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Topic: Newbie with no low beams (again) (Read 2295 times) previous topic - next topic

Newbie with no low beams (again)

Greetings all - been lurking for awhile, decided it was time to register and partite.

Just received mom's 87 tbird as a gift.  59k miles, 3.8l, digital speedo with buttstuffog gauges, not driven in past 10 years, garaged every day of it's life (she's the original owner).

Anyway, I'm experiencing what appears to be the all too common no-low-beam bug.

Here's what I've found during my testing:

- Flash to pass appears to be working (with key on, and multi function switch mounted to column).  If high beams are on when using flash to pass, relay clicks and headlight intensity changes.  I'm assuming that's the low beams illuminating.  With low beams selected, flash to pass goes from flash to nothing.

- Door chime occasionally sounds without key in ignition (saw a thread on this - wanted to include it).  Jiggling the switch silences the chime.

- Cleaned small gounding lugs above each headlight.

- Removed multi function switch 2x.  Disassembled and cleaned contact points and connecting lugs using emery cloth and a pencil eraser.  No apparent damage (melting, extreme wear) but some of the connecting lugs seem to be a different color.

- No power to headlight plug when low beam is selected - tested using VOM.

- Headlight switch doesn't seem to heat up.

- Bulbs are good - tested.

- I've got the auto dim and shutoff.  Tried unplugging the sensor on the mirror.

I've run through the electrical threads and found multi function switch, relay, and wiring as the main culprits.  I'm wondering if somebody could give me a definitive solution, if more info is needed, or if this is going to be a search and destroy.

Thanks in advance for your help.  This place is great!

Newbie with no low beams (again)

Reply #1 –
I'm wondering if it's the headlight switch itself; they seem to be a common problem. You could grab one for cheap at the junkyard and give it a shot.

Quote
No power to headlight plug when low beam is selected - tested using VOM
Is this the plug at the front of the car, or the plug for the switch?

Welcome to the forums!
[SIGPIC][/SIGPIC]

Newbie with no low beams (again)

Reply #2 –
Sorry - front of the car.

Newbie with no low beams (again)

Reply #3 –
I guess I forgot to mention that the high beams are working.

Newbie with no low beams (again)

Reply #4 –
Quote from: kevbey;155855
I guess I forgot to mention that the high beams are working.



naw,, i assumed that was what you meant by the topic subject.

how does the circuit operate when auto headlamps are turned off?

snag those pics i posted to the other thread like yours.  Those drawings are a little more applicable on your car.

so,,,,,,,,
with hi beam selected, you have no power out at the lamp / bulb connectors? correct?

ive never had to read continuity across halogen filiments before, i suppose they read the same as regular filiment bulbs but i could be wrong.

Newbie with no low beams (again)

Reply #5 –
I had this exact same problem in my 'Bird when I bought it, It turned out to be a bad headlight switch. As stated earlier, you can usually find one at a JY pretty cheap, that would be the first thing I would check.

Newbie with no low beams (again)

Reply #6 –
I have been studying jcassidy's EVTSM diagrams in another thread that he refered you to.
You have a headlight dimmer relay. When the relay is energized (picked) you have high beams. When the relay de-energized (dropped) you have low beams.

If you have Hi-beams with the mulitfunction switch in Hi and no Hi- beams when the switch is in Lo, the dimmer relay is picking and dropping like it should.

That just leaves the normaly closed contacts of the dimmer relay and wiring and connectors from there to the lights.

First you need to find the dimmer relay (good luck).
Page 86 of jcassidy's EVTSM says behind LH side of I/P.

If you pull the relay out, you can check the normaly closed contacts with your OHM meter. See the "headlamp dimmer relay terminals" diagram on EVTSM page 84.
Check from where wire 15 R/Y enters and wire 13 R/BK exits.

Newbie with no low beams (again)

Reply #7 –
lemme see if i can find that dimmer relay softouch...brb

---------------

ok found a pic of it,,,page 83

I see what you mean now,, that dimmer relay is like the main dude!!
I swear i was bout to tear out 20 some pages in this thing and lay it all out in a line on the kitchen table so i could see what the hell i was doing.  guess i could've just printed them out to but i didnt think about that when i was getting frustrated.

Newbie with no low beams (again)

Reply #8 –
and the rest,, connecting to the ones on the other thread

Newbie with no low beams (again)

Reply #9 –
my neck hurts
RIP 1988 and 1990 Lincoln Mark VII LSC
I welcomed the dark side and currently am driving a 2000 Dodge Durango SLT plus, with a 5.9, Code named project "Night Runner"
Shes black on black, fully loaded, with headers, 180 tstat, e fan, straight exhaust into a cherry bomb vortex ler, full tune up, ported intake and T/B, MSD coil, and round aircleaner.
Mods to come: Fully rebuilt and heavily modded 46RE, and a richmond rachet locker.
my $300 beater ;)
R.I.P Kayleigh Raposa 12/18/90 - 2/24/07

Newbie with no low beams (again)

Reply #10 –
Sorry - haven't been able to check in for a couple days.  cougarcragar - Thanks for the welcome.  83heritage, softtouch, & jcassity - Thanks for the info and the pics.  I guess I know what I'm doing this weekend (in addition to putting brakes in my daughter's car and finishing my deck).  Thanks again everybody for the help.  I'll post my findings, and hopefully the fix.

Newbie with no low beams (again)

Reply #11 –
Haven't had the time to do anything other than replacing the multi-function switch (didn't help).  Started the car this morning, hit the flash to pass (with the lights off) rather than the tilt, and the high beams stayed on.  Turn the headlights on and off, shut the car off, and the high beams stayed on.  Had to disconnect the battery.

This afternoon I removed the headlight switch, auto light adjuster wheels, and the multi function switch all at the same time.  When I re-connected the battery, the high beams came on.

I'm thinking one of the auto light relays took a dump.  Can anyone tell me if I'm on the right track, and if so, how do I remove the @#$% things from the 'hanger'?

Newbie with no low beams (again)

Reply #12 –
Are you saying the Hi beams come on with the main light switch, the multi-function switch and the autolamp on/off and time control all out of the car?
If so, it looks like it will have to be the autolamp relay #1 or the flash to pass relay.
Remove fuse #10 to eliminate the flash to pass relay.

Removing the autolamp controls disconnected a ground for the light sensor amplifier. This may cause the amplifier to go out of control and pick the autolamp relay. Don't know but just something to suspect.

Newbie with no low beams (again)

Reply #13 –
wow, back from the grave on this thread:D

Newbie with no low beams (again)

Reply #14 –
I'm gonna ressurect this one more time.  Turns out it was the dimmer relay (one of the grey plug relays).  Of course it had to be the bottom relay on the right-hand side of the relay 'rack', so it was a blast to get to.  Anyway, $13 at NAPA.