Brighter Headlights and Dash Lights (easy mod)

[nelsonj]

The other day my dash board lights went out while driving at night. I started playing around with my wiring and eventually my headlights stopped working. As I tracked things down, it turned out that power for the lights was not making it from the ignition switch to the light switch. I performed the following "mod" and now my headlights and my dash board lights not only work, but they're MUCH brighter than before.

1) I cut about 2ft from an AC cord from a non-functional cable box. Inside the cord are two insulated conductors. I stripped about 1 inch of insulation from each conductor and then twisted the exposed copper wires together. I did this on both sides of the cord so I now had a single, well insulated conductor capable of flowing high currents. Any cord will work (like from a lamp), but try to get as much conductor as possible (thickest volume of wire with the insulation removed).

2) At the base of the ignition switch (where you put your car key) there is a connector box. On my 78 the light blue wire runs power from the ignition to the light switch. I basically forced my new conductor into the light blue slot of the box, ensuring I had a solid and tight electrical and physical connection.

3) Next, I removed my dash wood to access the headlight switch. I removed the switch from the dash to gain access to its electrical wiring connection.

4) After running my new conductor up from the ignition and through the back of the dash, I then crammed the other end of my new conductor into the light blue (and brown) slot of the light switch connection box. I then put everything back together.

This "jumper" provides a low resistance electrical path to feed power from the ignition to the light switch. In turn, the dash lights and the head lights see much closer to the full 12V from the battery. In my case, this made a very big difference and everything is much brighter, but results will vary depending on the shape of your wires, but in any case it will "do no harm" not matter what state of brightness you have.

Anyway, the mod is an easy thing to try if your dash lights and headlights are dim. Good luck.

[So Cal Mark]

you'll find the headlight switch doesn't last very long with all of that amperage running through it. The best upgrade is to use the headlight switch to control a relay to power the lights

[htchevyii]

I used a modified IAP relay kit, with excellent results. Instead of using the provided headlamp plugs, I used bullet connectors connected to the stock wiring. None of the factory harness was cut and the light are as bright as a new car.

[baltobernie]

you'll find the headlight switch doesn't last very long with all of that amperage running through it. The best upgrade is to use the headlight switch to control a relay to power the lights

Then you will discover that all of your other electrical accessories; wipers, heater/defroster fan, etc. will work better with full voltage, so you'll begin installing relays everywhere. But even then, you still have crappy turn signals and hazard flashers, and the slightest electrical problem will have you troubleshooting the original circuit and switch, the aftermarket relay and its fuse, and all those connectors. Why not save yourself all this time, expense and grief, and just rip out all the Fiat wiring and install a modern American harness and fuse block? Not only are they color-coded, but the actual function of the circuit is labeled on each wire continually along its length.

[digitech]

Do you have a source for this wiring harness?

[JammerX19]

Do you have a source for this wiring harness?

International Auto Parts sells it.

[baltobernie]

IAP and others sell a relay kit for Spider headlamps. Nobody makes a harness for the entire car. You can easily adapt a "universal" harness like this:
http://dcfiats.org/tech/Installing%20th ... less-C.pdf

[So Cal Mark]

haha, "easily adapt". We just did a painless conversion on a resto-mod we're doing. It's a pretty big undertaking to remove the entire harness and install the new setup. Converting everything to relays and adapting the universal harness to the Fiat ignition, turn signal switch, etc

[fiat218]

IAP and others sell a relay kit for Spider headlamps. Nobody makes a harness for the entire car. You can easily adapt a "universal" harness like this:
http://dcfiats.org/tech/Installing%20th ... less-C.pdf

I don't see how that be easy

[So Cal Mark]

we used a Painless harness, and it's a big undertaking, although in theory it sounds so simple

[nelsonj]

My jumper took about 1hr. A new headlight switch is only $15 if it burns out, and again can be replaced in less than an hour. Plus, you don't add any undocumented complexity to the existing setup.

Life is a series of compromises, and the bang-for-the-buck ratio of adding a single jumper will be hard to beat. (But I do like the idea of adding relays some day, but right now I don't see any reason to do it.)

[baltobernie]

The process took me about 40 hours, including the "learning curve", sourcing materials, e-mails with techs, and documenting the procedure for the rest of you. I'd estimate 20 hours now. It's not hard work, but one must be meticulous.

I know it's just me, but how somebody could spend a thousand dollars on wheels and tires, or a hundred hours on body work, but not sort out the electrics for half those amounts puzzles me.

[majicwrench]

No need to change out the Fiat wiring, it works. Changing wiring harness a serious pain on any car. A few modification might be fun, but basicly it WORKS. And guess what, it is already color coded, look in any wiring diagram. Some very smart people designed the system.
Keith

[81SPIDERMATT]

No need to change out the Fiat wiring, it works. Changing wiring harness a serious pain on any car. A few modification might be fun, but basicly it WORKS. And guess what, it is already color coded, look in any wiring diagram. Some very smart people designed the system.
Keith

wisdom

[RRoller123]

fyi: My updated ground pod system (engine compartment, both fenders). You can effectively attack the weakpoints without redoing everything. Works perfectly so far (about 5 months) Fingers remain crossed.