I've been wanting to put my Scorpion's headlights on relays ever since I got it. They've been not very bright and I worry incessantly about the ignition and headlight switches. Finally today I tackled it, after a few false starts.
First I studied the car and the Scorpion wiring diagrams from the Lancisti site. Like many older Fiats, the car's wiring is thick enough, but the switchgear is delicate. Also like many Fiats, on the Scorpion the power for the headlights comes from the battery, through the ignition switch, through the headlight switch, through the fuse box and finally to the lights themselves. This means the full load of the headlight circuit is running through the old, delicate switches and many connectors.
In my Spider relay kits I run a new power wire from the alternator to a set of NAPA 192D relays and insert the relay harness into the stock wiring at a wire connection along the fender.
Bob Brown's insertable X1/9 headlight relay kit installs 4 relays near the headlights themselves, and use a single power wire that branches to both headlight pod areas. The original wiring is used to trigger the relays. It's a good setup.
The Scorpion's headlight recesses and connectors are only accessible by removing the headlight. Also, the existing wiring is hard to get to, and has no insertion points in the run. The stock wiring is 12g, so rather than install a substitute wire harness in the car, especially given the difficulty of access, I decided just to relay the circuits in the fuse box area.
I ran a new fused 10g wire from the (+) post of the battery to the fuse box area, where is splits into two 12g wires, one for each relay. I like the 192D relays because they have 2 "87" outputs, ideal for pairs of lights.
I removed the grey, grey w/black stripe, green, and green w/black stripe wire connectors from the back of fuses 3-6. These wires go to the headlights, the green ones are high beam and the grey ones are low beam, with the plain ones to one side and the black-striped ones to the other side. I backed the connectors out of their little white covers and inserted them into the relay sockets' (87) terminals, grey to one relay and green to the other. Then I ran small trigger wires to fuse 4 for the high beams, and fuse 5 for the low beams, using the white covers that I removed from the green and grey wires. There is a smaller green w/black stripe wire on fuse 3 that goes to the high beam indicator on the dash. This way the original fuses protect the trigger wires and indicator bulb wire, except for fuse 6 which is unused.
Then I grounded the relay circuits with small black wires in a ring terminal where the stock wiring grounds are also grounded.
This pic shows the relays, relay trigger, ground and power wires:
This is the back side of the relays showing the stock grey and green wires inserted into the sockets:
Here's the relays tucked into their new home in the space above the wiring:
A quick test showed normal function and once it gets dark I'll test them out for brightness. Once I know they're working well I'll probably go for higher wattage bulbs in my H4 Hella headlights.
First I studied the car and the Scorpion wiring diagrams from the Lancisti site. Like many older Fiats, the car's wiring is thick enough, but the switchgear is delicate. Also like many Fiats, on the Scorpion the power for the headlights comes from the battery, through the ignition switch, through the headlight switch, through the fuse box and finally to the lights themselves. This means the full load of the headlight circuit is running through the old, delicate switches and many connectors.
In my Spider relay kits I run a new power wire from the alternator to a set of NAPA 192D relays and insert the relay harness into the stock wiring at a wire connection along the fender.
Bob Brown's insertable X1/9 headlight relay kit installs 4 relays near the headlights themselves, and use a single power wire that branches to both headlight pod areas. The original wiring is used to trigger the relays. It's a good setup.
The Scorpion's headlight recesses and connectors are only accessible by removing the headlight. Also, the existing wiring is hard to get to, and has no insertion points in the run. The stock wiring is 12g, so rather than install a substitute wire harness in the car, especially given the difficulty of access, I decided just to relay the circuits in the fuse box area.
I ran a new fused 10g wire from the (+) post of the battery to the fuse box area, where is splits into two 12g wires, one for each relay. I like the 192D relays because they have 2 "87" outputs, ideal for pairs of lights.
I removed the grey, grey w/black stripe, green, and green w/black stripe wire connectors from the back of fuses 3-6. These wires go to the headlights, the green ones are high beam and the grey ones are low beam, with the plain ones to one side and the black-striped ones to the other side. I backed the connectors out of their little white covers and inserted them into the relay sockets' (87) terminals, grey to one relay and green to the other. Then I ran small trigger wires to fuse 4 for the high beams, and fuse 5 for the low beams, using the white covers that I removed from the green and grey wires. There is a smaller green w/black stripe wire on fuse 3 that goes to the high beam indicator on the dash. This way the original fuses protect the trigger wires and indicator bulb wire, except for fuse 6 which is unused.
Then I grounded the relay circuits with small black wires in a ring terminal where the stock wiring grounds are also grounded.
This pic shows the relays, relay trigger, ground and power wires:
This is the back side of the relays showing the stock grey and green wires inserted into the sockets:
Here's the relays tucked into their new home in the space above the wiring:
A quick test showed normal function and once it gets dark I'll test them out for brightness. Once I know they're working well I'll probably go for higher wattage bulbs in my H4 Hella headlights.
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