Tell tale on indicator stalk not working

Post by **acoylite** » Sat Jun 20, 2009 7:38 pm

Well where to begin,
My Minor 1000 1970 saloon 1098CC failed its MOT on the tell tale warning light on the indicator stalk not working.
I've bought a new flasher unit and a new indicator switch.
When fitting the new indicator switch the tell tale light flashed a couple times.
Since then, its not flashed again.
The other indicator lights work and the flasher unit clicks.
Other items work, such as the horn and interior light.
I'm at a loss, and can't find whats wrong with it.
I have tried a continuity test on the light green wire between the flasher unit and the indicator switch, from the wire to the switch is permanently continuous anywhere on the indicator switch.
I need help, and i want my car back on the road.
Any help/ideas/words would be great
Thanks guys

Post by **rayofleamington** » Sat Jun 20, 2009 8:41 pm

I'm at a loss on this one.
Firstly I'd say to avoid using a multimeter if problems are not fixed first time! The problem is that they can show 12v when there is a feed problem (high resistance connection).
If you use a bulb test circuit (e.g. a home made one using one of those aftermarket dash lights that come in a little plastic tube and have a low wattage bulb) you will find out if the live feed is ok or not. If it is high resistance you won't get enough current to light the bulb.

I've been using one with a 20w bulb - this is completely overkill (drawing nearly 2A) but at least I know that the live is good if the bulb lights. I use the same bulb test circuit for static timing the distributor, and have fitted crocodile clips... It's a very handy tool.

Depending on your meter, the 'continuity' test might pass even with a high resistance connection. For more trustworthy results, put 12v* on the circuit and see if the other end will light up a bulb.

Ideally, connect the live through a small fuse - if you're feed wire is occassionally shorting to ground, you don't want to set it on fire.

My first option after repeating the checks with na bulb tester would be to change the flasher unit for a known working one. I've known people fix these symptoms by changing it, although you want to check the circuits first.

I still use my multimeter, but use it as little as possible. A few years back i'd not been able to find my bulb tester, so I used the multimeter to try and work out why the horn didn't work. An hour of confusion later I gave up and made another bulb test lead!! Using a bulb showed the problem in seconds.

Post by **bmcecosse** » Sat Jun 20, 2009 9:07 pm

I agree - meters can give confusing results - specially on switched earth circuits. Since it flashed a couple of times - I would now check the bulb - if it was new-old-stock - it would be very fragile.
Desperate alternative - to get MOT - is to rig a simple warning light between the two sides of the flasher circuits. When one side is activated - the bulb earths out through the other side - and flashes with the lamps. doesn't need to be anything fancy - all they need for MOT is a lamp flashing! Well done if that's all that's wrong with your car for the MOT - oh, and welcome to the Forum !

Post by **rayofleamington** » Sun Jun 21, 2009 4:19 pm

Desperate alternative - to get MOT - is to rig a simple warning light between the two sides of the flasher circuits.

Or rig up 2 seperate lights, one from each side to earth... I had that on my 54.

Post by **d_harris** » Sun Jun 21, 2009 7:15 pm

Test from the pin on the flasher unit which the light green wire comes from. That should flash 12v as the indicator flashes. Then all you need to do is run a feed from there to a tell somewhere visible to the driver and eart to the body (I've used one of the screws which hold the glovebox lid on)

And welcome!

Post by **mike.perry** » Mon Jun 22, 2009 8:54 am

The failure of the indicator warning light to work when indicating either left or right normally means that one of the indicator bulbs is not working on that side. Check that the indicators are definately working.
If the indicators are OK then you can get around the problem by disconnecting the light green warning light wire from the P terminal of the flasher unit then disconnecting the wire onto the oil filter and connecting it to the P terminal. The oil filter warning light will now operate as the indicator warning light which will get you through the MOT