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
>