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Subject:Re: Need Help with Headlights
From:David Beierl
Date:Wed, 4 Jan 2012 10:17:25 -0500

At 09:44 AM 1/4/2012, Pat Patterson wrote:
>When I have my low beams on I have all four lights dimly lit.  When  High
>beams are selected I have 4 really bright lights.

Something funny with your wiring.  On low beam you're running the two
(high/low) in series instead of just low to ground.   This happens in
taillights sometimes with a bad ground where the running light seems
fairly ok because it's grounding through the stoplight filament, but
when you put on the brakes everything goes out because now you're
powering both filaments.   I'm having trouble visualizing how that
would go with proper operation on high beams, but a voltmeter will
tell you what's going on.

On low beam, which filament is lighting up in the main light?  High,
low, both?  I think your problem is probably easier than Robert's,
but you'll still have to trace out the voltages to see what's happening.

You've got twelve volts worth of voltage difference available in the
circuit.  You need almost all of it to show up across the terminals
of [each] light that you're powering, ~+12 on one side and ~0 on the
other.  Same advice as I gave Robert.  Hope it's warmer where you are.

Yours,
David