Overcharging/overvoltage

[241steve]

has some aftermarket accessory been feed off it? Its switched by the ignition switch. find the wiring diagram then stick your head under the dash is my guess. In saying that if that was the case it would of been doing it since the accessory was added unless its on turned on sometimes. Where did you test the resistance of the sensor wire from back to positive battery terminal with the key on and positive disconnected?

[Bannisterr]

Hey Steve I dont believe any accessories have fed off it, on my wiring diagram it looks like it runs straight from the alt into the engine bay fuse box and then presumably to the positive. (Sense wire/white)

I only tested the voltage drop off from the positive terminal to the plug. Wasn't able to get a good reading of the resistance, assuming that was because of user error.

What would be the best way measure the resistance between the plug and positive terminal? I've found alot of conflicting info about this online.

Thanks mate

I'll report back tomorrow with my findings

[Chancha_Blanca]

Bannisterr, txt or call Jamie on 0416 935 867, he is located in Tuart Hill (NOR) and does reco/exchange alternators and has stock too.

look him up on Gumtree too.

[Bannisterr]

Hey mate, I actually got this alternator off Jamie. Really nice bloke.
I'm pretty confident at this point its a wiring issue not an alternator problem

[241steve]

lift the positive batt terminal and buzz from the battery positive to the sensor wire with the ignition in the run position i think a fuse is blown

[Bannisterr]

Thanks Steve, I'll give that a go and post my results

[Bannisterr]

Hi all, apologies for posting on this thread after such a long time. I figured it may help someone in the future.

During this study break, I finally got time to dig deeper into my overcharging issue. After alot of testing, I narrowed the issue down to the alternators sense wire. It had significant voltage drop, forcing my voltage regulator to over compensate on charge.

The harness which housed the wire seemed to have rubbed on the sump. It was very hard to see, but after cutting back the harness I found the sense wire had a small green dot on it. Cutting back the insulation exposed about 5mm worth of completely corroded wire. (Unsure how to attach photos sorry)

After replacing this wire, all the issues were sorted. No more overcharging and no dash battery light. Thanks to everyone who previously commented suggestions!

[Rob_Wood]

Hi all, apologies for posting on this thread after such a long time. I figured it may help someone in the future.

During this study break, I finally got time to dig deeper into my overcharging issue. After alot of testing, I narrowed the issue down to the alternators sense wire. It had significant voltage drop, forcing my voltage regulator to over compensate on charge.

The harness which housed the wire seemed to have rubbed on the sump. It was very hard to see, but after cutting back the harness I found the sense wire had a small green dot on it. Cutting back the insulation exposed about 5mm worth of completely corroded wire. (Unsure how to attach photos sorry)

After replacing this wire, all the issues were sorted. No more overcharging and no dash battery light. Thanks to everyone who previously commented suggestions!

Why do you think it rubbed on the sump originally? Have future occurrences been prevented?

[Bannisterr]

It's an 05 ex miner so I'm assuming over the years it rubbed against the sump until it wore through. It's odd though, the harness was fastened using the factory harness clips. I'm curious if all early model hiluxs have this part of the harness resting on the sump.

I've replaced the flexible conduit and positioned the harness away from the sump by extending the factory clips.

This car is a gift that keeps on giving