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TR4/4A Headlights Blink Off

bammons

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Well like a lot of British car owners I am using the cold weather to fix some things. I finished my restoration in May and put about 1600 miles on it. One disturbing issue that has shown up twice is at night when the headlights will turn off while driving. Both times I was slightly curving (turning) going down the road. This isn't as fun or exciting as you might think it would be and it is worse when the wife is with you (both times). I might mention that I have not driven it alot at night so the two times is way too much to ignore. So my first thought is the wires are pulling in the steering column maybe at the headlight switch. The wires (TR4A) are very tight in there. I can't remember but I think they are up against the steering rod and could be pulled by it when turning. Before I start on this I wanted to see what others have experienced and what they did about it. By the way I have LED lights. Am I looking in the right place and what is the fix? Bruce
 
I think you're on the right track. Since both lights are going off, it can't be just a connection at the lamps themselves; it has to be something common to both. That sounds like the switch or wiring in the steering column. The problem is to try to recreate it; unless you can do that, you're working in the dark (so to speak).

I'd take a good look at all the connections. There is a limited number of them; wiggle them all and see if that causes the lights to go out. Is this new wiring? If not, clean the connections well and in either case make sure they are tight. If you can reproduce the problem, see if the lights come on again if you operate the switch--that is a strong indication that the problem is in the switch.
 
Ok I will check all connections. It is a new wiring harness and also a new headlight switch. And I will try to create more slack in the steering column. I know you are correct if I can recreate the problem, it would be easier to remedy but sometimes on electrical issues that is hard. It actually stays off longer than a blink, I had to hit the brakes not being able to see where I was each time. What has me somewhat confused is I have made sharper turns (such as pulling out of a side road) and not had it happen. i just wanted to see if this was anything others had seen before I tackle it. It is both lights at once so that does lower the number of connections to those common to both. I will wait a day or two before i work on it to see if any others have more advice. Thanks Steve. Bruce
 
I am not sure if you have the foot operated dimmer switch. But that was a source of a similar problem for me.
Charley
 
Bob and Charley -OK I am not particularly proficient in electric diagnosis so what exactly are you saying and what would I be looking for specifically? I do have a foot operated dimmer switch. New wiring but older foot switch. More help please. Bruce
 
I had the same problem with a dimmer switch in a tr3 as Charley. All I had to do was put my foot lightly on the dimmer and the lights went out. Perhaps drive in the day with the lights on and keep an eye on the amp meter as you are poking around at the switches and see if meter moves indicating no draw.

I would get a new dimmer switch
 
Adding up 1 and 1 and getting 6 here...

If the lights go out in a turn... AND you have the foot-operated dimmer switch... Could you be bracing yourself in the turn with your left foot, or allowing centrifugal force to make your left foot fall over onto the switch? Either scenario could create the kind of light (erm... "gentle" ) contact described above that could make the low beams flicker out. Just a thought, but easy enough to replicate that you could at least rule it out.
 
I agree with the above notes regarding an inadvertant touching of the foot dimmer especially in a curve. Easy enough to replicate while sitting in your garage by touching the dimmer with your foot. My cure was to get a replacement dimmer, But I did verify that as the cause prior to getting the replacement. No sense replacing good parts.
Charley
 
Find the wire that provides power to the dimmer at the dimmer. Wiggle the wire at its connection to see if lights go out. The wire can appear connected to its terminal but not be due to strand breakage. Or it may be the switch. BTW, the other 2 wires on the dipper switch are the high and low beams.
Bob
 
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All the butt connectors must have a dab of dielectric grease to ensure good service.DO NOT forget
the grounding connections. Do it right and do it once!!! Most of the electrical demons are of the
owners making.
Mad dog
 
Thank everybody for the help. I suspected the switch on the column and decided to take it out. Not fun, much easier to get under the dash with no seat. It was new but seems to be shoddy construction (Tiawan) not Lucas. A " contact" fell out when I got it to the bench. Looks like original Lucas is not available anymore. So I will order a new one. I have not tested the headlight dimmer as described above yet as I started on the switch first. I also will replace the rubber connectors with new as I used the old ones and I will use dielectric grease on these. I am going to see if I have the original switch but I remember it had a burned wire when I took it out. These new switches are poor. And yes Mad Dog everything is my fault according to my wife so I accept that. Bruce
 
Gentlemen -

Lucas switch.jpg
 
Never forget that the original Lucas switches can be easily taken apart for cleaning and repair.
In my view "getting a new one" can cause a lot of problems.
Last week I had the fun of reconditioning the turn switch on my Morgan. The problems of age/dirt
are gone now and it will, I am sure ,out last me.( don't have another sixty in me)
Mad dog
 
I did find the original Lucas that thankfully I did not throw away (a lesson I finally learned). The flash to pass wire was fried so I am simply taking it off and installing it like that. Could not talk myself into contortions today so will do that tomorrow. Bruce
 
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