Outer Limits 4x4 Board

So I've got a fully rewired headlight loom with spotlights in my sierra, but at the moment the relays are exposed in the engine bay and I'm getting fed up with replacing them when they fail due to getting water in them.

So here's homebrew my solution:





Fully sealed ABS box, going to use waterproof cable glands for the wire entry/exit. Has four (high-beam, low-beam, spotlight, cooling fan) 30A heavy duty chassis mount relays each individually fused via 4-gang fuse block, wire connection is via 30a screw-terminals. Everything is held in with quick-set epoxy.

Everything can be brought from Jaycar, though I did spot a nice 4-way blade fuse holder at Supercheap, could be used in place of the glass fuse holder...

All thats left for me to do is drill the holes for the cable glands, and mount/wire the thing in the car...

Sounds like a good plan.

man, thats tidy as!

just a quick question.


what was wrong with the factory wiring to need this setup???

built4thrashing wrote:just a quick question.


what was wrong with the factory wiring to need this setup???

factory wiring has no relays at all to start with, and I'm running higher rated headlight bulbs (60w/100w). If I had've left the wiring stock and put in the uprated bulbs I could've had melted wiring, stuffed combination switch, dim lights, etc...

Plus it gives me something to do in my spare time

Cypher wrote:

built4thrashing wrote:just a quick question.


what was wrong with the factory wiring to need this setup???

factory wiring has no relays at all to start with, and I'm running higher rated headlight bulbs (60w/100w). If I had've left the wiring stock and put in the uprated bulbs I could've had melted wiring, stuffed combination switch, dim lights, etc...

Plus it gives me something to do in my spare time

Ditto, i have done the same in mine.

The Jaycar 3AG fuse holders are a POS for high currents.

What happened to mine was that when operating, the plastic in the base softens. As the things are just riveted together this than causes loose connections, which leads to more resistance, more heat and eventually complete failure. You cant solder them as the base also melts.

My driving light fuse eventually melted the rivet right out of the plastic base - very disconcerting at night

Switched to a six way blade style holder ( also Jaycar but a newer addition to their range ) and never looked back.

Do yourself a favor - fix it before you go too much further.

PS its also easier not to have to carry different types of spare fuse.