charge position instead of the full charge position. In the half charge position (battery almost full) there is a resistor in series which lowers the output on the F terminal to the alternator to half the battery voltage.

2 options: Buy a new one, around 30 bucks or open the VR and check the contacts for being stuck and burned.

Good luck,

Rudi

P.s. you wrote: The wires coming out of the VR are testing at .3 (both the IGN and F). I think you made an error here. Maybe one of the test leads was not connected.

 

[Sundance 77 Cruiser]

I'm 99.9% sure that your VR is shot.
You wrote: The female IGN is testing around 12.1 (battery at 12.4 currently) and the F female is at 4.1
Which tells me: Battery is 12.4. On the IGN terminal it's 12.1. This tells me that there is a current draw. Because you say the F terminal is 4.1 it tells me that the VR is stuck in the half charge position instead of the full charge position. In the half charge position (battery almost full) there is a resistor in series which lowers the output on the F terminal to the alternator to half the battery voltage.

2 options: Buy a new one, around 30 bucks or open the VR and check the contacts for being stuck and burned.

Good luck,

Rudi

P.s. you wrote: The wires coming out of the VR are testing at .3 (both the IGN and F). I think you made an error here. Maybe one of the test leads was not connected.

Thanks, Rudi. I think I will go ahead and order a VR. Wish I would have known it was shot when I got the alternator; I would have just gotten one with an internal regulator! Do you recommend any sites for Cruiser parts? I think I need a motor for the windshield wipers and was thinking about a shackle lift, as the tires are rubbing the wells on sharp turns.

 

[Sundance 77 Cruiser]

Thanks, Rudi. I think I will go ahead and order a VR. Wish I would have known it was shot when I got the alternator; I would have just gotten one with an internal regulator! Do you recommend any sites for Cruiser parts? I think I need a motor for the windshield wipers and was thinking about a shackle lift, as the tires are rubbing the wells on sharp turns.

Incidentally, I retested the wires coming out of the VR and they are reading .3 or .4 with the key in the "on" position. Is this not a good thing??

 

[DSRTRDR]

cruisercorps, Specter Offroad, Toyota dealer for the voltage regulator

longer shackles from Man-a-fre - or adjust the steering stops

for axle, suspension, steering parts, I would shop with Kurt - cruiseroutfitters

check the Vendor Marketplace section here on MUD

for used parts: Classifieds here on MUD

 

[bj40green]

Hi Rudi and Claudia! Hope everyone is well. Life got in the way there for a bit. I just got around to testing the VR. The female IGN is testing around 12.1 (battery at 12.4 currently) and the F female is at 4.1 (these are the wires that will go into the VR). The wires coming out of the VR are testing at .3 (both the IGN and F). Does this tell us anything??

I read your text as 2 wires going in to the VR and 2 wires coming out of the VR.
There is 1 wiring going in to the VR and that is the IGN wire from the key. This wire should be around 12V (battery voltage).
There is 1 wire coming out of the VR and that is the F wire. This wire goes to the F terminal on the Alternator.
This wire is either HIGH (around 12V) when the key is "on" or the engine is running at idle.
Or this wire is HALF (around 1/2 the battery voltage) when the battery is almost full.
Or this wire is 0V when the battery is fully charged.

I've put some red arrows in this diagram so you can see the path from key to alternator.


Can you point out at what point you tested this 0.3Volt?
If you tested 12V something on the IGN terminal and 0.3V on the F terminal you can asume your VR "dead".

Rudi

P.s. Maybe you tested with the connectors disconnected?

P.p.s. I don't know your electrical skills but there is another way to test this circuit. It's by bypassing the VR with a jumper, a Voltmeter hooked up on the battery and one hand on the throttle. Let me know if you want the full story.

 

[Phares]

Mind blown.
Learning so much! Thanks for answering Sundance's questions. I don't even own a 40 yet and I'm learning.

 

[Sundance 77 Cruiser]

cruisercorps, Specter Offroad, Toyota dealer for the voltage regulator

longer shackles from Man-a-fre - or adjust the steering stops

for axle, suspension, steering parts, I would shop with Kurt - cruiseroutfitters

check the Vendor Marketplace section here on MUD

for used parts: Classifieds here on MUD

Thank you, Claudia! I will definitely be checking out the recommended sites!

 

[Sundance 77 Cruiser]

I read your text as 2 wires going in to the VR and 2 wires coming out of the VR.
There is 1 wiring going in to the VR and that is the IGN wire from the key. This wire should be around 12V (battery voltage).
There is 1 wire coming out of the VR and that is the F wire. This wire goes to the F terminal on the Alternator.
This wire is either HIGH (around 12V) when the key is "on" or the engine is running at idle.
Or this wire is HALF (around 1/2 the battery voltage) when the battery is almost full.
Or this wire is 0V when the battery is fully charged.

I've put some red arrows in this diagram so you can see the path from key to alternator.
View attachment 675503

Can you point out at what point you tested this 0.3Volt?
If you tested 12V something on the IGN terminal and 0.3V on the F terminal you can asume your VR "dead".

Rudi

P.s. Maybe you tested with the connectors disconnected?

P.p.s. I don't know your electrical skills but there is another way to test this circuit. It's by bypassing the VR with a jumper, a Voltmeter hooked up on the battery and one hand on the throttle. Let me know if you want the full story.

Hi Rudi,

I tested .3 at the F and IGN male plug coming out of the VR DISCONNECTED...as for my electrical skills or any gear head skills for that matter, you would be safe to classify me as "buffoon!" This is why your assistance is so greatly appreciated!

 

[bj40green]

Hi Buff.... just kidding, just kidding,

Just for myself to get the picture clear....
The VR was/is connected and you measured 12.1 and 4.1 on the terminals with the test probe in the back of connector (where the wire goes in) ? Right? Like in this picture...


If so than I hereby declare your VR officially dead. Or you want to open it up to figure out what is wrong and if it's fixable.

Rudi

 

[DSRTRDR]

it's not that difficult to look inside - just sayin'

 

[bj40green]

If you want to take a look inside I'll bet that the contacts are black / burned.
You can slide a piece of sanding paper 500 or higher between them and push / pull the paper a few times to clean them.
Flip the sanding paper and do it again for the opposite contact.


Rudi

 

[sggoat]

I now find myself in a somewhat similar situation with my '77. Picked up the truck after a cooling system flush. Drove a few miles to a store, when I returned--battery dead. The rig had been run at idle for some time after the cooling flush--ammmeter reading a little negative. Got it jump started and drove ~10 miles-positive ammeter readings. Got it to battery shop where they said battery was ok, just needed charging, but alternator output was low. Got it home and took out volt reg. Checked all ohmmeter readings according to Toyota Manual. Had to clean the contacts to get the proper readings. The ammeter now shows >30 amps when rpms are >~1500, even though the battery is fully charged-no load. Manual says this condition may indicate the reg contacts may be too wide. Since the contacts were cleaned/sanded, does this mean I need to get a new regulator?(can't make the contacts closer now).
Checked the alt output with engine running-at ~1500 rpm the voltage is almost 20 volts--seems way too high to me. Any help with this would be appreciated.
Gary