Hi Scott, 

1/3 Volt is acceptable in a low current situation - but if it's in the ground connection for a starter motor or a radiator fan motor, that's too high... overheating looms.

Great point about star washers!

James
Ottawa, ON

> Date: Mon, 14 Sep 2015 11:55:20 -1000
> From: scottdaniel@TURBOVANS.COM
> Subject: Re: Intermittent hot start problem - check all connections!
> To: vanagon@GERRY.VANAGON.COM
> 
> Nice to read this James.
> 
> I'm sure you know this brilliant test/trick...
> to measure the 'current drop' across a ground connection.
> 
> to do this ..one energizes the circuit,
> put meter of DC voltage scale,  leads on both sides of the ground..like
> on body and wire ..
> the read milivolts ..
> ideally this part of the circuit 'drops' or uses zero voltage of this 12
> volts DC circuit .
> in practice it will be a few millivolts, that you can measure.
> I think 300 milivolts ( roughly 1/3 of a volt ) is acceptible..above
> that , not good.
> 
> also ..great, great trick for grounds with screw-eyes on the wires .
> Find a 'multi-star' pointy washer ..put it between screw eye and body ...
> the points dig in ...excellent ground that way.
> I have noticed this on Renault cars starting in 1970 at the tail lights..
> On  an 85 mercedes I own ..they have huge ( 1/2 inch across almost ..and
> on a small screw too ..like 6 mm screw or stud  ) star washers on the
> front turn signal housings.
> 
> but yeah...Connections ..it's very often connections.
> I swear, counting all vehicles and electronic and house devices...I work
> on and fix 'connections' many Hours a week, every week.   No
> exaggeration either.
> 
> scott
> 
> On 9/14/2015 11:17 AM, James wrote:
> > oh..fwiw ..in all things car performance related ..I find poor
> >>>> connections being the real cause as much as a good 60 to 70 % of the
> >>>> time...and it being 'a component' that's bad the rest of the time.
> >>>> ...i.e. it's not 'always'  A Component at all.
> > As someone who teaches electronics for a living, and has spent all of his driving lifetime dealing with "old cars" (our family fleet averages 18 years old!), I want to strongly echo this observation.  Very strongly.  Very, very strongly!
> >
> > Always check every electrical connection in a circuit.  Never assume that 30 year old little plastic connector and it's aluminum or brass strips is still 'all right'.  I had a Rabbit once that had a completely dead ignition system, due to a single bad crimp in a single relatively inaccessible plastic connector.... it was hard to reach, but surely that little wire was find, right???
> >
> > James
> > Ottawa, ON
> >