Universal Aux fuse/relay block opinion

[slcfj62]

I have designed a headlight upgrade wiring harness around this fuse/relay block from Bussmann. It could also be configured as a controller for up to 5 Aux cirucuits--fog lights, off road driving lights, radios, refrigerator, etc. The relays are 35 amp. For relay longevity, I wouldn't switch more than about 25 amps, but they are rated at 35.

So here is how it would come configured:

• 5 circuits @ 35 amps max each.
• Battery lead 10 gauge wire with fusible link--3 feet long
• 12 volt or 24 volt relays
• One skinny wire and one fat wire color coded for each circuit
• Each wire 12 inches long--you supply the rest of the wiring and the switch.
• The skinny wire goes to your switch, the fat wire to your load
• Weather tight enclosure
• Spare relay and fuses

Each unit would sell for about $70 plus shipping. What do you think? Anybody interested? If so, I'll order the parts and make a few.

EDIT: Just to avoid confusion, the Aux fuse/relay panel is for 5 Aux circuits and is primarily intended for Cruisers that already have a headlight upgrade harness, but want to control additional auxiliary circuits. The headlight fuse/relay panel uses two or three relays for the headlights (depending on whether you have 2 or 4 headlights). This leaves two or three relays left over for Aux circuits. If that is all you need to control, and you want to upgrade your headlight wiring, then the headlight fuse/relay panel would be sufficient. At present, I have the headlight version developed for the fj62, and I am looking for anyone with an fj60 and an fj80 in the Salt Lake City area that will let me make some measurements so I can build a prototype for each one. I am looking for a mostly stock engine bay and will offer a discount if you decide to buy one of the headlight wiring upgrades when I get them complete.

 

[woytovich]

Sounds interesting... were you including the headlight harness..?

 

[slcfj62]

No, the headlight harness is different. The headlight harness will be more money--all those wires and connectors. But, in addition to running the lights, the headlight harness will also have 2 Aux positions very similar to this aux controller. That's where I got the idea for this.

This auxiliary controller is for someone that already has an upgraded headlight harness and wants to have an additional solution for controlling fog lights, offroad lights, etc.

 

[lrowe_csp]

Very nice setup and I like that idea a lot. I have relays scattered around the engine compartment, and it would be nice to clean it up a little with your setup. It appears that the Bussman box is waterproof or water resistant- is that correct? Will having all of the relays together in one tight compartment cause heat and reliability issues?

 

[slcfj62]

Yes, the box is water resistant/weather tight. It will keep any splashed on water out. If it was submerged for a while, it might leak a little. I recommend mounting it up on top of the wheel well, or on the inner fender wall just below the hood line.

Heat is generated by resistance. Relay contacts have virtually no resistance, so the only heat would be generated by the relay coils which is negligible. Relays are much more heat tolerant than semiconductors. Of more concern would be the heat in the engine compartment. The unit is rated up to 260 degrees Fahrenheit, so unless you mount it right next to the exhaust, it should be fine. I wanted to use circuit breakers instead of fuses, but circuit breakers are only rated at 180 degrees. While I don't expect the internal temperature of the fuse/relay block to normally exceed that, it might on a hot day in the desert, so I will recommend the fuses.