Ignition switch wiring

[Faust]

Another electrical issue... sigh.

Before I removed my dash I made note of all the connections on the ignition switch... or so I thought!

My lights only work with the ignition off (not ideal). Everything else appears to be working correctly.

Does anyone have information/a diagram of the wire colours and the terminal numbers on the switch?

Any help would be appreciated.

Car is a 1970 with the ignition on the steering column rather than the dash.

[Ron Kwas]

Faust;

Late 122 /123 Wiring Diagram: http://www.sw-em.com/123GT-Wiring-Diagram_Euro.jpg See Ign Sw at Item 52

Headlights are not supplied by Ignition Power, they are supplied by Black wire, connected to Battery Power terminal (30). If you were to connect that wire to term 54, Lights current would run through Ign Sw contacts...not recommended!

If you want to make a change, to make lights an Ign Sw controlled function, you must install an Ign Slave Relay. See: http://www.sw-em.com/Ignition_Slave_Relay.htm

Cheers

[Faust]

Cheers Ron.

I'd got the idea in my head that the lights were not controlled via the ignition - you can have them off with no key in the slot - but it strikes me as very odd that they only work (including the high beam flash) with the ignition in the 'off' position.

I'm gonna have to re-think this one!

[Ron Kwas]

Faust;

In the original wiring, Lights work anytime you turn ON switch, and current does not run through Ign Sw, but that means you need to remember to turn them OFF after leaving vehicle or you will have a flat Battery tomorrow...a Lights-On Reminder Beeper is an option.

See: http://www.sw-em.com/electrical_upgr...eminder_beeper

Cheers

[Faust]

Ron,

Think we're making the same point from opposite ends! (I've probably not explained the problem very well).

The lights are independent of the ignition switch as you say. Ignition off or on has no bearing on the operation of the lights.

Right?

BUT

The lights will only work with the ignition OFF.

If I turn the lights on with the ignition ON, they don't work.

This is the problem.

I didn't disconnect the light (or fan & wiper) switches when I removed the dash (just supported them so the connections didn't get damaged).

The ONLY thing I disconnected was the ignition and indicator switches - these all work 100%.

I'll have a poke around under the dash and see what I can find.

[Ron Kwas]

Faust;

Now I understand the question...!

"Ignition off or on has no bearing on the operation of the lights. Right?" Answer: Right!

"The lights will only work with the ignition OFF. If I turn the lights on with the ignition ON, they don't work."
Answer: (...and Ign Sw is the only thing which has been touched...!) I have trouble coming up with an explanation for this action...it sounds like the Light Switch power (Black wire which should be going to term 30 on Ign Sw) is now coming from a point which is powered when Ign is OFF and not powered when Ign is ON, and there is no such point on the Ign Sw that I can think of...the only thing I might suggest is that you inadvertently misconnected the Black (Light Switch Supply) to some wrong point resulting in this action...I have no specific answer but suggest you concentrate your efforts on that Black wire supplying the Light Sw, and inspect and verify wiring of Ign Sw against Wiring Diag and color codes given.

Let us know what you find!

Good Hunting!

[simonvolvo]

Originally Posted by Faust

BUT

The lights will only work with the ignition OFF.

If I turn the lights on with the ignition ON, they don't work.

Perhaps your “thin black” wire (un-switched +ve, which actually leads to the fuse box via the light switch) was connected to terminal 57a of the ignition switch instead of one of the terminals 30. If you look at my diagram you will see that 57a (which is not actually used for anything) only gets power when the ignition switch is in position “O - locked”, i.e. the position in which you can withdraw the key.