Mark 1 to Mk2 Wiring Change: Oil Warning Light

[V Mad]

I really like the Mk1 cars, and on my car I am trying to keep many of the Mk1 features but I feel that some things just have to be changed for improvements sake.

One of them is the oil and brake fail warning light circuit. The Mk1 system has the oil and brake fail bulbs connected in series which means that the green oil light glows dimly because the bulb does not get the full 12 volts. Also when the brake fail light comes on, the oil warning lamp cannot light. Its just a confusing and bad design.

The Mk2 is much better because the oil light works independantly of the brake lights and works to full brightness. The brake fail light is now connected to the hand brake circuit so that it lights up when handbrake is applied; this is done to test the bulb.

I am going to modify mine and this involves a simple mod to the wiring just behind the warning light cluster (one cut and two new links). Its quite simple but if anyone wants me to post the circuit diagram let me know and I will get it scanned in.

[mallardstag]

Hi Chris,

Sounds like a worthwhile mod. Yes please I'd like to see a copy of your modified wiring diagram.

Simon

[Princejohny]

I'd like to see modified wiring diag too, please Chris.
I had my white Stag cluster (Mk 1) out last month because every light is dim compared to my Mk 2. Added an extra earth but still not very bright. The oil light cannot be seen when the covers on.
Cheers Johny

[V Mad]

Just tried it and it works fine. Takes about 10mins to do. You will need a couple of Scotchlock connectors, pliers and wire cutters.
WIRING MOD BRAKE OIL WARNING.jpg

[mallardstag]

Thanks Chris,

Thanks for the circuit diagram, that looks a worthwhile mod.

Am I right in thinking that either the handbrake or the PDWA will now light both the 'brake fail' and 'handbrake' lights? If so then replacing the wire link between the handbrake and PDWA switches with a diode will mean that the PDWA will only illuminate the 'brake fail' lamp, but the handbrake will test both lamps when applied.

Suitable diodes are available here.

WIRING MOD BRAKE OIL WARNING.jpg
Simon.

[V Mad]

Am I right in thinking that either the handbrake or the PDWA will now light both the 'brake fail' and 'handbrake' lights? Simon.

Yes, thats correct, but I dont see any disadvantage in that. Is it worth bothering with the diode (which would work if you want to do it)?

[Firept]

Chris.
I am surprised at you.
Please not Scotch blocks they're for bodger's and tow-bar installers not professionals like you.
Bullet crimps or solder and black joiners please.

Paul.

[Firept]

Oh great idea by the way thanks.