Turn Signal Indicator Not Working

[ties581006]

I've done the searches and found nothing quite like I'm experiencing. 1958 100-6 with new wiring harness. The model has only one indicator on the dash. It is not specific to right or left. The turn signals work fine but green dash indicator light is not working. With a new bulb, the filament almost imperceptibly glows when examined carefully outside of the green holder. Replacing the flasher with a NAPA NF550 did not help. It seems unlikely that the old flasher and the new flasher would have exactly the same fault.

The indicator light ground is good: When powered from the flasher's "L" terminal, the indicator light is bright. An (positive earth) LED does not light when powered by the "P" terminal but works when powered by the "L" terminal. I don't think the fault is related to the relay since the indicator light is connected directly to the flasher terminal "P". But I may not fully understand the relay's role in the circuit.

A couple of questions:

1. Should I try a third flasher? Is the NF550 correct?

2. Why does the flasher have a separate terminal for the dash indicator and the signal lights themselves? It would seem that the P and L terminals on the flasher are doing the same thing.

3. Can I tie the indicator to the "L" terminal and just power it along with the turn signal lights?

Has anyone experience something similar? Maybe I'm missing something obvious. Thanks much for any help, suggestions, leads or next troubleshooting steps.

Mike T in Minnesota.

 

[red57]

Not sure if this will help but you say you have a new wiring harness. I had a problem with a new harness from Moss a few years ago. I'm not sure who made it, but it seems to be a common problem with the new harnesses available (from several suppliers at least).

My new harness came with a single wire socket for the flasher indicator light which would rely on the socket base for ground but the green plastic tube the light bulb & socket plug into cannot supply ground.

The original was a two-wire socket because of this.

I was told that there are no sources for these 2-wire sockets so they just used a commonly available single wire socket.

The new harness was also missing the light sockets for the combination gauge and the fuel gauge.

The solution was to transfer my original 2 wire flasher socket to the new harness. I also added the two sockets for the combo & gas gauges

1st picture - original 2 wire flasher socket.
2nd picture - new single-wire flasher socket.
3rd picture - original tach & gas dash sockets (speedo & combo same)
4th picture - new tach, no gas socket (tach & gas same)

Another example of the marginal stuff being sold to us these days
Dave

 

[Rob Glasgow]

Dave, I did the same thing when I installed my new harness from Moss about 6 years ago. I had heard about the issue on this forum, so it didn’t come as a surprise.

 

[Bob_Spidell]

FWIW, I wired my BN2 bare chassis from the manual's schematic. Everything worked perfectly except one of the rear run/brake/turn indicators didn't work correctly. After triple-checking everything and going through the relay, checking and cleaning points, etc. I finally found that one of the wires in the harness was improperly identified; i.e. it had the wrong main and tracer color. Spent three full days of my limited time budget, uh, running that to ground (I'm still a bit chafed about it).

Dad bought all parts from Moss, but they outsource harnesses last I checked, possibly from British Wiring.

 

[ties581006]

Thanks much for the responses. I did source the harness from Moss and had to replace the light sockets with the originals as well. As stated, the indicator light is bright when fed from the power source, so I think the ground and harness is fine. It seems that neither flasher unit provides enough power to light the indicator lamp. The turn signal lights all work fine and flash as expected.

This one still has me stumped. I'm going to try connecting the indicator lamp to the Green/Brown wire on the "L" terminal to see if it works. This effectively makes the three-terminal flasher a two-terminal flasher. Hope I don't destroy the delicate Lucas wiring!!

I'll post my results if I survive the fire.

Mike T.

 

[ties581006]

I connected the signal indicator light to the "L" terminal on the flasher and it worked, sort of. The indicator light flashes brightly when the signals are on but has a dim glow when they are not on. Well, that is an improvement vs the indicator not working at all. I'm tired of being embarrassed when coming to a corner and realizing that my turn signal has been on since the last turn.

Is it just part of the design that the self-cancelling feature only works when making a sharp turn? If there was a solution to that, I'd pursue it.

Thanks again for the help.

Mike T.

 

[Bob_Spidell]

I have LED bulbs in my BJ8's (separate) turn signals and the dash indicators. The indicators are small and not easy to see, but using LEDs in the indicators makes them considerably brighter, but the non-indicating bulb does light up dimly.