LAS VEGAS DAVE

HEADLIGHT PROBLEM

Recommended Posts

What could cause the drivers side low beam headlight to go out only when the light switch is pulled all the way out with the dimmer switch in the low beam position. The low beam works fine with the light switch in the next position inwards so the bulb must be good. The high beams work in all light switch positions. 

Edited by LAS VEGAS DAVE (see edit history)
  • Like 1

Share this post


Link to post
Share on other sites

With the switch all the way out (fourth position), the driver's side should be on high beam, even with the dimmer switch in the low beam position.  The only light that switches in that mode is the passenger side.  In the third position, both lights will switch.  Also, the parking lights will go out when high beam is selected, and will be on when low beam is selected.

  • Like 1

Share this post


Link to post
Share on other sites
4 hours ago, DonMicheletti said:

Read the manual - I believe that is the it is supposed to be,  I think they explain the logic too.

Don do you think the manual says the DRIVERS light is supposed to go completely out with the switch in the fourth position and the DIMMER on LOW BEAM?  Keep in mind that my car is a 38 not a 37.

 

 

Edited by LAS VEGAS DAVE (see edit history)
  • Like 1

Share this post


Link to post
Share on other sites
7 hours ago, jeff said:

With the switch all the way out (fourth position), the driver's side should be on high beam, even with the dimmer switch in the low beam position.  The only light that switches in that mode is the passenger side.  In the third position, both lights will switch.  Also, the parking lights will go out when high beam is selected, and will be on when low beam is selected.

 

Jeff, you are right but I never noticed until you posted  that the parking lights go OUT if the light switch is in the fourth position and the high beams are on. They come back ON if the dimmer switch puts the LOW beams on. However in the high beam position my drivers side light goes OFF COMPLETELY if the light switch is in the fourth position. If the light switch is in the third position both high beams work as expected and also the low beams work as expected and both parking lights are always on.  To me it seems plausible that my drivers side light goes off if I hit the high beams in the fourth position so as not to bother the on coming traffic. It seems the fourth position should be used where you mostly use dim lights such as driving around town. Position number 3 is just like modern car lights with a normal high and low beams. Still I have a hard time thinking they would ever want one of the headlights to just shut off completely although when that happens the running light magically comes back on. Did they have drugs in 1938 as its possible the guy that designed the headlight circuit was on them.

 

Edited by LAS VEGAS DAVE (see edit history)
  • Like 1

Share this post


Link to post
Share on other sites

Exactly as my '39 works - when in fourth position with high beam on the left bulb goes out.  With high beam off, fourth position lights are on.  High beam on at both lights in the third position.  I assume manual wording "asymmetrical" is what this is called....?

  • Like 1

Share this post


Link to post
Share on other sites

Yesterday I found some thread here on the AACA that had a table of "what is on and what is off" in the various positions of the headlight switch for 1938 Buick. I have been searching for a half an hour now and cannot find it. If anyone knows where that thread is, please post.

 

I don't know what the source of the table was. I just remembered it was different than 1937, so did not post it in GaryW 's thread, so as not to muddy up the waters over there.

 

The main difference I remember is that the in position 3, both 1938  headlights beamed up and down with the floor switch.

 

I do not remember any position with one headlight out.

 

Does anyone have a wiring diagram for 1938? How about an owners manual that explains what should happen?

 

Edited by Bloo (see edit history)

Share this post


Link to post
Share on other sites
1 hour ago, jvelde said:

I assume manual wording "asymmetrical" is what this is called....?

 

Maybe, but in 1937 (and 1936) "asymetrical" meant Passenger side on low and drivers side on high. (They shine across each other, so the passenger side light is the one that shines into the oncoming lane.)

Share this post


Link to post
Share on other sites
2 hours ago, jvelde said:

Exactly as my '39 works - when in fourth position with high beam on the left bulb goes out.  With high beam off, fourth position lights are on.  High beam on at both lights in the third position.  I assume manual wording "asymmetrical" is what this is called....?

 

My car LIGHT CIRCUIT is EXACTLY like yours and it was made late in 1938 and the paint on the motor is also like 39! I am amazed at this circuit, when did they do away with this and return to the way cars headlights are normally wired? My car also has a different fuel pump FROM THE FACTORY with a vacuum assist on it with factory fuel lines. I found documentation showing that as an option. 

Share this post


Link to post
Share on other sites
1 hour ago, LAS VEGAS DAVE said:

when did they do away with this and return to the way cars headlights are normally wired?

 

That wasn't a standard until 1940 when sealed beams came out.  Before that, cars existed that simply dimmed but there were also cars that did not, and I have even seen documentation of something that had a five position switch. I don't remember what it was.

Share this post


Link to post
Share on other sites

I had a 33 Ford and it just had regular headlights. Henry wasn't spending any extra money on wire or special headlight circuits. It took him forever to go with hydraulic brakes.

