Stock rover relay explanation

[SeriesShorty]

All of the relays listed in my stock circuit diagram show connections for:
c1, c2, w1, w2

Are they like a typical 4 prong Bosch type of relay? If so, what Rover designation matches the Bosch designation. 86, 87, 30, 85

Thanks!

[scatterling]

30 - c1
85 - w1
86 - w2 - earth
87 - c2

hope it helps

[SeriesShorty]

Thanks Neil, that does help!

I'm trying to figure out how to wire in the brake switch and I'm assuming a relay would be involved. The original circuit diagram shows it going through a Lucas relay.

Anyone have any suggestions on how to wire this up since this is a complete rewire using a Painless style harness?

85 to Fuse block
86 to Brake switch
30 to Brake lights
87 to Ground

????

[greenmeanie]

You shouldn't need a relay for the brake lights. There just isn't enough current draw to warrant it.

Take the wire from the fuse block and attach it to one terminal of the brake light switch, run another wire from the terminal back to the brake lights and you're done. The switch only connects once the brake pedal is depressed allowing the switch plunger to move downwards.

[SeriesShorty]

Thanks GM. I think where I am getting confused is that my brake switch has 2 terminals on it. One to the wiring harness and one grounded to the footwell. ?? Help me Obi Wan! :p

[greenmeanie]

You take a wire for power from the fuse block and run it to the first terminal on your switch. It can be either one. Run a second wire from other terminal on the switch to tha back of the truck where you split it to the two brake lights brake lights. Ground for the circuit is provided by the black earth wire on each light fitting.

In this method you always have a hot wire to one side of the switch. When you press the brake pedal the switch closes and the rest of the circuit has power and the brake lights glow. This is how LR did it on the 101 and involves the least wiring.

Your current set up sounds like they have the power lead from the fuse block going to a relay (85)and then to the brake lights at the back of the truck (30). The relay is merely a heavy duty switch. The brake light switch on your pedal tower now acts as a low power circuit to opearte the relay. You will have a power wire, hopefully from the fuse block going to the relay (86) and then the ground wire (30) goes to one terminal on the brake light switch with the other terminal merely grounded on the body.

Now for the low power realy operation circuit you have a hot wire running through the relay to one terminal of the brake light switch. As long as the switch is open no current will flow and the relay will not close so no brake lights. When the pedal is pressed, the brake light switch closes connecting the circuit to ground, the relay switches and your brake lights come on.

Its is functional and may increase the life of the brake light switch but it is really much more complicated than necessary for the current draw from two brake light bulbs. The first method works well, is simpler and cheaper.

[SeriesShorty]

You take a wire for power from the fuse block and run it to the first terminal on your switch. It can be either one. Run a second wire from other terminal on the switch to tha back of the truck where you split it to the two brake lights brake lights. Ground for the circuit is provided by the black earth wire on each light fitting.


I like it, simple and cheap like me. :thumb-up: Your detailed explaination was greatly appreciated. I'd really love to get this baby back on the road by september for the British Car Show. Wish me luck!