quick question about the dynamo

Post by **Lukey** » Tue Nov 18, 2008 8:00 am

Drove the car home a few days ago was fine, parked it up started it this morning and I've got an ignition light. Defo a charging problem (as apposed to a mischievous ignition light) as the light gets stronger as you rev the engine and the wind screen wipers hardly work.

Would the brushes go like this? I'm more inclined to think the loom visibly checked it, I don't have a multi meter to go poking around. Could I test the dynamo with a test light off one of the terminals? Thanks again in advance guys n gals.

I wouldn't normally clog up the board and post silly little things like this but I'm so snowed under, I just don't have time to re-brush the dynamo if it's not going to work!

Post by **PSL184** » Tue Nov 18, 2008 8:06 am

First and obvious checks...
1 - Fan belt attached?
2 - Regulator contacts not stuck together?

If above OK then go for brushes. They can stick so they might just need pressing in a bit but if you know that they haven't been changed for a while then it won't hurt to do them.

ps. Just get a cheepo multimeter from Maplins etc for about £10.

Post by **Lukey** » Tue Nov 18, 2008 8:40 am

Yup both good, i think, non of the contacts in the reg are touching. I already have spare brushes to hand, just no time. I vowed never to buy a cheap multimeter again, kept on buying those cheap yellow ones I even had the ball bearing from the rotary switch fly out on my last one! The irony is not lost on me.

Post by **bmcecosse** » Tue Nov 18, 2008 12:46 pm

Just try tapping the dynamo with a hammer shaft - could be the brushes are at end of life and have 'stuck' slightly in the holders. If it does work - still change the brushes asap.

Post by **Lukey** » Fri Nov 21, 2008 8:56 am

The brushes were fine. About to go in to town to get some paraffin to de-grease the armature end which is filthy, should the armature shaft have loads of play when the communicator end is off?

Post by **Lukey** » Fri Nov 21, 2008 12:49 pm

Re-Brushed, works lovlie now.

Post by **rayofleamington** » Fri Nov 21, 2008 1:05 pm

vowed never to buy a cheap multimeter again, kept on buying those cheap yellow ones I even had the ball bearing from the rotary switch fly out on my last one! The irony is not lost on me.

same here - also had a PCB track burn out when measuring a few amps (on the 10A line) - the PCB track wasn't capable to take a few amps - i soldered a wire between the positions instead

Post by **bmcecosse** » Fri Nov 21, 2008 2:00 pm

If the brushes were fine - and now it works with new brushes - they obviously weren't fine - or were seriously jammed in the holders. Anyway - good to here it's working now ok! You've obviously realised that when the commutator end is off - the armature has no support and so is bound to have play in the front bush. A drop of oil on these bushes is ok - but no more than that.