100/55W H4 Upgrade

[Superman]

I have some of the Bosch "ice cube" relays complete with inline fuses which, I believe, can handle 100 Watts of current (100 Watts / 13 Volts = about 8 Amps). Use of the relays avoids sending all that current through the stalk switch, of course. Here is my question:

Can the rest of my 911SC wiring handle 8 Amps of current? I wonder about the chassis wiring as well as the H4 plugs which connect to the lamps themselves.

[darrin]

I’ve had no issue running these bulbs with stock wiring & sockets after installing relays.

[Trackrash]

I wired my headlights directly to my battery through one of those OE red round relays. I run my headlights most of the time when I am driving and have had no problems for over ten years. And my low beams are 80 watt. So it seems that the wires running to the headlights from the fuses are not causing a problem. The fuse block on the other hand needed some TLC.

It is interesting that the overall wire size on my '71 in some places is at it's limit already. For example I installed higher wattage brake and turn signal bulbs. The stock wiring was not able to handle the extra load and the bulbs were not as bright as the stock equipment bulbs.

Not sure if the SCs upgraded the wire size for the lights or not compared to the older cars.

[RWebb]

with relays, the amps are flowing thru a shorter path, hence there is less resistance than before

the thing to check is whether there is any corrosion in the path, which will greatly increase resistance