<VV> re: light gremlins

[JVHRoberts at aol.com]

Well done! Remember, everyone, these cars don't have the electrical  
reliability of new cars (regardless how complex the new ones are!), nor are they  new! 
No new car would use a grounding strap. ALL grounds are in the harness,  
going to a lug SECURELY bonded to the body or frame somewhere. 
Alas, we don't have that, so....
 
I've connected ground wires to all my exterior lamp sockets over the years,  
and these gremlins have disappeared. If anything fails, it's just that item,  
like a bulb out, no backfeeding driving me nutz... <G>
 
John
 
In a message dated 7/4/2007 12:09:03 PM Eastern Daylight Time,  
djtcz at comcast.net writes:

as  others said, mysterious light behaviour is often a bad ground, forcing 
the  electricicals to  flow "backwards" thru other bulbs to use their  grounds.

It may be considered good practice to clean and tighten ground  straps every 
now and then, using somewhat of a shotgun approach.  
http://www.silverbulletcomicbooks.com/busted/images/060502/henry3.jpg

I  prefer to fix the ones that aren't working, or aren't working well.  It  
can even be argued that unless I check (measure voltage drop) my repair work  
(connection cleaning) , I can not be sure it is "perfect."

A "bad"  ground, fuse, connection, or even wire can be identified by 
measuring the  voltage  across it with device current flowing.  Perfect wires and  
connections have zero voltage "drop" when part of an energized circuit.   All 
real wires and connections have some resistance, but it should be no more  than a 
few % when handling full power.  Something like 0.3 volts for a 12  v  
circuit.
http://www.aa1car.com/library/voltage_drop_test.gif
http://www.prestolite.com/images_training/fig23-neg-cable-test.gif

http://www.prestolite.com/images_training/fig24-solenoid-voltage-drop.gif
http://www.excelauto.com/online/Tech.d/Image.d/StrVdt-2.gif
http://www.excelauto.com/online/Tech.d/Image.d/StrVdt-2.gif
http://www.tpub.com/content/neets/14188/img/14188_118_1.jpg

--
Dan  Timberlake







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