Alternator wires and light woes.

[ouiseyg]

What a numbpty I have just had the bearings in my alternator replaced and I can not remember where the black lead with the eyelet goes. Its on a 93 4.0, with the unit fitted as if you are sat in the car the wires are from right to left.
The main brown wires fit on the right stud.
The smaller brown wire fits on the middle stud (no captive nut on mine)
The "w" terminal has a block with a spade bolted to it (but not used) but I cant remember if this black wire bolts to this stud or to where the little black radio suppressor fits onto one of bolts that holds the unit together. If someone could have a look at thiers it would be a great help.

Also any thoughts on why the charging light on the dash still glows very dimley even though the alternator is charging at 14.1 volts checked at either the back of the unit or even over the battery. I do not have the 100amp fuse in the normal underneath place but nor have I located it in the footwell yet either. But surely if there was a problem here the charge would not br getting to the battery? The unit was checked when the bearings where done and perfomed perfectley. Confused!!???

[GreenV8S]

The glowing no charge warning light indicates that the switched ignition feed is at a different voltage to the alternator output. This could be because the alternator output is low, but I think you've ruled that out. It could also be because the switched ignition output is low, and that's more likely to be the problem I think. Check the switched ignition voltage, you probably have a drop somewhere. The multi-plug that connects the ignition switch to the main loom would be the first place to check.

[spend]

Mine always glows a little. After much testing ( I have even installed a Voltmeter ) the LED will actually glow when it shouldnt, replacing with a modern LED fixes the problem. Farnell stock the black recessed LEDs.

I didnt even bother with the thin black earth, tracing it I found it went nowhere! on my car.

The suppressor bolts to any of the alt case studs.

Dave

[ouiseyg]

Thanks for your input. I have investigated the main ignition block but did not find anything suspect but must admit have not tried a meter across it yet. I am going to try another earth of tne alternator bracket just in case the TVR bad earth curse has hit. As fot that black wire I've tried it on both positions with no differing effect. Anyway its winter and the tellys crap so what else would we be doing!!

[GreenV8S]

ouiseyg said:

I am going to try another earth of tne alternator bracket just in case the TVR bad earth curse has hit.

Presumably you'll measure and test this before you install it properly.

[Nick P]

I've just had an alternator problem sorted out on my service.

The 'fail' light was constantly on, but the battery was charging....it turns out the numpty who replaced the alternator wired it up wrong. It was something like the earth was onto the body of the alternator when it should have been to chassis.