10 replies to this topic

[Mart8V]

Looking to wire in two pairs of driving lamps to the main beam circuit. I have one relay and wiring kit- can I run two sets off that or will I need to buy a second?

I have already upgraded the alternator to compensate.....

Thanks!

[lrostoke]

4 lights shouldn't be a problem off one relay, depends on the wattage of the bulbs.

Most 4 pin 12v relays are rated either 30 or 40 amps.

So say typical 55watt bulbs x 4 = 220 watts total

amp = watts / volts

amps = 220 / 12

amps = 19 (rounded up)

[danie garry]

sorry to steal this 1 but can i wire the fogs on the front of my car the the switch for the rear??

[Mart8V]

4 lights shouldn't be a problem off one relay, depends on the wattage of the bulbs.

Most 4 pin 12v relays are rated either 30 or 40 amps.

So say typical 55watt bulbs x 4 = 220 watts total

amp = watts / volts

amps = 220 / 12

amps = 19 (rounded up)

Lovely! That should save time and effort, not to mention light the road ahead nicely!

They are 55W Ring units so all should fall within limits.

[Dan]

That depends on what the relay is rated to. Many are 30 amp but 20 amp relays are very common, a 20 amp relay would be very close to maximum load with 4 spots and it wouldn't be wise. Also, the wires in the kit are probably only rated to 15 amp or so and won't be up to it.

Danie, technically you have to be able to switch the front and rear fogs seperately because they are needed at different levels of visibility. It would be illegal to have your front fogs on when the rear fogs first become needed. At least that is the case in the UK, I believe most Eire driving law is similar but I'm not certain on the exact details. You can replace the fog switch with a two position switch such as the one for the head lamps (put the fog lens on it) and use it to drive the rear fog only on the first position and the rear fog and a front fog relay on the second position. A tell-tale is not required for the front fogs (again that is UK law). If you mean is the wiring up to it, then it very much is not. You will need a new circuit from the solenoid.

[Mart8V]

That depends on what the relay is rated to. Many are 30 amp but 20 amp relays are very common, a 20 amp relay would be very close to maximum load with 4 spots and it wouldn't be wise. Also, the wires in the kit are probably only rated to 15 amp or so and won't be up to it.

Thanks, Dan. So as long as it is a 30amp relay and similar wiring I should be OK? If wiring is only 15amp I would need two sets of wires from the one 30amp relay on dual connectors, I assume.

[lrostoke]

You will need something like 25amp cable feeding the relay from the battery live

then the feed out of the relay which feeds the driving lights either 2 x 15 amp (one for each pair of lights) cables or a single 25 amp cable feeding all 4

[Burnard]

Just get a 40amp relay from maplin, then you know its not going to blow. it doesnt matter what the relay is rated at so long as its more than the fuse.

[IainR]

Without wish to hi-jack this thread, cable I have come across is sold by core diameter and number of stradns ie.1.0/16, what diameter would be suitable for what amp.

The numpty that had my car before wired 4 spots into the main beam circuit directly (no relay) with cable thick enough for a house ring main - result when you flashed the lights the spots came on and the headlights dimmed to the equivalent of a candle in a brown bottle.

[lrostoke]

Follow this link

gives you size and rating plus they even sell it

http://www.vehicle-w...andardcable.php

[IainR]

Thanks, very useful link.