 

  • Haha 1

Share this post


Link to post
Share on other sites

Bloo,

 

I can't find where anyone has posted that on the forum. Attached is the 1937 Service Manual explanation of the Multibeam headlights for both 1937 and 1938. While the page numbers and a little bit of the formatting is different, the 1937 and 1938 Service Manual explanations are identical. This does not surprise me as they both use the same lenses, reflectors, trim rings, and most of the same internal headlight pod parts. There is some minor changes in the horizontal aiming assembly part numbers. The headlight pods themselves are different, which I think is mainly just different chrome trim. 

 

IMG_20171121_221304224.jpg

IMG_20171121_222413743.jpg

IMG_20171121_222419710.jpg

IMG_20171121_222434278.jpg

IMG_20171121_221216176.jpg

IMG_20171121_221230837.jpg

IMG_20171121_222543193.jpg

IMG_20171121_222556112.jpg

  • Like 1

Share this post


Link to post
Share on other sites

What about the 39, were they different? Is it true that the headlight switch in 37 and 38 had different part numbers? If so what is the difference?

BADGE.JPG

Share this post


Link to post
Share on other sites

The 1939 Headlamps are different. The 1937 headlamp switch and the 1938 headlamp switch do have different part numbers but I have no idea how, if at all, they are different.

Share this post


Link to post
Share on other sites

My 38 drivers headlight goes completely off in position 4 with high beams selected. Another guy with a 39 says his also does that. Do all 39 models do that?

 

BEST FRONT.JPG

Share this post


Link to post
Share on other sites
5 hours ago, MCHinson said:

Bloo,

 

I can't find where anyone has posted that on the forum. Attached is the 1937 Service Manual explanation of the Multibeam headlights for both 1937 and 1938. While the page numbers and a little bit of the formatting is different, the 1937 and 1938 Service Manual explanations are identical. This does not surprise me as they both use the same lenses, reflectors, trim rings, and most of the same internal headlight pod parts. There is some minor changes in the horizontal aiming assembly part numbers. The headlight pods themselves are different, which I think is mainly just different chrome trim. 

 

Thank you for posting that!

 

The 1938 manual pages do clear up one point, the one that has been bothering me the most.

 

"The circuits of the control switch have been modified to enable switching from the upper beam to the fully depressed beam when in the third position as well as from the upper beam to the asymmetric passing beam when the switch is in the fourth position by operating the foot switch."

 

I don't see how they could have accomplished this without changing both the wiring harness and the switch.

 

 

 

 

Share this post


Link to post
Share on other sites
5 hours ago, Bloo said:

 

Thank you for posting that!

 

The 1938 manual pages do clear up one point, the one that has been bothering me the most.

 

"The circuits of the control switch have been modified to enable switching from the upper beam to the fully depressed beam when in the third position as well as from the upper beam to the asymmetric passing beam when the switch is in the fourth position by operating the foot switch."

 

I don't see how they could have accomplished this without changing both the wiring harness and the switch.

 

 

 

 

Bloo,

 

That same text also appears in the 1937 Service Manual. I am guessing that must describe a change from 1936 and they left the same text in the 1938 manual as well. Perhaps the word was still just getting out to people, or maybe they just did not want to bother to update the text since the circuit was identical to the 1937 circuit. The only curious item is that the 1938 switch has a different part number. Perhaps it came from a different supplier, or perhaps there was some minor improvement of some component. From the two service manuals, it appears that the 1937 switch and the 1938 switch operations are identical. 

 

With a quick glance I see a difference in the source of power for the dash lights and map lights being the only difference between the 1937 and 1938 wiring harness. Maybe you see something else.

IMG_20171122_084213154.jpg

IMG_20171122_084241989.jpg

Share this post


Link to post
Share on other sites

Here are the pages on headlights from the '39 Service Manual - as you will note, it references the '38 Service Manual for items that did not change, and discusses what did change.  Really convenient in trying to piece things together by bouncing between two manuals!

CCF11222017_00000.thumb.jpg.cb45d36df746c6a0c0457b452a920ef4.jpgCCF11222017_00001.thumb.jpg.13c07e4ba232a4979a4ec45a7a424892.jpg

 

Edited by jvelde
Made scans to show pages better. (see edit history)

Share this post


Link to post
Share on other sites

After reading those several times... I don't see it.

 

I don't see how it can be normal. I am still trying to get my head around how they made All-High/All-Low work in position 3. If I can ever figure that out, maybe we will have the answer. For the moment I suspect that that contact at the very end of the switch, pin 12, has failed. I suspect several people have the same failure.

 

It looks (for the moment) like all 37-39 should behave like the 1938 table above, with the possible exception of the fender lights. This guess could change...

 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now