12 replies to this topic

[HoneyClubman]

Hey folks,

Finally got our 1972 clubman back onto the road after 18 years, but I’ve got one issue left to solve. The alternator isn’t providing any charge to the battery!

Alternator light is on the dash, I’ve cleaned up all the earth points and connections, fan belt is new and tensioned correctly, I’ve tried with the original alternator and 2 replacements bought from minispares… all do the same thing.

Question: if the alt plug is disconnected, I can see 12v thru the igniter wire when ground to engine and ignition on. When the igniter wire is connected to the (all 3 of!) alternator, it is only showing 1.5v…. Is this normal?

I’m guessing not as I’d expect that 12v to be required to turn on the charging circuit?

Any thoughts?

Edited by HoneyClubman, 22 May 2022 - 07:16 PM.

[Spider]

What type of Alternator did it have and what have you replaced it with?

Your initial Tests sound perfectly normal, I can't see an issue there.

 

[HoneyClubman]

45 Amp alt - GXE2211 from minispares.

Unless all 3 alternators have the same fault, I’m guessing I must have a wire/earth issue somewhere, but I’m really struggling to find one 🙈

[Spider]

The Brown / Yellow Wire that runs to the Alternator, disconnect it and turn the key ON, the Lamp should be out.

If you put that wire to Earth, the Lamp should come on. From your description so far, this sounds OK, but maybe check this way all the same.

The big Brown Wire, check that has 12V on it (key can be off), don't short that to Earth though. Follow it back to the Solenoid, perhaps take the wires off here and clean them up.

Check the Earth Strap on the Battery as well, though, if you are able to start it OK, I'd say all the Earths are OK.

I can't see 3 dead Alternators, especially given 2 are new.

[nicklouse]

You have not changed the lamp to LED have you? 

[HoneyClubman]

Yes the light goes out when the wire is disconnected. I haven’t checked that it comes on when connected to earth - I’ll check that tmrw.
The earth strap and solenoid have both been replaced as well! New fuse box as well… still the original positive lead though…

[HoneyClubman]

No, the lamp is still a standard bulb, hasn’t been changed to led.
I have also dismantled the clocks, and made sure the bulb and connectors behind the clocks are all clean/good…

[Steam]

Firstly just so you are not confused the lamp wire Br/yel needs to have 12 volts for the light to be OUT.
Secondly, are the new alternators identical to the original. Thee reason I ask is 72 clubman here had an alt with remote regulator.

[Ethel]

It doesn't earth as such, depending on what you meant by earth points. As above, there should be +ve voltage on both sides of the bulb, hence the bulb holder should be insulated (plastic). Your meter will measure the difference in potential so 1.5v can be right if one probe is at 12v & the other at 13.5, depends where you stuck 'em.

 

If you want to know if it's charging, put your meter across the battery terminals. Turn the engine on & hold it at around 2000rpm and it should increase the voltage: around 14v is typical. You could also turn on your headlights, it shouldn't drop the voltage appreciably.

[HoneyClubman]

It's solved!!

 

Had a pal review my thoughts last night - on showing him a picture of the solenoid wiring, he realised that the alternator was connected to the starter post, not the battery post... 

 

In my defence, it's been that way since 2012 (when it was last tried to get her on the road) so I just surmised that I had kept all the connections in the same position as the last time she ran properly. 

 

Switched those over now and the battery is charging correctly again. 

 

Thanks all who replied - much appreciated. 

 

Just shows you, you're always better to get a 2nd pair of eyes on things...  

[cal844]

Good to hear its repaired, well done!

Edited by cal844, 23 May 2022 - 11:57 AM.

[Steam]

You are neither the first nor the last to do this.
Great news that you fixed it.

[HoneyClubman]

You are neither the first nor the last to do this.
Great news that you fixed it.

 

Very glad to hear it!! 

 

Just annoyed with myself that I took pictures of how it was all wired up (incorrectly) to make sure I kept the wires in that order this time around....    Anyway, just the fuel tank float to sort now and she's perfect.