Headlight Help

[MarkC]

Commuted to work in my Tii yesterday morning and when I turned the headlights on, there was a noticeable delay (1 sec or so) from when I pulled the dash knob to when the lights actually illuminated.

 

Car drove flawlessly to/from work.

 

Yesterday evening I went to drive the car and the headlights (low beam) would not illuminate.

• Engine was running
• High beams still work if you pulled back on the turn signal lever, but did not illuminate if you pushed it forward (or I would've just drove it like that)
• All other lights were functioning (turn signals, marker lights, brakes, etc.)

 

I checked fuses, all were intact but did not have time to look into it further as I needed to be somewhere.

 

I plan to look into this over the weekend - appreciate any direction on where to start testing things.

 

TIA

[dlacey]

Dirty fuse ?

[MarkC]

5 minutes ago, dlacey said:

Dirty fuse ?

No, the fuse box was cleaned up & sorted a couple months ago and all the fuses were intact and clean.

[John_in_VA]

If you have dual-filament H4 bulbs (or even sealed beams) it is possible for the low beam portion to be burned out.

https://www.rallylights.com/light-bulbs/l/h-4

Edited November 4, 2022 by John_in_VA

[MarkC]

5 minutes ago, John_in_VA said:

If you have dual-filament H4 bulbs (or even sealed beams) it is possible for the low beam portion to be burned out.

https://www.rallylights.com/light-bulbs/l/h-4

Perhaps, I will check those... seems odd that they both would be delayed illuminating together in the morning and then both not be working at the same time in the evening.  I've had bulbs burn out in cars within quick succession but not at the same exact time.  Thanks for the response.

[ingramlee]

Same thing happened to me a few months ago. I took the headlight switch apart... very carefully... and thoroughly cleaned the inside with contact cleaner.  Put it back together and it's worked perfectly ever since. I did have to wrap the switch with a ty-wrap to keep it together, but it works. Nobody sees it behind the console anyway.

[MarkC]

1 hour ago, ingramlee said:

Same thing happened to me a few months ago. I took the headlight switch apart... very carefully... and thoroughly cleaned the inside with contact cleaner.  Put it back together and it's worked perfectly ever since. I did have to wrap the switch with a ty-wrap to keep it together, but it works. Nobody sees it behind the console anyway.

Good to know...  I looked at the diagram, how does the switch come out of the dash (so I don't mangle anything up)?

 

UPDATE: Disregard, been searching around on here and found other posts.

Edited November 4, 2022 by MarkC
Found answer to follow-up question asked

[John_in_VA]

The headlight relays can become balky over time, leading to the delay you mentioned.  Prying off the cover to inspect & clean the contacts may lead to favorable results!

[John76]

7 minutes ago, John_in_VA said:

The headlight relays can become balky over time,

Yes indeed. Check the relays before tearing into the switch (although still a good idea to keep clean).

Here's a map of the relays... should be similar for all square tails.

 

[Mike Self]

You didn't indicate what year your tii is, but only squarelights have relays on their headlights, and then only on the low beams.  Roundies do not have relayed headlights--and six fuse roundies dont even have fuses for their headlights.  

 

Since you've checked your fuses--didja put your finger on the relevant fuse while the headlights were on to see if it was hot? Hot fuse = poor contact.  

 

Since you had a malfunction of both low and high beams, I'd suggest looking at the high/low beam stalk; that's the only place where circuits for both low and high beams meet.  It might just need a bit of cleaning inside (tuner cleaner) or the contacts may be burned.  Remember, without a relay all that current for those headlights pass through that poor little switch--same as the headlight switch.  For 12 fuse roundies, it's relatively easy to add a relay to the wiring; I did that for the high beams on my '73 many years ago, and it works well.  PM if you'd like a copy of the relevant column.

 

Cheers

mike

[MarkC]

11 hours ago, Mike Self said:

You didn't indicate what year your tii is, but only squarelights have relays on their headlights, and then only on the low beams.  Roundies do not have relayed headlights--and six fuse roundies dont even have fuses for their headlights.  

 

Since you've checked your fuses--didja put your finger on the relevant fuse while the headlights were on to see if it was hot? Hot fuse = poor contact.  

 

Since you had a malfunction of both low and high beams, I'd suggest looking at the high/low beam stalk; that's the only place where circuits for both low and high beams meet.  It might just need a bit of cleaning inside (tuner cleaner) or the contacts may be burned.  Remember, without a relay all that current for those headlights pass through that poor little switch--same as the headlight switch.  For 12 fuse roundies, it's relatively easy to add a relay to the wiring; I did that for the high beams on my '73 many years ago, and it works well.  PM if you'd like a copy of the relevant column.

 

Cheers

mike

Only issue was the low beams, high beams functioned pulling back on the stalk, they just wouldn’t stay on when pushing it forward.

[MarkC]

Update/Solved:

 

It was the headlight switch behind the dash. Pulled everything apart, found one I had from a ‘74 parts stash, swapped it in & I saw the light.

 

Thanks everyone for all the help.

 

Now I can take my time cleaning up and/or repairing the bad one for a spare.