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MG MGB Technical - Installing Driving Lights

Have purchased two driving lamps for front of my 75 MGB. I have an inline fuse. Can someone give me quick and easy directions on how to connect them? I have a switch that will affix under the dash. Thanks!
Harry

Use a brown wire source on the starter for power. Use a clean part of the chasis for ground.
Did the lights come with a wiring schematic?
power source>fuse>switch>lamp

If you better describe the features you want with the lights (ie. dash indicator, only on when the car is on) let us know on the board so you can be provided the wiring details.
Kimberly

Using Kimberly's sequence tha factory colours would be:-

From unfused power source to fuse - Brown
From fuse to switch - Purple
From switch to driving light - Blue with Yellow stripe
From driving light to earth - Black

In the factory workshop manual the wiring diagrams for early cars show the circuit for optional driving lights.
David Witham

No schematic with lights. Simply on and off with a simple toggle switch. Off when car off.

This is very helpful. David - do you know how I can get a copy of the early wiring diagrams? Is there one posted on line?

Thanks all
Harry

Harry, I'd advise using two fuses, one for the lamps themselves and another in the line to the switch. I'd also install a relay to handle the extra current of the lamps instead of running it through the switch. Connect two wires to contact 7 of the fuse block (brown wires, +12V constant), run both through inline fuses, one larger size to the load contacts of a relay such as the one used for the ignition, and the other one to the coil contact of the relay. From the other load relay connection run to the lights and ground them to the chassis. From the other coil side of the relay run a wire to the switch and then to ground. This will give you both the security of short circuit protection on both wires and for both devices.
Bill Young

Here are two links for wiring up driving lights. The first is for a motorcycle but would also apply for automotive use. The second is about wiring up lights in old British cars.
http://www.gadgetjq.com/wiredrivinglights.htm
http://www.dimebank.com/tech/WiringDrivingLights.html

Clifton
Clifton Gordon

Harry, there is a downloadable PDF of the workshop manual on the forum section of the following website:-

www.octarine-services.co.uk
David Witham

Dan Masters has a complete set of wiring diagrams for the MGB, MGC and MGBV8 at www.advanceautowire.com/ and click on "Stock Schematics".

HTH

Larry
75 BGT
69 C in restoration
58 A
Larry Hallanger

David Witham-

Could you please clarify why two power sources?
My suggestion was to use a brown wire for the power supply, connect the inline fuse that came with the lights, then connect to the switch, and complete the hot side of the circuit at the lamps. Not putting any load on the purple circuit.

Harry-

You will need a relay if you don't want the lights to work when the car is off.

Wiring connections for the relay

Pin 86 - ground
Pin 85 - wire from toggle switch to relay
Pin 30 - power source from brown circuit
Pin 87 - wire from relay to lamps

Wiring connections for the toggle switch

Terminal one - wire from pin 85 on the relay
Terminal two - splice into white wire circuit under the dash, use a bullet connector on the end of the wire to plug into the 4-way sleeve connector that branches the power from the ignition switch to the fuel pump and the fuse box.

Wiring connections for the lamps

one terminal from each lamp connects to pin 87 on the relay.
the other terminal connects to the chasis.

Fuse connections

Install the inline fuse on the wire going from the relay to the lamps as close to the relay as possible.

Wiring diagrams

Wiring diagrams are available at http://www.advanceautowire.com click on stock schematics print yourself a couple of enlarged copies. Make notes on the diagram for yourself showing the extra circuit you just added. Keeping an up to date diagram will help if you have to do any trouble shooting of the electrical system in the future.

Kimberly

Kimberly, I am not saying 2 power sources. What I was doing was providing the standard MG colours for the relevant parts of the circuit. Having had to do work on cars with other peoples mods on them it is useful if they kept to the colour conventions.

Unfused and unswitched = brown
fused but still unswitched = purple

Hence between the fuse and the switch I have recommended using purple wire.

For your information:-
Unfused but switched through the ignition = white
fused and switched through the ignition = green
David Witham

With driving lights a single fuse controlling both lamps isn't an issue like it would be for headlights, so the fuse should be as close to the power source as possible to protect the maximum amount of wiring. This would be close to the solenoid (or wherever the connection to the existing brown circuit is made), not close to the relay, and especially not on the lamps side of the relay.
Paul Hunt 2

I've just installed driving lights on my 78 GT. I just purchased an installation kit from a local car parts shop.. made up of a relay, wiring etc... It came with its own diagram and it took about five minutes to install... Well worth the 10 quid (about $18)...

Good luck!
James

Hi, Driving lights that do not turn off when headlights dipped to low beam would fail Registration of the car here. Fog light are OK not tied to the headlights.I would be using fused power via a relay to the driving lights and picking up battery via highbeam through the switch to operate the relay. Regards Ken
K Stuckey

Ken - that sounds more like old-style spot-lights than 'driving' lights as used on modern cars. The latter are wired by the manufacturer to come on with side or parking lights, they only give a general illumination and are more like old-style fog lights i.e. a low wide beam which doesn't dazzle oncoming drivers.
Paul Hunt 2

Fair enough Fog light used here not in a fog attract a $75 dollar fine. Regards Ken
K Stuckey

It's supped to be a £1000 per light fine here (front and rear), but I've only heard of one case, and judging by the number of people who use them instead of headlights saying 'Look at me, I've got driving lights' the Police aren't bothered.
Paul Hunt 2

This thread was discussed between 17/04/2007 and 23/04/2007

MG MGB Technical index

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