First, thanks to everyone who answered my post about my 2001 Honda
Civic with both headlights out.
Further investigation reveals that the high-beams work, but not the
low-beams. I replaced one bulb to see what happens, and it's the same
thing - the low-beams don't work but the high-beams do. The fuses for
the headlights look good, but as someone suggested, they could be bad
anyway. I don't have a multimeter to test them. Should I just replace
the fuses and see what happens?
Tegger - you mentioned a third, 100a fuse under the hood that protects
both sides of the headlight circuit. The biggest fuse that I can find
in the under-hood fuse box is an 80a fuse that protects the battery.
Is there one somewhere else?
You can check the fuse with a flashlight battery, bulb and a small piece
of wire. Just create the small circuit with the fuse inserted into the
circuit. If it lights, your fuse is good. If not, you've found the
Do you have DRL? If so check the low beam cut relay. If not possibly the
multifunction light switch. Spend a couple bucks on a millimeter and learn
how to trace the circuit. You can get a cheap millimeter for under five
bucks from Harbor Freight that will work for your purposes. If you plan on
doing your own service work you have to have one.
firstname.lastname@example.org wrote in news:28927a79-dca8-46f2-b553-048f3af825f5@
Do you have any aftermarket add-ons, like stereo, alarm, remote start,
If there are no intrusions into the electrical system, then your
combination switch is going bad. That's the stalk on the steering column
which controls the headlights.
The combo switch provides a common ground for the two headlamp relays
(the ground activates the relays), plus it provides a common ground path
for the high/low beam switch.
You need to buy a cheap multimeter (available at any auto parts place)
and some test wire and start tracing the circuits and actually testing
Try temporarily swapping in a 15A fuse from some other circuit, just to
be sure the fuses are OK.
Two simple tests you can perform if the fuses are good:
1) Ground terminal 7 of the combo switch connector (blu/red wire). Do
the low beams now come on? Then the on/off portion of the combo switch
2) Turn the headlight switch to low beams. Ground terminal 6 of the
combo switch connector (red/wht wire). Do the low beams come on now? If
so, then the high/low portion of the combo switch is bad.
It seems for test #1 you can tap the blu/red wire from the back of the
fuse block, so you don't have to mess with the steering column. But for
test #2 it looks like you need to either pull the column covers or
ground the red/white wire by backprobing it at the headlamp connector.
in the US,you can get a cheap DMM at Harbor Freight,usually under $5.
On sale,they sell for $3.
but test it first with a 1.5V alkaline cell;the 1st DMM I got from HF read
way high(>2.0V),had to exchange it for another that read OK.
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