Rear Lights on with Ignition

[rogerharrop]

I'm in the middle of retrimming my Dart and have now completed the dashboard and it's looking very handsome. However, now when I turn on the ignition the rear lights come on! I thought I'd been meticulous in labelling everything and reconnecting. Any ideas on what I've done wrong please?

Many thanks

Roger

[Vortex O'Plinth]

Just to clarify, is it the tail lamp or the brake lights that come on? If the tail lamps, do the front side lights come on as well?

If it is actually the brake lights and not the tail lamps that come on, the likeliest problem is a shorted out brake light switch.

[rogerharrop]

It’s just the rear lights, not the brake lights and not the front side lights

[Christopher Storey]

The rear lights should be connected to a permanently live power source, usually - in fact almost certainly - unfused , and provided by a brown or brown and white wire to the light switch. If you have a Lucas RB 310/340 control box that brown/white will probably come from the B terminal of the control box . It sounds as though you have the rear lights connected to a power source provided by a white wire, which are ignition controlled and usually fused

[rogerharrop]

Many thanks Christopher

[Ozzsp250]

In case you don't have a wring drawing to work with, see attached.

[rogerharrop]

[JohnM]

Roger,
I'm puzzling how it could be only the rear sidelamps which are coming on, and not the fronts too.
The possibility I'm thinking is that your connections at the rear are crossed - what should be the sidelamps are actually connected to the brake lamp filaments, and that the brake lamp switch is shorted as Nick suggests.

A couple of things to try:
1) if you have the brake system working, press the brake pedal with the ignition (and rear lamps!) on, and see if the brake lights come on too. If they do, you have a strange connection somewhere at the dash loom to rear loom connections.
2) If the brake lights don't come on with the pedal pressed, disconnect a wire from the brake light switch and switch on the ignition. If the lights don't come on, switch on the sidelights - do the rear lights come on brightly and the front sidelights come on? If they do, then the rear sidelamp and brakelight connections could be reversed AND there's a problem with the brake switch.

And as always with SP's - double check all your earth connections , a poor earth can produce many mysterious effects!

Give those a try and let us know what happens,
cheers,
John

[rogerharrop]

Hi John,
I certainly did check that it was not the brake lights - but I will again thanks

[rogerharrop]

Yes, definitely rear lights not brake and defo only the rear comes on with the ignition not the front side lights. Many thanks for all the advice.

I'll work on earths!

Roger