TR6 TR6 TURN SIGNAL ISSUE

[trbob]

My '75 TR6 turn signals work fine in left turn mode but in right turn mode the flasher clicks rapidly and the lights don't flash. The indicator light in the dash flashes but it is very weak. I have torn out all of my hair trying to diagnose this but can't come up with an answer. I've heard there are more modern flasher units available which will make the system more reliable. Any suggestions?

 

[DougF]

It could be a poor ground or maybe a bad socket/bulb. Swap the bulbs first and then the sockets from left to right, right to left to see if the problem follows. If so, it's a socket or a bulb.
Clean the tail light housing edge that makes contact with the socket. Also clean the contacting surface of the socket. Use a light sandpaper or steel wool. I prefer sandpaper.

 

[trbob]

Thanks. I'll check it out.

 

[DrEntropy]

The flasher depends on a load for it to cycle. If a bulb is bad or a ground is weak it will flash rapidly on the affected side (as described). Check all bulbs and grounding points on the right-side circuit. If the bulbs at both ends are also flashing rapidly or not at all it'll be a ground prob (usually).

 

[piman]

Hello Dr E,

"The flasher depends on a load for it to cycle",

Quite correct but the effect is the reverse of what you described. A bad lamp or earth causes the other lamp to stay on permanently as there is insufficient load to activate the bi-metallic relay.
If the relay is flashing very quickly, and no lamps flash it is likely a short circuit to earth causing too much current to flow through the relay, and no voltage to light the lamps.

Alec

 

[tomshobby]

Hello Dr E,

"The flasher depends on a load for it to cycle",

Quite correct but the effect is the reverse of what you described. A bad lamp or earth causes the other lamp to stay on permanently as there is insufficient load to activate the bi-metallic relay.
If the relay is flashing very quickly, and no lamps flash it is likely a short circuit to earth causing too much current to flow through the relay, and no voltage to light the lamps.

Alec

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[TR3driver]

I disagree ... the effect varies with which exact flasher you have installed and how much the current is off. I have seen rapid flashing, slow flashing, and only the dash lamp flashing, all as a result of low current through the flasher.

Here in the US, genuine Lucas components aren't available on every street corner, and many other makers offer 'compatible' components that may not behave exactly the same.

 

[DrEntropy]

With the described rapid flashing of one side (other side functioning normally), the flasher unit or a bad (insufficient) ground on one of the housings will cause it. The malfunctioning side hasn't the current draw to get the flasher to 'throw over' completely. This has been my experience. A "steady on" at one end or the other would indicate a bad bulb in the circuit. I maintain it is a grounding problem: at the housing-to-chassis or the bulb bases are corroded. A good cleaning of bulb bases and sockets is in order first... ScotchBrite, not steel wool, please! If that gives no joy, start checking/cleaning the unit grounding points. An analog VOM would help in chasing the problem, too.

 

[tomshobby]

Hi Randall and Doc,

I see your point.

Most of my inexperience in this area is not with LBC's. Never had a problem with my LBC's that jiggling a bulb or replacing one did not cure.

On other cars when the circuit resistance was added to by adding more lights or a trailer hookup the lights would flash very rapidly because of the increased current draw. In that case a "heavy duty" flasher corrected the problem. Also a short between the bulbs and the flasher unit would cause the same thing.

One way to find the problem would to use a volt meter to see if the circuit has full voltage and an ohm meter and check the resistance in sections of circuit. A comparison between the side that works and the side that does not should give a good clue to the problem.