Dynamo problem?

Post any technical questions or queries here.
Post Reply
User avatar
coopertim
1275 Cooper S
Posts: 1895
Joined: Thu Jun 24, 2010 8:45 pm
Location: In the garage spending far more time and money than my wife agreed to! Lincolnshire UK
Has thanked: 28 times
Been thanked: 8 times
Contact:

Dynamo problem?

Post by coopertim »

Morning all, how do I tell if the dynamo has had it? Whilst the car was in for MOT the workshop charged the battery and the car started on the button no problem. The last few times starting though it has seemed as if the starter motor has stuck and won't engage but the car starts by bumping straight away. I took the starter motor off yesterday and lubricated it but the problem is still there with the power running down. I've took it on a fairly long run but it makes no difference - switch off and it refuses to turn over.

Dynamo had it?

Cheers. Tim
coop12g295
998 Cooper
Posts: 693
Joined: Thu Jun 24, 2010 4:31 pm
Location: Portsmouth Hants

Re: Dynamo problem?

Post by coop12g295 »

My first check with it running,put voltmeter on battery and you want to see approx. 13,5 volts
Daz1968
1275 Cooper S
Posts: 1440
Joined: Sat Dec 27, 2014 1:41 pm
Location: Oldbury west midlands

Re: Dynamo problem?

Post by Daz1968 »

Easy test is to remove it from car apply earth to body and connect live to both terminals, should spin up as a motor if it does this problem is likely with control box. There is a guide on this site somewhere with test procedures
User avatar
Simon776
1275 Cooper S
Posts: 1181
Joined: Thu Jun 24, 2010 6:08 pm
Location: Shakspere's county

Re: Dynamo problem?

Post by Simon776 »

If the ignition light goes out that usually indicates all is well with dynamo. Have you checked that the battery isn't being over charged?

I'd also check the engine earth strap and stater solenoid.
The power of accurate observation is commonly called cynicism by those who do not possess it.
User avatar
coopertim
1275 Cooper S
Posts: 1895
Joined: Thu Jun 24, 2010 8:45 pm
Location: In the garage spending far more time and money than my wife agreed to! Lincolnshire UK
Has thanked: 28 times
Been thanked: 8 times
Contact:

Re: Dynamo problem?

Post by coopertim »

Many thanks for the replies!

Simon, the ignition light stays on even when revved so i would say that theres a good chance the dynamo needs attention!


Tim
Daz1968
1275 Cooper S
Posts: 1440
Joined: Sat Dec 27, 2014 1:41 pm
Location: Oldbury west midlands

Re: Dynamo problem?

Post by Daz1968 »

My ignition light stayed on, dynamo was fine it was just the points in regulator box needed a good clean. There are a few videos on YouTube from moss Europe that explain how the system works but all you need to test it is a basic voltmeter
User avatar
LarryLebel
998 Cooper
Posts: 547
Joined: Sat Feb 15, 2014 12:02 am
Location: North Vancouver BC

Re: Dynamo problem?

Post by LarryLebel »

Could be a bad battery. Have it load tested.
User avatar
Andrew1967
1275 Cooper S
Posts: 7911
Joined: Thu Jun 24, 2010 6:35 pm
Location: Usually in my garage on the east coast of Norfolk, UK
Been thanked: 5 times

Re: Dynamo problem?

Post by Andrew1967 »

More likely to be the regulator than the dynamo, as mentioned previously.

But...never say never !
InimiaD
1275 Cooper S
Posts: 1526
Joined: Thu Jul 01, 2010 11:20 pm
Location: West of Offas Dyke.

Re: Dynamo problem?

Post by InimiaD »

Might be worth checking the springs holding the brushes (in the dynamo) are intact. I had the same thing happen to one of my old Minis and I found one of the springs had rusted through.
Post Reply