Assitance needed ... it won't take long.

[Bakdraft007]

Hi,

I am looking for some assistance relating to AC harmonics on the DC charging circuits for both the Mk 1 (with original AC11 alternator with 16RA and 4TR control) and Mk2 Stags.

If you could I simply need to know what harmonics are seen on the DC charging circuit with the engine running at about 1,800 rpm. To measure this simply connect a digital voltmeter across the battery with the engine running at 1,800rpm. Please could you supply:

1. The DC voltage measured
2. The AC voltage measured in millivolts - maybe between 50mv and 300mv
3. The type of alternator, mk1 mk2 etx and if mk1 control circuitry

I ask this as I am putting together a comprehensive Manual / troubleshooting guide for the charging circuits. Of course I can measure my own, but that is a sample of only one .

Any help you could give me would be appreciated.

Thanks

Dave

[mole42]

DC 14.58
AC 14mV
Mk2 alternator, probably 90A high-power

[Bakdraft007]

Thanks Richard, that's really helpful...

Anybody else can help with this I am just looking for 5 or 6 people to make some readings?

Also has anybody got an old MK1 alternator that has failed, I am looking for a Diode pack off the back to repair mine

Thanks

Dave

[NeilR]

For what it's worth.

Checked mine today before venturing out.
From cold
14.25 Vdc
55ish mV AC ripple, dropped to
30ish mv after a couple of minutes, still charging after the startup, would probably reduce further in time.
Using an A127 55 a/h alternator.

[Bakdraft007]

For what it's worth.

Checked mine today before venturing out.
From cold
14.25 Vdc
55ish mV AC ripple, dropped to
30ish mv after a couple of minutes, still charging after the startup, would probably reduce further in time.
Using an A127 55 a/h alternator.

Thanks Neil, I really appreciate your help. Part of my asking is my MK1 (AC11) has 300mv of AC ripple..and so seeing what others have is very helpful. I really need another Mk1 with an AC11 to help me understand what is normal and what is not. I have completely disassembled the alternator and tested each of the 6 diodes and they all check out perfectly, so I a trying to decide if there is an issues or not.

Hence I need as much input as possible.

Dave

[wilf]

14.18 V DC
ripple unmeasurable (maybe my meter is nbg)
mk11, standard 17acr alternator (well a chinese copy of the Lucas item).