Information Being lazy has been costly

Birchall

Birchall

Dick Chown Award 2016
My wife's A2 had a small issue this winter, the starter motor started to turn slower than usual.

The batter was the original one, so I bought a new one and it was better.

Then a month or so ago, after no indication of any problem, it failed to turn over.

Not a peep out of the starter motor.

I looked at the earth connection (externally) and it looked fine, almost like new.

So I bit the bullet and had a new starter motor fitted.

After 3 or 4 weeks the wife told me it wouldn't start the other day and I just thought it was a "blip", but then today it failed to turn over again.

So this time I decided that the only thing left was either a faulty starter switch (not a common fault) or the earth strap (a much more common fault, of course)

So I undid the bolt on the earth strap and after two turns it broke off!!!!

I could see that the face of the strap (the contact area) was dirty and grey and closer inspection of the bolt showed signs of arcing.

So I connected the earth strap to another bolt and "hey Presto" !!!!! All good!!!!

In the end a new battery and a new starter was probably not needed but no harm done and my wife now has a reliable car again.

But the Moral is, learn from the information on this forum and don't be lazy!!!!!!

My Bad !!!


Steve B
 
I had the same thing at the Birmingham social. It's coming up as an issue fairly regularly. I'd recommend that everyone considers having the earth connection behind the near side headlight removed and cleaned if it's not already been done. The new washer and copper grease applied to our A2 by Robin has transformed the lazy starting we experienced for years. It always started fine ( until it didn't! !)

Tell tale symptom is a lazy crank on the first turn or two of the starter.
 
I am open to being corrected but I believe after cleaning the mating surfaces it is best to re fit dry with no grease, copper or otherwise. Copper grease is not a good conductor but a great anti seizing agent. After tightening well, an application of vaseline or waterproof grease over the connection will prevent water ingress and reduce corrosion. I am sure the same applies to battery terminals.

Like many on the forum I had the sluggish turnover and externaly the the earth connection looked fine but on removal the washer was virtually erroded away by arching

Geoff
 
I think it's one of those cases where the theory is sound but 'practice' is better.
Totally agree that copper grease is not a good conductor but when the joint is clamped up I suspect the grease disperses and metal to metal contact is achieved over most of the surface area. The grease then has a negligible effect on the earth cable resistance but it does fill in all the 'micro pitting' to form a fairly good hermatically sealed interface.
This will prevent surface corrosion re-forming under the terminal for a much longer period than an external layer of waterproof grease.

Cheers Spike
 
Sound logic! It would be interesting to compare the 'meen time between failure' for joints made with the two approaches

Geoff
 
Sootywg said:
Sound logic! It would be interesting to compare the 'meen time between failure' for joints made with the two approaches

Geoff
Click to expand...
Yes, but you would hopefully have to wait ten years to obtain such data.
Either method applied properly should cure the problem for many years.
Steve B
 
Good lesson and advice, Steve. :)

This is something I've done recently too, as I've found my TDI has always been a little slower cranking than other TDI's in the family. There was no evidence of a problem at the connection in my case, but it's a good thing to check none the less. For the sake of 15 - 20 minutes work, I'd certainly recommend checking it and cleaning it up.

To add to the above about the grease, I don't put grease between mating surfaces as it's not a standard practice with my job, but I can't see conductive grease causing a problem. I put multipurpose grease over the joint afterwards to give a degree of corrosion protection, however. Either method will be fine. :cool:

Matt.
 
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