I have a 1997 Escort which uses #9007 low/high headlamp bulbs. Soon
(days/week) after the psgr side's low beam went out the other side went. The
high beams were unaffected. So I bought and changed bulbs on both sides.
Within a day or two the psgr side was out again and only the driver side
regular low beam worked. To be honest I didn't notice if both sides worked
for any short period of time when I first installed them because I didn't
realize I had to release the parking brake. Then I took the good low bulb
from working driver side and put in in the psgr side and it did work there.
And the dead bulb from the psgr side psgr did NOT work at the same time on
the driver side. So I then took the broken low bulb right out of the car and
drove 1/3 mile to the store to get another bulb. On the way I guess it was a
circuit breaker or some electronics that was clicking loudly like crazy
under the psgr dash (first and last I ever heard it). I installed the third
new 9007 on the driver side in the parking lot, and when I got home (2/3
mile total) that new bulb in the driver side was the only bulb working; the
psgr was blown again. It could have blown on the way to the store.
If both the 9007 bulbs did work when I bought and installed them, then that
could mean the car's electronics could be blowing the psgr side bulb, even
if I blew one 9007 driving with just a single. If however I bought a bad
bulb the first time, and then when I switched the good one over it blew
because I drove to store with just that one side installed, then maybe I yet
just have to buy another 9007 bulb and have both installed at same time.
AN ANSWER TO THIS ONE QUESTION COULD PROVIDE MY ENTIRE SOLUTION
OR IS IT:
Could it be a fuse or something else simple bad somewhere, or is there poss
a problem with the electronics? My best case is if there is no problem with
the electronics; no repairs/diagnostics.
Given the symptoms you describe, my first inclination would be to check
charging system... both at idle and at about 2000 rpm..... Overcharging is a
There... now arent you glad you didn't have to page down a bunch of times
to see my reply?
The headlights both are supplied with the same voltage and so the
operation of one doesn't affect the other. You might want to check the
voltage in the system. If voltage goes much over 13 volts when the
engine is running your voltage regulator must be bad.
Other than that, be sure your are using a good quality bulb of the right
type. Water inside a light can break the bulbs though that doesn't seem
to be your problem.
Then every car on the planet must have a bad regulator. Since the basic
chemistry of a lead-acid battery gives approximately 2.14 volts per cell,
a fully charged "12v" battery should read about 12.8 volts. A normal
alternator will put out around 14.5 volts when running.
Moses earns a Fail on that one. The battery in a car is charged as
a constant-voltage float charge, and the voltage output by the
alternator is varied with the temperature to match the weather.
The proper alternator output should be about 13.8 Volts at around
60F, and it rises to roughly 15.5 V at 120-ish Fahrenheit. The only
time over 13V is bad is when the engine has been off for a few minutes
- the static charge should be around 12.6V on an unloaded battery, but
can be higher from a surface charge if the engine was just shut off.
Now there IS a way that the headlights could be popping because of
the alternator - overvoltage from a bad battery or totally dirty
cables and connections. If the battery or the cable connections
(either positive or negative) go open, the alternator will keep
raising the voltage till it gets some feedback that it is high enough
- and without that feedback the output can easily go above 24 volts,
more than enough to pop light bulbs and cause other severe damage.
And if it's a dirty/loose lug in the stack on the positive post
adapter, part of the system could be staying at the proper voltage
because it sees the battery and not the alternator, and another line
can go high because it sees the alternator and not the battery...
--<< Bruce >>--
Well that clicking I mentioned was very loud and no one would ever drive
like that. If generally there is no likelihood the bulb would blow if
installed alone then maybe its electronics, but I'm telling you the car was
freakin out !
"clare at snyder dot ontario dot canada" wrote in message
If you touch the bulb glass with your fingers, it tends to shatter the bulb
just burn out a filament.
I would test the voltage at the battery. There's a good chance that the
on the alternator isn't doing a good job of regulating the output voltage
about 14-14.5 volts max if the battery is fully charged). If it doesn't show
while parked, set up a connection so that you can observe the voltage while
driving (or use a better quality OBD-II tester that shows system voltage).
The headlamps are on a circuit breaker, not a fuse. That's probably the
hear under the dash. I would check the wiring near the headlamp for shorts
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