97 accord - low beam head lights don't work

They just stopped working. Bulbs are not blown, fuse under hood is good,
even changed out with a new one to be sure. Bright lights work, brake
lights work, everything is working fine. What do I need to check now?

Help
G

 

They just stopped working. Bulbs are not blown, fuse under hood is good,

Both sides are out, right? The following assumes that this is indeed true.

I don't have the schematic for your car, but I'm pretty sure low beam does
not go through a relay on an accord (unless someone could check that). It
most likely goes directly through the headlight switch on your steering
column.

You will need a multimeter -- something that can measure DC voltage and
resistance. Sears has a cheap one ($12) that will work just fine.
Check to make sure you get 12V on either left or right low beam fuse by
taking one of them out. Do whatever you need to do to turn the headlight on
under normal circumstances.You should see 12V on one leg between one of
these fuse connections and ground.
If you don't, most likely your light switch (the one on your steering
column) is bad or the wire from that switch to the fuse holders (both left
and right) is bad.

If you do see 12V, turn lights back off. Set the multimeter to ohms and
check between the other leg of the fuse you were just on and ground
(battery - will do fine). You should see continuity there (something in the
order of ohms -- not KOhms or more)
If you don't, you have a bad ground connection near the headlight. This case
is unlikely, because your highbeams work.

If I had to put money on this, I think your headlight switch is bad.

Hope this is useful.
Remco

 

isnt there a separate fuse for the headlights under the dash as well? or no?

 

isnt there a separate fuse for the headlights under the dash as well? or
no?

Yup -- but that one is common to all lights (high and low beams). Since the
high beams are working, that fuse must be ok.
The other four fuses (left/right high/low) are in series with that one, I
think -- don't have his accord schematic, but that is the way it looks on
the one I have.

 

In other words, I doubt if it is a fuse: Besides him having changed them
already, what are the chances that both fuses for both left and right low
beam blew at the same time.

 

Looking at a generic wiring diagram for the '94 - '97 generation, it
seems both the low beams and the high beams have relays, both located in
the under-hood fuse box.

To the OP: Are you sure your high beams are still working? According to
the wiring diagram, the high beam relay is connected in series with the
low beam relay, so if the low beam relay should fail, you would loose
both low and high beams (including the blue high beam indicator light in
the instrument panel).

I don't find any path in the wiring diagram that is shared between left
and right low beam without also being shared with the high beams.

 

both are out, correct and the high beam works the indicator light is on in
the dash and they are working. Will let you know the outcome later today.
I bet it's the switch at the steering column too.
thanks for the advise everyone

 

It may not seem to make sense, but I would suggest changing _one_ bulb
before taking the column apart. While it is unlikely for both bulbs
to fail at the same time, it is not impossible, especially if you
have a failing voltage regulator. A voltage spike could cause the
bulbs to fail. Bulbs are cheap and easy to replace.

Dan

(This account is not used for email.)

 

Thanks, Randolph, for checking that. While I haven't worked on an
Accord it a bit, I really should get an updated manual one day.. This
fact does change the diagnostics some.

On the common path, there must be a different non-shared high/low beam
path, because if they were all the same all lights would go on: one
would not have low or high beams.
On an older car I had, the low and high beams would turn on when you
pull back on the high beam switch - that's why they wired the relay in
series. It most likely isn't really "series", but they wired it into an
OR situation: switch low beams on OR pull back on the high beam flasher
turns on low beams.

See if high and low beam relays are the same type.
If so, try to swap them and see if the problem moves: if now your low
beams work and yet your high beams do not, clearly the relay must be
bad.

If the relays are different, see if you see a change from 0V to 12V on
one leg of the low beam relay when you turn the lights on. You may need
to probe around. Onother leg probably always has12V on it (depending on
how they switched it).

Report back here with your findings -- now that we have someone that
has an updated schematic, you should be able to solve it.

 

On my Rover 216GSi, there is a 'dim dip' resistor which only affects
the Dip side of the lighting.

 

The lights are wired so that you can not have the high beams on without
the low beams on also. Clearly you can have the low beams on by
themselves.

Specifically, the head light relay supplies current to both the high
beam and the low beam bulbs. The low beams are always grounded, the high
beams are grounded through a relay controlled by the dimmer switch. See
http://www.geocities.com/ng_randolph/Accord/94-97_accord_lights.pdf

So, if the high beams are working, a relay failure can not be the cause
of low beams not working. What is left is broken wires, missing grounds
or a failed head light switch.

To the OP: You said the high beams *are* working; When the high beams
are on, are the low beams on as well? If so, the switch is most likely
the problem. If not, my guess is that both bulbs failed.

 

To the OP: You said the high beams *are* working; When the high beams

I stand totally corrected and need coffee now to wash that crow and shoe
down with
This schematic is quite different from the one I have, but mine is much
older.

Agreed also on the relays -- if the high beams work by themselves, low beams
should be on as well. It could still be the column switch.

Measure the voltage on the light's connector. Weird if both are blown at the
exact same time, but I guess they developed Mean Time Between Failure to an
exact science so they can count on selling lamps from time to time
That ground connector from the low beam (black) could be something they put
on a common connection somewhere so I'd trace that, should you not see 12V
on the low beam connector.

 

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The hi- cut relay can get welded over time (what's your mileage??) At
least we're talking about an American version. Throw in DRL, and the
troubleshooting gets even wierder. My '95 Odyssey welded the relay and
it was solved the second we changed it, HOWEVER, the lugs in the
headlight lamp connectors can get loose from torqueing them on and off
so many times, so keep an eye on that too. The hi-cut relay is above the
brake pedal, attached to the firewall, in a '95 Ody. Accord is
probably similar. The relay will probably be mounted in a rubber (sound)
isolator.

'Curly'