Rear tail lights come on

[Stormy]

I went to the garage to work on my 1963/64 Avanti R1 and noticed the tail lights [red] were on.  The battery was on a trickle charger so the day or two spent with the tail lights on did not run the battery down.  I checked the above windshield light switches and all were off.  Headlights were off.  Key was out of the ignition.  I pressed on the brake pedal a few times, but the tail lights remained on.  

Any thoughts on what to check to get the tail lights off and operating properly ? 

[studegary]

13 minutes ago, Stormy said:

I went to the garage to work on my 1963/64 Avanti R1 and noticed the tail lights [red] were on.  The battery was on a trickle charger so the day or two spent with the tail lights on did not run the battery down.  I checked the above windshield light switches and all were off.  Headlights were off.  Key was out of the ignition.  I pressed on the brake pedal a few times, but the tail lights remained on.  

Any thoughts on what to check to get the tail lights off and operating properly ? 

First, are you sure that it is the tail lights and not the stop lights?  It sounds like your stop light switch has "died".  

[Stormy]

 

1 hour ago, studegary said:

First, are you sure that it is the tail lights and not the stop lights?  It sounds like your stop light switch has "died".  

Well, I guess I cannot tell.  Aren't the tail and stop [brake] lights using the same bulb and red lense ?  

[mfg]

I agree with Gary....It sure sounds like the hydraulic stop light switch on your Avanti has failed in the 'closed' position....A very common problem as these switches age.

[studegary]

10 minutes ago, Stormy said:

 

Well, I guess I cannot tell.  Aren't the tail and stop [brake] lights using the same bulb and red lense ?  

Yes, with different filaments.  Disconnect a wire at the stop light switch and see if the lights go out.  

[Gunslinger]

It could also be the plastic bushing to the brake pedal has worn and the pedal is sagging for lack of a better term...and that's activating the brake light switch.  Ask me how I know.  I do admit the bad brake light switch is the more likely culprit.  

[Stormy]

Thanks to you all.  The Brake light switch is located where ?   Wish I knew all there is to know, ——-maybe my second Avanti will be easier when I get it.  

[JLBKY]

If your Avanti has an OEM  style M/C  ( single reservoir ) then  the switch is located at the end of the M/C..........look for two wires connected to it. IF it has a dual chamber MC it could be on the M/C as well, or be mounted somewhere below the M/C............follow the brake line down from the M/C towards a front junction block...........it could be in that area. OR, the hydraulic switch could have been replaced with a mechanical switch, and relocated to under the dash, where it is operated by the brake pedal "arm".

I'd stronley suggest that you acquire a Shop Manual and a Parts Book. The wiring diagram is included in one of them, I don't recall which. Once you get a wiring diagram, have it copied in a much larger size so you can actually read it.  OR, I recall there are vendors that have larger and color coded wiring diagrams available. Perhaps some here on the Forum can weigh in and tell you where you can buy one.

John

[Stormy]

John, thank you.  I'll look where you say.  I know I have a single reservoir Master Cylinder.  I suspect it is not the original one.  I do have all of the publications you mention and all others I have seen available.  Sometimes applying them to the terms familiar to many mechanics is a bit difficult, but I am learning from all of you.  Thanks, to all.  Daryl

[Gunslinger]

The hydraulic brake light switch is easy to source and inexpensive...it was used on many cars contemporary to the Avanti.  The issue now is twofold...replacements now are usually made offshore and they simply don't last.  Another issue is they seem to be sensitive to DOT 5 silicone brake fluid if you use that (my advice...don't) and will also fail early.  Why...no one seems to know.  My advice about DOT 5 brake fluid is also arguable...some use it without issue but many argue against it.  

When you replace the switch...immediately bleed your brakes of air since removing the old switch introduces air into the system.

Another option is to leave the brake light switch where it is, disconnect its wires and install a mechanical switch under the dash.  It might take about an hour of work but it's more reliable.