[DeTomaso] Dim Headlight

MikeLDrew at aol.com MikeLDrew at aol.com
Wed Feb 10 21:59:29 EST 2010


In a message dated 2/10/10 6:43:45 PM, jefude at bellsouth.net writes:


> #4134 (PreL) has a dim high & low beam on the right (passenger) side. I 
> have been advised that this is probably due to a poor ground.  Can anyone 
> tell where the grounding point is for the headlight circuits?  Or am I better 
> off just running a new ground?
> 

The ground for the front lights is on the main stud under the dash.   That 
stud is impossible to find until you recognize that it is actually a 
two-ended stud; the other end is the where the battery ground cable attaches.   
There are numerous ground wires from all around the front half of the car that 
converge on this single stud, which is virtually impossible to reach because 
it's blocked by the heater box etc.

Chances are, your problems are not caused back there, but rather at the 
pigtail connection up front.   The headlights have a fairly short harness 
(perhaps a foot long) that then plugs into the main harness; lots of opportunity 
for corrosion etc. at either that connection, or where the harness plugs 
into the back of the headlights.   Time spent separating those connections 
(four in total, two on each side) and thoroughly cleaning them out, is time 
well-spent indeed.

Some advocate unplugging the ground wire from the connector and grounding 
it locally to the body, instead of running the ground all the way back around 
the car to the post in the cabin.   Perhaps that's something to consider if 
simply cleaning the existing connections doesn't work.

Mike



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