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charge and brake light on, changed alt brush, lights still on

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charge and brake light on, changed alt brush, lights still on

Old 03-03-2019, 08:16 AM
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I finally got around to testing the rest of the wires. Here's what I got ; KEY OFF- thick wire was 12.46 ,thin Red 0, thin White 0. KEY ON- thick White was 12.05, thin Red was 11.80 ,thin White was 3.73.
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Old 03-03-2019, 09:40 AM
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Originally Posted by sc2dave View Post
I finally got around to testing the rest of the wires. Here's what I got ; KEY OFF- thick wire was 12.46 ,thin Red 0, thin White 0. KEY ON- thick White was 12.05, thin Red was 11.80 ,thin White was 3.73.
good job, Dave!
Need to trace thin S wire up to where it splices into thick B wire , most likely near fuse block.
Alt is working, batt is good but SENSE thinks it's not getting voltage, so it gives u charging fault.
Under this fault condition, IF U TAKE CHARGE FUSE OUT, one side of fuse socket would have close to 12V, the other close to Zero. Pls verify this.

What do u read at B and at S when engine is running?
Sorry on smartphone without my reading glasses. lol!

Last edited by RAD4Runner; 03-03-2019 at 09:56 AM.
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Old 03-03-2019, 05:16 PM
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Now i checked the volts at the fuse socket and it was 4.3 v on the left side of the fuse socket. the other side was .34. I Ohmed the thin White wire from the alt plug all the way to the fuse . I believe it read 30 Ohms. could it be the opposite side of the fuse that might be disconnected that might cause the lights to stay on? I also seen this wire disconnected, I don't know what it's for or where it goes to.
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Old 03-04-2019, 12:49 PM
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Originally Posted by sc2dave View Post
Now i checked the volts at the fuse socket and it was 4.3 v on the left side of the fuse socket. the other side was .34. I Ohmed the thin White wire from the alt plug all the way to the fuse . I believe it read 30 Ohms. could it be the opposite side of the fuse that might be disconnected that might cause the lights to stay on? I also seen this wire disconnected, I don't know what it's for or where it goes to.
Dave,

You gotta be specific when describing things.

Exactly What fuse are you talking about here? EXACTLY what position is IG switch when you saw 4.3 and .34? Was engine running? Where did that 8.8 V reading go?

Thin "S" wire does not connect to Charge fuse. Thin white "S" wire connects to Thick white "B" wire at a splice near the fuse block (like I mentioned above).
I repeat: Need to physically trace thin white "S" from alt connector al the way to where it joins thick white "B" wire to find where the break is.

ALSO, That white wire with black stripe is supposed to be ground. Where does the other end go? Do you have have bare, shiny metal contacting bare, shiny metal at your ground point?

Sorry, I don't know what that white connector is for. You also need to tell us what color wires go to it if you want us to help. Again, if you want us to help you effectively, we need to see, what you are working on.

Last edited by RAD4Runner; 03-04-2019 at 12:51 PM.
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Old 03-04-2019, 08:01 PM
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The volts at the charge fuse socket with no fuse and ENGINE RUNNING , was 4.3 v on the left side of the fuse socket and .31v on the right side of where the fuse plugs in. The fuse I'm talking about is the same one you took a picture of in https://www.yotatech.com/forums/f116...s-22re-304868/ . The Left side is the side of the fuse where you have the probe on in the same picture. The White wire with the Black wire that you mentioned is grounded to clean metal. I did not have a chance to see where it goes to. I'll check tomorrow . The IG switch was at the on position.
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Old 03-05-2019, 06:54 PM
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A few more here; With key off, thick alt cable with plug disconnected was 12.7, with key on, 12.1 . Measuring at plug ,where it plugs into alt, the IG wire was 12.1 with key on and with key off it was 12.6
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Old 03-06-2019, 01:45 AM
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Originally Posted by sc2dave View Post
The volts at the charge fuse socket with no fuse and ENGINE RUNNING , was 4.3 v on the left side of the fuse socket and .31v on the right side of where the fuse plugs in. ... The IG switch was at the on position.
Those do not seem normal. I wonder if you also have a brake fault signal and maybe that affects charge light circuit (I need to review schematic).

On mine (Charge fuse removed):
IGN on but engine off (not charging):
Inboard side of charge fuse socket: 0.46 V or close to Zero.
Outboard side of charge fuse socket: 11.8V or close to 12V,

Engine running (charging):
Inboard side of charge fuse socket: 13.24 (close to charging voltage)
Outboard side of charge fuse socket: 12V

Originally Posted by sc2dave View Post
A few more here; With key off, thick alt cable with plug disconnected was 12.7, with key on, 12.1 . Measuring at plug ,where it plugs into alt, the IG wire was 12.1 with key on and with key off it was 12.6
These are normal readings, and your IG circuit is good.

Still need to trace / inspect that thin white "S" wire.
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Old 03-24-2019, 08:18 PM
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I didn't see any damaged wire. Can I just run a S wire from the alt to wherever it's supposed to end up? Also, Is there a ground on the opposite side of the fuse, maybe a ground under the dash?
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Old 03-24-2019, 09:16 PM
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Originally Posted by RAD4Runner View Post
Those do not seem normal. I wonder if you also have a brake fault signal and maybe that affects charge light circuit (I need to review schematic).

On mine (Charge fuse removed):
IGN on but engine off (not charging):
Inboard side of charge fuse socket: 0.46 V or close to Zero.
Outboard side of charge fuse socket: 11.8V or close to 12V,

Engine running (charging):
Inboard side of charge fuse socket: 13.24 (close to charging voltage)
Outboard side of charge fuse socket: 12V


These are normal readings, and your IG circuit is good.

Still need to trace / inspect that thin white "S" wire.
Originally Posted by RAD4Runner View Post
Obviously the alternator was not the problem. See signature.

O.P.
Remove charge fuse and tell us what you see.

REPEAT:
Measure IG, and S voltage as mentioned on my post.
Originally Posted by sc2dave View Post
... KEY OFF-... thin White 0. KEY ON- ,thin White was 3.73.
Originally Posted by sc2dave View Post
I didn't see any damaged wire. Can I just run a S wire from the alt to wherever it's supposed to end up? Also, Is there a ground on the opposite side of the fuse, maybe a ground under the dash?
Putting a bypass wire for "S" wire is a character with big round ears in Disneyland - LOL!

"S" wire voltages should be VERY close to "B" wire voltage. How thorough did you inspect the wire? Did you see there the "S" wire splices into the "B" wire near the fuse block? Did you measure voltage at different points on the "S" wire? Where did you lose 12Volts. Where you did is where the break is. Fix that.

There is no ground on the fuse. Fuses are only on the 12Volt side. Again always be EXACT when describing what you're doing. What fuse? Charge or Engine fuse? Pls see signature.
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