Indicator problem

[Clifford Pope]

The right hand indicators have stopped working. Those on the left are working properly, the RH ones started going very slowly, and now don't work at all.
I have checked all the bulbs, including repeater and warning light on the dashboard.

The switch appears to be working. I have a spare one, so worked out what each wire does and checked for connectivity on the car.

I'm stuck now wondering what to do. I don't understand the wiring diagram. I don't see why switching the power from the flasher to either left or right requires 5 wires. It seems that moving the switch right makes two separate connections:

1) Flasher supply switched to the front and rear indicator lights,
and
2) RH repeater and RH warning light connected to the LH flasher lights. That is weird - why should that make the RH lights work?
Exactly the same, conversely, happens when indicating left, and that works fine. So it's obviously intentional and necessary, but I don't understand it.

I can see in the diagram that the interior warning light and repeater light are connected in parallel to the other flasher terminal, and I appreciate that the warning light is an important part of the circuit. I've checked both lights and cleaned the terminals.


Does anyone understand the indicators and can give any suggestions on what to do next?

[Mike Stevens]

Hi Clifford,

The indicator wiring is quite simple, but is complicated by the addition of hazard flashers - if you have them on your car.

As one side works OK it suggests that the flasher unit and switch (that side anyway) is OK. I would suspect a poor connection on the RH side. I wouldn't worry about the warning lamp (does that come direct from the flasher unit?) or the repeater as the power rating of them is small compared with the main indicators.

I wouldn't suspect earthing as that should affect only one lamp or other not both.

So, look for and check for power down the wiring from the switch to the lights etc. I suspect you have a poor connection somewhere between the switch and where the loom splits to the front and back!

Good luck!

Cheers,
Mike.

[tony]

The S I'm getting back on the road had the same problem. Hazard lights worked on all 6 but no RH indicators.
Replaced with another switch and all is well again.
Tony.

[Clifford Pope]

Sorry, should have said it's Mk1, so no hazards (Unless it has and I've never known !)

The switch appears to be fine - I suddenly realised I could connect up the spare one as a trial just dangling on its wires under the column - no need to actually fit it unless needed, which it seems it doesn't.

The other connection on the flasher unit goes to the two repeaters and also the two warning lights. But the other side of these lights goes not to earth, as I assumed was normally the case, but to the switch, where they are mysteriously connected to the ordinary indicator lights on the OPPOSITE SIDE. The indicator is a 2-pole 2-way switch, making two separate circuits.

This is shown in the wiring diagram, although it is hard to follow and even harder to understand why.

I have always understood that the the warning lights are not just additional loads on the main flasher circuit, but vital to the thing operating at all, providing a trigger to the 3rd terminal of the flasher unit.
So I perhaps need to be checking something on the LH side?

[tony]

I wonder if you have a bad earth connection on either front or rear on the RHS. ? If one bulb is not earthing flashers on that side won't operate. you said initially that indicators were slow on that side, maybe earth has failed completely now.
Could you run a jumper wire to temporarily earth the lamps to see if it fixes the problem, or maybe a test light from lamp terminal to earth ?
Tony.

[red2000chris]

my early mk2 flashers flash much slower on right side than left side. are there separate relays for each side?

[tony]

I'd doubt it.Normally one flasher relay . You may have an odd wattage lamp in the circuit somewhere.
Tony.

[Clifford Pope]

They have suddenly started working again.
Back to how they were - both sides flash ay en even rate, but a bit on the slow side as they always have been.
They start slowly and then speed up a bit after about 4 flashes.
Fitting a different flasher unit doesn't make any difference. I've been round all the bulbs and connections, redone a rather dubious-looking connection in the RH wing, but nothing I have done has actually made a difference.

Anyway, they now work, sort off.
I'd consider replacing with a modern electronic unit if I could understand the wiring. One thing that may account for the apparently needless complexity is the two separate warning lights, rather than just a single one?

[red2000chris]

I'd doubt it.Normally one flasher relay . You may have an odd wattage lamp in the circuit somewhere.
Tony.

I had a look at the relay today, stuck on behind the glove box. its a rectangular clear plastic box with what looks like 2 tiny relays inside!
not original then

[johnconradlee]

The indicators on my Mk1 have always flashed a little slowly but was improved slightly by cleaning the contacts on the relay and relay base. It gets worse (slower) with the trailer board connected so I think I need to add an extra relay.
The Mk1 indicator wiring seems fiendishly overcomplicated (at least compared to nice simple Mk2 type 2 pin relay wiring, which I understand!). The speed of flashing is related to the resistance of the circuit(S) to give you a bulb failure warning which sounds simple enough however the repeaters confusingly aren't earthed and seem to be wired in series through the warning lights on the dashboard.