I need a new harness

[TwinFast]

I spend a lot of time fixing my harness. Just when everything seems good, something goes wrong. So I'm considering buying a new harness. Is there any seller that sells a complete harness ready to install for a 1977/78 spider ?

[TX82FIAT]

I have not seen a new plug and play wiring harness for any year Spider. There are used ones available online but no guarantee that will solve anything. If you search Painless Wiring Harness it may get you started in a laborious direction. I seem to recall a post where the owner of FI Spider 2000 meticulously photographed and labeled each and every connection on the wiring harness and sub harnesses before creating his own harness with a painless wiring kit. It looked like an incredible amount of work but in the end may be worth it to eliminate the gremlins that occur occasionally. At one point I spent about two weeks tracking down a hot to ground where it appeared the factory had pushed a piece of metal through a wire loom under the dash to attach it to a support rail. Never really sure the factory wiring diagram will equal the actual colors used for your circuits when installed at the factory.

[TwinFast]

I have not seen a new plug and play wiring harness for any year Spider. There are used ones available online but no guarantee that will solve anything. If you search Painless Wiring Harness it may get you started in a laborious direction. I seem to recall a post where the owner of FI Spider 2000 meticulously photographed and labeled each and every connection on the wiring harness and sub harnesses before creating his own harness with a painless wiring kit. It looked like an incredible amount of work but in the end may be worth it to eliminate the gremlins that occur occasionally. At one point I spent about two weeks tracking down a hot to ground where it appeared the factory had pushed a piece of metal through a wire loom under the dash to attach it to a support rail. Never really sure the factory wiring diagram will equal the actual colors used for your circuits when installed at the factory.

Thanks for your answer.
I finally found a used one sold by midwest-bayless ... I hope it'll work for me. I know it's not a direct plug and play. My car is a 78 Californian model imported into France. When I got it, it comes with a lot of "gremlins" as you say. I have already "cleaned" my current harness to make it easier by removing all the unnecessary stuff (seat belt buzzer, the useless circuit breaker- antipollution system etc ...)

[spider2081]

My car is a 78 Californian model imported into France

Are you located in France?
My personal opinion is its easier to repair an existing harness than it is to install a different one. I think there are harness changes mid year 77/78 model year. so another harness may not be identical. Its usually the terminals at the end of wires that are troublesome not the wire itself. Also Fiat Harnesses are in sections that plug together. You may find it easier to replace only a section of the harness not the entire assembly. the build date on the drivers door jam might give a hint as to what wire diagram is closest to your cars wiring. For some Spiders a 77 wire diagram might be closer to what in the car. The library in Mirafiori.com has a Fiat publication " Spider 2000 Electrical Diagnostic Manual 1980-1981" I think you would find this Manual very helpful.

[Yadkin]

I replaced the entire harness on my 74 with a basic Painless kit. Yeah, a lot of work. But the factory fuse block (ten fuses plus all the add-ons) was nearly melted.