40 replies to this topic

[sonscar]

Time for dirty hands and a Meter or test light.At its most basic the electricity goes from the battery to a switch to the light to the body then back to the battery.It does not care about the insulation colour(we might)as long as it is going to the right place.
Test the switch,it should connect to none of the terminals,then one of them and then two of them.If this is faulty there is no validity in checking anything else until it is.Despite its complex looks the electricity is very simple.Only look at the wire that doesn't work,ignore the rest.Have fun,Steve..

[Marc13]

Couldnt see any sign of anything burnt.

Any idea on the switch type/place to buy?

Also, just a thought. Is it more likely to be the switch being faulty or a wiring issue?....was thinking...if you get the wiring slightly wrong on a light switch in your house, you can get a situation where the light stays permenantly on, regardless of the switch being on or off...can this same thing happen in a car?

[sonscar]

TEST the switch.It should have three seperate pins at the rear.One pin is the power in,one pin is the side lights and one pin is the headlights.Using a meter or testlamp it should be easy to identify these.In one position there should be no continuity between any pin.In another position there should be continuity between two of the pins,one of these is the sidelights.In the last position there should be continuity between all three pins,this is the headlights.

If you cannot do this it may be wise to seek pro assistance as it is relatively easy to let out the dreaded magic smoke and that will be a world of hurt.

Google a simple lighting circuit,watch how it works,randomly stabbing about and changing things often disappoints.Persevere and you will become a wiring GOD,Be safe Steve..

[Ethel]

If it's an original Lucas switch it's have more than 3 spade connections & some are common

 

https://www.carbuild...WAaArqIEALw_wcB

 

 

If you have 3 wires:

 

Brown to 1 or 7

 

Red to 4      (6) numbers in brackets will make it work in reverse, if  down was off it'll be up instead.

 

Blue to 8     (2)

[Marc13]

If it's an original Lucas switch it's have more than 3 spade connections & some are common

 

https://www.carbuild...WAaArqIEALw_wcB

 

 

If you have 3 wires:

 

Brown to 1 or 7

 

Red to 4      (6) numbers in brackets will make it work in reverse, if  down was off it'll be up instead.

 

Blue to 8     (2)

Thanks so much for this....

I have replaced the switch as I thought this would be a good place to start. I now have a Lucas switch which is the same as the one in the link that you put. The old switch was also one of these (just not Lucas).

Brown was and is again in 1 - I assume this is power/live

Red was and is again in 4 - I assume this is side lights? As they come on when this is connected!

Blue was loose and I tried in 6 (both with the old switch and now the new switch) and the head lights came/come on - in two of the 3 positions (but no rear lights). And they basically stay on - which is why I think the previous owner disconnected the blue wire.

The reason Blue went to 6, is because a wire from the rev counter was going to 8 (to illuminate the rev counter).

 

So I have now been out and removed the rev counter wire from 8 and put the blue wire there. Brilliant, it all works!! :)

 

Which leaves the question....where should the rev counter wire go to?

[Ethel]

Dash illum is the same circuit as the side lights. You could tap in to it at the fusebox: red/green wire.

[Marc13]

Dash illum is the same circuit as the side lights. You could tap in to it at the fusebox: red/green wire.

Just thinking of keeping it as easy as possible - so there is nowhere at the switch for the rev counter illumination wire to go? 

[Ethel]

I was too,

 

That would be an easy place to tap in downstream of a fuse. Depending how the rest of you instrument illum is wired you may be able to put a piggyback spade connector between an existing bulb & its supply wire.

 

If you're intent on doing it from the switch you'll need to supply an extra fuse & run it off the same terminal as the red wire for the side lights

[Marc13]

I was too,

 

That would be an easy place to tap in downstream of a fuse. Depending how the rest of you instrument illum is wired you may be able to put a piggyback spade connector between an existing bulb & its supply wire.

 

If you're intent on doing it from the switch you'll need to supply an extra fuse & run it off the same terminal as the red wire for the side lights

 Glad I asked the question....sounds complicated off the switch. Would I have to put a new fuse in the fuse box and take the wire to the fuse box terminal where the new fuse is?

 

Or if i go with:

Dash illum is the same circuit as the side lights. You could tap in to it at the fusebox: red/green wire.

See photos of the fuse box - where would I connect the wire from the rev counter?

[Ethel]

Lucky your one remaining free terminal is the one you need 

 

Where are the diy additions to the top fuse going, lighter blue & red spade boots, out of curiosity?

[Marc13]

Thanks Ethel.
So the rev counter wire needs to go to the bottom right on the fuse box?

I'll check the top 2 (light blue and red) tomorrow and let you know.

[Marc13]

Lucky your one remaining free terminal is the one you need

Where are the diy additions to the top fuse going, lighter blue & red spade boots, out of curiosity?

Going from memory here - need to check tomorrow.
The red wire (blue spade) at top left of fuse box, runs to the rev counter (power I assume).
The green, top right, I think runs to the coil (supposed to be white, but I didnt have any white wire). This was done when we were sorting out ballasted/unballasted ignition last year as it was incorrect when I bought the car.

[GraemeC]

Hopefully it’s the other way round - the one top left going to the coil (an unfused ignition live) and the one top right going to Rev counter power feed (a fused ignition live)

Edited by GraemeC, 29 October 2021 - 05:07 AM.

[Marc13]

Hopefully it’s the other way round - the one top left going to the coil (an unfused ignition live) and the one top right going to Rev counter power feed (a fused ignition live)

Correct - it is the other way round. Red wire goes to coil and green goes to the rev counter.

Do I put the rev counter illumination wire to bottom right of fuse box?

[Marc13]

Hopefully it’s the other way round - the one top left going to the coil (an unfused ignition live) and the one top right going to Rev counter power feed (a fused ignition live)

Learning all the time....is that how it works then, unfused goes left side of fuse box and fused go to the right side?