APA, I appreciate your explanation, and it is a correct one when using an ohmmeter. However you can also detect a bad ground using the voltmeter function as well. Since many people don't know that you shouldn't use an Ohmmeter on an energized electrical system and risk destroying the meter, I like to tell people to use the voltmeter function because it's safer to the user and the test equipment.

Using your example above, if I put my voltmeter leads on the shell of light socket and the ground point, I will read 12--14 volts. If it reads 8 volts, then I have a voltage drop and most likely a bad ground.

 

well i thing im going to try to just run a tep. ground and if that dosent work its going in the shop.

 

If you have a good ground there will be no voltage shown between the socket and ground since the internal resistance of the voltmeter portion of a multimeter or straight voltmeter offers high resistance to current flow and the current will take the path of least resistance to ground. I will grant that it also provides a parallel path for current flow, and some current will flow through it also as a shunt, which is the device used with ammeters to measure current flow on high amperage circuits that would blow ammeters if connected in series without them. That is a whole other animal though.
If there is a reading with the voltmeter there is a bad ground in which the current would have to flow through the meter rather than the ground to complete the circuit.
Today, all digital meters are protected against incorrect function applications,but the e cheaper analog multimeters are normally not so protected, so I can see your point in a novice screwing up a meter.
I've been in the electrical and automotive field for 51 years now and have seen a lot of DIY stuff that would fill a few books. Nothing is impossible to the untrained.

 

so u want to come up to se pa and fix it!!!! and there no reason to write a hole page cause my fat lazy *** in not reading all of that.

 

Transfer of knowledge only, yours to accept or reject as you wish. Sorry if you got offended .

 

dam dam shame u wont come on up so im a simple form what would you like me to try 1st if u want so pic. and if that dosent work 2nd thing i can do. 3rd thing i can do. and the 4rd thing is going to call the shop and put her in there hands for a day. question what dose the cable connect to anyway and whats it called and whats it connected to and the location of that connection. i tryed calling a junk yard and didnt get anywhere at all.

 

APA, my bad. I got it backward on the voltmeter. You are correct, 0V for a good ground. However, I will still rely on the voltmeter when working on/diagnosing live systems. It was just drilled into my head years ago by old school instructors to always set to the correct scale and never use the Ohmmeter without disconnecting the source and properly isolating your circuit for the measurement. We used analog d'arsenval movement meters (like Simpsonmeters) and they got mad as hell if you smoked one!

My apologies for hijacking the thread.

 

I will send you a pdf file of where this particular ground is located. You can check it out on your own and see if it is the problem. If not, any good automotive electrical tech will be able to solve your problem.

 

1- Remove bulb, check that contact points on bulb and in socket are clean and bright, re-install bulb if clean/bright, if not clean and re-install/test.
2- Connect test ground wire from good point to ground contact of bulb socket, turn lights on & test. If good make a permanent new connection to ground point at socket.
3- If not good run test line from low beam socket on l/s to r/s & test again. If good run new line from l/s to r/s permanently. Do same test/repair for both high and low beams.
My bet is still on a bad ground.
Hope this was short enough for you.

 

thank you much better thanks for putting up with my bull. What is this "l/s to r/s" you speaking about?