Brake and Ign warning lights.

Todays job was to look at refitting a tacho into my 1975 2200SC. It used to have one many years ago as it is featured in a classic car mag and clearly seen in the photo.
Step one remove speedo....tick
Care note taken to wiring, and took lamp cluster off to limit cross wiring.
Step two locate tacho wiring.... um.
Step three check under bonnet for wiring there.... nope.

Ahh located tacho wiring. I must thank whoever removed the tacho many years ago for the nice and tidy way in which they carefully cut the wires right back into the loom and sealed them Brilliant cheers mate.

Oh well rebuild speedo and forget about tacho. Tick.
Test out car (which was 100% working before)

Lights yep
Horn yep
Brake warning lamp. No
Ign lamp yep.... wait a minute nope doesnae go off.
External check off lights..yep
Fuses ..yep

Not only can i not fit the tacho but now have no brake warning lamp and an ign lamp thats permanently on.

Scatches head... anyone out there got any bright ideas?.

Tom W

Active Member
Do you have a wiring diagram? My guess is you’ve disturbed some of the wiring when you’ve taken the speedo out. The brake warning light and the ignition light are both fed from the ignition switched live circuit. The ignition switched wires are white, and un-fused. There’s a connector behind there’s somewhere where several white wires join. Does the ignition light come on with the ignition, before the car is started? Do the oil pressure and choke lights work?
Fixed the brake light issue.... handbrake was slightly loose and needed tightening. Result.
Checked the lamps and wiring behind the speedo and all looks good and others working fine. Checked with regards to the wiring diagram in Haynes.... leaves alot to be desired does the diagram.

Got underneath to check the wiring.
3 wires in the plug all brown related colours, 2 thick and 1 thin.
Also coming out of the loom is another brown wire with spade connector which is loose but unable to see anywhere to fit it. Rechecking in morning when i can get better access to rear of altenator.
If i need to replace the altenator is it best to go for the 18ac 3500 version for my 2200. Bearing in mind i live in scotland, do regular short journeys and its heavy to push start.
Quick update.
Whilst driving to my better halfs the ign. Lamp began to flicker roughly intime with me reving the engine so....
1.Is it safe to assume the wiring is good.
2.that the altenator is shot.

Answers on a postcard please.
Talking of a wiring diagram. Is there such a thing for a 1975 2200SC RHD with pre engaged starter. If so where is it, as it isnt in any of the Haynes manuals i have and the supplement is for TC models.

The Haynes manual which i grew up on thinking they were the Bees knees i must admit are pretty bad on the whole.