Indicators only work on one side

[gatsby989]

Here's the story on my electrical. Hopefully it will make sense by the end. First, my oil pressure warning light has never worked. Also, some one had fitted a green bulb in the dash, which was always on whenever the car was turned on. No idea what it was for. As for the indicators, the bulbs come on like they're supposed to when I turn on the headlamps, and the indicators work fine on the passenger side. But on the driver's side, I can hear one click from the flasher unit, but that's it. No flashers on the driver's side.

So I replaced the flasher unit, not knowing any better. I also replaced the oil pressure switch, just in case. I had the speedo out to replace the cable, and found out that the oil warning bulb was blown. Not having a spare, I swapped it with one of the bulbs that light up the speedometer when the headlights are turned on, figuring the oil pressure light is much more important.

Now the oil pressure light seems to work properly (hooray). The indicators still work on the passenger's side, and the mystery light installed in the dash now flashes with them. So apparently it is supposed to be a flasher warning light. Which is great, because I always forget to turn the signal off, since it's not the self-canceling kind. However, the flashers on the driver's side still do not work. Also, now neither bulb that lights up the speedometer works. Obviously the blown one won't work, but I figured the other one should still be fine. Hopefully I didn't blow it also some how. Just doesn't seem to make sense to me. But I'm a rank newbie, so... maybe it's something obvious.

Any ideas why the flashers would work only on one side?

[Alec]

Hello Gatsby,

put the indicator switch to the the drivers side and check both front and back lamps, normally you will have one lit permanently and another off. First check is the bulb, and if that is OK (21 W by the way, that is important) it's likely to be a bad earth. If neither are lit, the same checks apply but if no fault is apparent the next place to check is the indicator switch. The flasher unit is common to both sides so if one side flashes then the flasher is OK.

Alec

[gatsby989]

Thank you, Alec.

When the headlamps are on, both the front and rear lights are also on. When the headlamps are off, they are both off. So they behave correctly except that they just won't flash. I will check for good connections as soon as I get a chance. But I'm afraid you're right - it's probably the switch.

As for the speedometer lights... well, I just had the panel light switch off. Oops!

[Alec]

Hello Gatsby,

from that I assume you don't have separate amber indicator units, if so then it is more complicated, there is a special relay that controls the flash of the front and rear stop lights so you will need to check that also. I'm unfamiliar with that particular system so hopefully someone who is can point you in the right direction?

Alec

[MarkyB]

I'd disconnect the extra warning light, it was probably a bodge to avoid buying a new flasher unit.
Does it flash when the drivers side flasher should be working?

[mike.perry]

If one of the indicator bulbs on one side does not work then the flasher will not work as it needs 42W to operate. Check the bullbs and the connections.
What year is the car? This is important.
Speedo lights are 12V

[gatsby989]

The car is a 1957 2 door saloon, with blinkers instead of trafficators. Left hand drive.

The light in the dash does not blink when the switch is on the driver's side. I just hear one click from the flasher unit, and that's it. The bulbs themselves (it has the small amber bulbs in front under the headlights, and the flashers are the same as the tail lights in the back) work, as they turn on when you turn the lights on. Just don't flash on the driver's side. So the connections ought to be good, right?

I suppose I could swap the connections on the switch... and see if then the driver's side, but not the passenger side, flash. If so, then it must be the switch.

[Alec]

Hello Gatsby,

if the lights are on but not flashing then the switch is good, just check what wattage the lamps fitted are, they should be 21 watt, if they are 5 watt then not enough current is drawn to make the flasher relay flash.

Alec

[mike.perry]

I am a little confused when you say that the indicator lights turn on when you turn the lights on. The indicators and lights should be totally separate. The system should have 4 x 21W bulbs plus a 5W warning light. The flasher should be a standard 3 pin 42 + 5W unit.

[gatsby989]

OK, Thank you Alec, I will check that. Didn't realize that the wattage was so important.

Mike: what I mean is when you pull out the light switch to the first click, the little amber lights in front come on (solid, no flashing), as do the tail lights. When you pull the light switch all the way out, the headlamps come on, and the little amber lights stay on, as do the tail lights. Is it not supposed to work that way? I only mention it because it shows that none of the bulbs are burned out.

[bmcecosse]

It is - but they should be twin filament bulbs - the flasher filament is 21 watt, the 'side' filament is only 5 watt. I suspect all that's wrong is a blown 21 watt filament - remove the bulbs and check!

[gatsby989]

Thanks all, I replaced the bulbs and voila, it works. I'm glad it was something simple and cheap! Thanks for your help.

[bmcecosse]