Headlight Issue--Bad Wiring...?
Daniel Stern Lighting
> I have a 2000 Nissan Quest Van. The right Headlight seems to be on the
> blink. The blub is 100% ok, since it works on the left side . When I
> take a Voltmeter this is what I see: (left middle right pins)
>
>
> left <---> right pin NO Volts (on the working side, I get 12 volts)
> middle<---> right pin 12 volt
>
>
> so, what is the normal way is fixing this wiring issue. The wires are
> all bundled together...
Your 2000 Quest, if it is a North American model, uses 9007 headlamp
bulbs. As you can see from the "9004 vs. 9007" document located here:
http://www.candlepowerinc.com/?url=17 , the pinout on your headlamp bulbs,
when held "right side up", is thus:
Left pin: High beam
Center pin: Common (labelled "ground" in that document)
Right pin: Low beam
Your Mazda, like most Japanese-design vehicles, uses a ground-switched
headlamp circuit. That is, the center wire is hot whenever the headlamp
switch is on, and a path to ground is completed for either the "low beam"
or the "high beam" terminal depending on the position of the beam selector
switch. The only operational mode in which this is NOT the case is on some
vehicles with Daytime Running Lamps. Is your van a Canadian-market model?
If so, be aware that there are many different ways of reducing the
intensity of the headlamps for use as Daytime Running Lamps. Some vehicles
use an external resistive or pulswidth-modulated DRL module, but some put
the high beam filaments in series with one another, and some put the highs
AND lows in series with one another. Just something to be aware of.
You say you found:
> left <---> right pin NO Volts (on the working side, I get 12 volts)
Sounds like a fault exists on the "working" side. You should not have 12V
between the left and right pin, this would put the low and high beam
filaments in series on that side. See comments above.
> middle<---> right pin 12 volt
This is correct for low beam operation.
DS
magellan
thx for the quick feedback DS...
What I guess I need to know, is this something that is repairable by
the avg owner, or something I need to take it to the shop. Other than
the delearship, can most service places do this repair, or do I need
to take it to a shop dealing with auto-eletrical issues.
thx
magellan
Daniel Stern Lighting
> What I guess I need to know, is this something that is repairable by the
> avg owner, or something I need to take it to the shop. Other than the
> delearship, can most service places do this repair, or do I need to take
> it to a shop dealing with auto-eletrical issues.
Even the most complex factory headlamp circuit is fairly simple. Any
*competent* general auto mechanic ought to be able, using the wiring
diagrams, to figure out where the problem is and fix it. So, if you have a
trusted general-repairs shop, go ahead and try them for it. If not and
you're shopping from cold, you may do well to focus in on auto electrical
repair places.
DS