headlight problem

Asked by Dec 26, 2012 at 01:24 AM about the 1990 Mercury Grand Marquis 4 Dr LS Sedan

Question type: Maintenance & Repair

1990 (mfg date 11/89) Mercury Grand Marquis, 5L, MFI, loaded

Cut to the chase:  what is the correct multi-switch (dimmer) for this vehicle?  O-Reilly's says (and gave me) a BWD #S3217.  I think it is wrong.  Now the story:

About a year ago the brights began going out (all lights out).  Switching to dims brought them back.  Thinking it was the multi-switch, I bought another.  A previous vehicle ('79 Toro) had a similar problem that turned out to be the multi-switch partially melting.  As it was near the end of winter and I had little time, I put the switch in the trunk and drove on dims.  Friday, on the way home for Christmas weekend (of course) the lights started going off entirely.  Fiddling with multi-switch got me home.  I could hear a clicking behind the dash as they turned on and off.  I have since read that the problem may be the headlight switch (WAH).  The wah is because I replaced the multi-switch and disassembled the old one to diagnose problem.  All I found was some carbon blacking on the contacts.  This switch is built much better than the Toro switch.  I see no evidence of plastic melting.

Anyway, problem now is that I now have daytime running lights (didn't before), and the battery drains overnight.  Disconnecting the battery and putting an ammeter in series, I get a 1 amp drain with doors shut, no key in ignition, trunk shut, and hood bulb unplugged.  Oh yeah, when I say I have daytime running lights, it doesn't matter whether the headlight switch is pushed in or pulled out (yes, old style) the lights come on as soon as the key is turned and will not turn off (key out, waited over a minute) until the battery is disconnected (stay off after battery re-connected until key turned on).  The only thing I have done during this project has been to remove the old switch and replace it with the new.

I suspect I was given the wrong switch (ya think).  I am thinking about getting a battery cutout switch tomorrow so I can drive to work (30 miles each way) and not have battery drain down while at work, but am concerned that the incorrect switch may cause other problems.


Really, any assistance will be greatly appreciated.


1 Answer


Make sure that they gave you the switch with the headlight delay. There are two switches. One for cars with headlight delay, one without. It seems like you got the one without, that's why the lights are not going off. Go back to reily's and have them double check it for you. Most of these autoparts stores nowadays have kids working there that don't know didly-squat about cars, especially one that's probably as old or older than they are. Kenny/MrBlueOval

Your Answer

Add photo

Related Questions

  • what is the problem when headlights do not come on 4 answers

    having problem with headlights not coming on. Is there a known problem?

    2005 Mercury Grand Marquis LSE


    Maintenance & Repair

  • intermittent headlights 7 answers

    Headlights just started to go out then come back on, parking lights not affected. Where should I start to track this problem down? bugman

    2004 Mercury Grand Marquis GS


    Maintenance & Repair

  • I have a 1987 Mercury Grand Marquis LS. Headlights won't turn on. 1 answer

    Replaced headlight switch{not the problem] If you pull back on dimmer switch the lights will lite but then shut off when it is released. Where is the relay for the headlights? Should I replace dimmer ...

    1987 Mercury Grand Marquis


    Maintenance & Repair

  • AI Cardone refurbished LCM does not fix the headlights off problem - what next. 1 answer

    This is the classic 'All lights work except headlights - high beams only with flash to pass'. Thought I'd be home "free" with the replacement LCM. Are there any other components, relays, switches et...

    1998 Mercury Grand Marquis 4 Dr LS Sedan


    Maintenance & Repair

  • Headlight? 1 answer

    how do i replace the headlight in my charger.. my drivers side headlight doesn't work and i wanted to try changing the bulb before taking it to find out if there is a wiring problem

    2006 Dodge Charger SRT8


    Maintenance & Repair

Search Mercury Grand Marquis Questions

Mercury Grand Marquis Experts

#1 Tracy Hooks
Tracy Hooks
Reputation 5,150
#2 kbro
Reputation 2,040
#3 Js08016
Reputation 1,620
View All

Related Models For Sale

Used Ford Crown Victoria
10 Great Deals out of 1,210 listings starting at $1,700
Used Lincoln Town Car
30 Great Deals out of 2,075 listings starting at $1,995
Used Ford F-150
2,876 Great Deals out of 212,656 listings starting at $1,000
Used Cadillac DeVille
4 Great Deals out of 1,976 listings starting at $1,750
Used Chevrolet Caprice
175 listings starting at $12,998
Used Ford Taurus
261 Great Deals out of 20,626 listings starting at $1,500
Used Honda Accord
883 Great Deals out of 82,090 listings starting at $999
Used Ford Mustang
396 Great Deals out of 44,403 listings starting at $1,000
Used Toyota Camry
1,080 Great Deals out of 98,047 listings starting at $1,250

Used Cars For Sale

2011 Mercury Grand Marquis For Sale
33 listings starting at $5,900
2010 Mercury Grand Marquis For Sale
5 Great Deals out of 118 listings starting at $2,999
2009 Mercury Grand Marquis For Sale
3 Great Deals out of 110 listings starting at $3,800
2008 Mercury Grand Marquis For Sale
6 Great Deals out of 167 listings starting at $2,995
2007 Mercury Grand Marquis For Sale
6 Great Deals out of 161 listings starting at $2,400