Rewiring 79

[fiatnoob007]

I have a '79 that has some real electrical problems. I plan on rewiring the entire thing, but don't know where to start as far as parts go. Will a universal harness work? If so, is there a brand that works better than others?

[SpiGirl75]

We installed a universal 12 circuit Painless Wiring kit on our '61 Toyota Landcruiser. We also installed a Ron Francis Express Wiring kit on our '37 Ford Pickup. The main difference between the two we used is the Painless kit has the wires already terminated at the panel and the Ron Francis kit we had to terminate the wires at both ends. On our '75 Spider we will definitely go with a Ron Francis kit. The main reason being the wires are bagged separately for each circuit so you can finish one section at a time without feeling overwhelmed by a hundred plus wires coming out of the panel. It worked out to be a much cleaner install for us with the '37 Ford.

[SoFlaFiat]

I used a Painless Harness in my 81 and will tell you, it can be daunting!!



No matter what you use as a starting point, you will have to tap into parts of the old harness such as steering column so don't toss all the old stuff just yet.
You will also want to add some relays as the Painless Harness (not sure about the Ron Francis) only has a horn relay.
Best of luck!!

[76was124]

That looks like allot of work!!

Just out of curiosity, what is so bad with the existing harness (water damage? Insulation crumbling?, PO hacked it up?) that you want to replace the whole thing?

Would it be easier to just run new wires where you have the problems, or are you doing a full restoration?

[btoran]

many electrical problems on our cars can be cured by cleaning up the contacts and grounds. unless the previous owner hacked it up, i'd start there and maybe run new wires only where needed.

[baltobernie]

I used a Painless Harness in my 81 and will tell you, it can be daunting!!

Agreed. It is not a trivial project ...



... but this might help: http://www.dcfiats.org/tech/Installing% ... less-C.pdf

Another possibility is replacing your harness with a known-good one from a salvage car. You don't get the benefits of modern materials and design, but it would be a lot less work. Your intentions for the car should guide you in the choice of repair, replace, or upgrade.

[SoFlaFiat]

Hats off to you Bernie!! It had to be even more "not necessarily painless" with the dash in place! Well done!!

[baltobernie]

Another "shoulda, woulda, coulda" item in my ever-growing list

Painless was interested in making a custom harness for the Spider, but abandoned the idea after realizing they'd need several different versions. There would probably be a market for such a product if our cars were higher priced

[fiatnoob007]

Thanks for all of the input, I will try cleaning the grounds first. I'm not too excited about the project but didn't know how damaged the system had been when the rest of the car rusted so I figured I would redo the whole thing.

[bradartigue]

Thanks for all of the input, I will try cleaning the grounds first. I'm not too excited about the project but didn't know how damaged the system had been when the rest of the car rusted so I figured I would redo the whole thing.

Definately start with testing it and not replacing it. Electrical system replacements rank up there in terms of cars that never see the road again.

[btoran]

what specific electrical problems are you having? chances are folks here have run into, and fixed, them before.

[TX82FIAT]

Anyone that can re-wire a Spider from front to back gets a tip of the hat. The benefits of all new wiring would be great. You could re-route a lot of wires in the engine bay to clean things up. Still, some serious time commitment to get it done and done right. I would only do it is it were required to have a functioning car.

[fiatnoob007]

Here is where I am at with the electrical: I cleaned all of the grounds or at least the majority of them and I am shorting out when I crank the starter. The battery is good. Where is a common place that would cause a short when starting? I haven't started checking fuses yet but will soon.

[AriK]

Ignition switch, but there are no grounds in there to clean. Retrace your steps.

[fiatnoob007]

Thanks, I am having trouble finding the stick fuses that are in the panel under the dash. Do the glass fuses work the same? Also a step-by-step short troubleshooting guide from someone who has gone through it would be much appreciated .