31 replies to this topic

[PetePinnington]

Ok did that alternator test and It does seem to be the alternator. I'm going to borrow my brothers alternator tonight and give that a try just to be 100% sure.

[PetePinnington]

Well, last night I borrowed my brothers alternator which I knew worked. Still wasn't working though. Turns out it was from where I wired up my acewell speedo! Didn't think anything of it at first as there are earth wires coming from the acewell. But I guess the brown and yellow wire wasn't earthed from these wires. Connected it back up to my old two clock speedo which is still in the car (for the temp gauge as I haven't got round to sorting that out yet) and bobs your uncle. All charging now thanks for all your help! Mucho aprecciated :)

[Dan]

The brown/yellow isn't meant to be earthed!

[PetePinnington]

Oh is it not? I don't understand why it works in the old speedo then? All that's wired to the back off that is the panel lights, temp gauge, an earth, and now the ignition light

[KernowCooper]

The clue here may have been the old dash ignition light was feeding the exciter circuit through the bulb to the alternator, no 12v ignition light = no charge same as if the bulb blows

[Dan]

I think you need to read one of Kernow's excellent threads about how the no charge warning works.

[KernowCooper]

Its here to help pinpoint the fault were discussing http://www.theminifo...g-how-it-works/

[PetePinnington]

Ahh ok I think I have it, there is a white wire in the back which I had forgotten about. So for the battery to charge, the white ignition wire needs to be connected to the bulb which is then connected to the brown and yellow? My acewell speedo only has one wire coming out for the warning bulb. How do I go about wiring this up or would the only option be to source an external bulb and mount it somewhere else on the dash?

[PetePinnington]

And that is an excellent thread! Wish I had seen it before!

[KernowCooper]

As long as the exciter wire is connnected up and fed in he same manner as in the article then yes, some kit cars use a seperate charge light.

[PetePinnington]

Okie dokie, I can't see a way of wiring it up to the acewell so I'll just use a seperate light. I've got a few of these kicking around, will it be ok to use on them?

[Dan]

Which Acewell is it?

[PetePinnington]

It's the 3973

[Dan]

How did you wire it? Brown/yellow directly to the green pin in the multi plug for the lamp would be the right way, but the lamp is an LED which is the real problem. The circuit needs to flow around 2.2 watts straight off the ignition switched supply. Even if the lamps are replaceable you won't know if it's up to the job of carrying enough current internally or if it's wired right. You could make it work but it would mean surgery to the unit. Alternatively you could use a resistor and a diode protected relay. If the resistor and relay coil together had the right resistance to make the alternator work, they would be doing the functional job of the warning lamp in the circuit. The relay would then be driving the warning lamp in the cluster. It would be very much an on/off switch though and you wouldn't get a warning of minor under voltages as you do with the lamp.

[Captain Mainwaring]

As long as the exciter wire is connnected up and fed in he same manner as in the article then yes, some kit cars use a seperate charge light.

 

As usual uncle Kernow provides top info. Worth reading the article though as the alternator fitted is capable of both machine and battery sensing.