No Gauges

[murrayr6]

I have no gauges. Nothing in my instrument panel works. I don't even know where to begin. My main priority is to get the tach, oil pressure, and water temp working in that order. Where should I begin on the tach? I think I should have some wire running to the coil. Is there a way to bypass the original wiring harness and just run a wire from the coil over to the tach?

[baltobernie]

Check fuse #1.

[murrayr6]

Fuse is fine.. Still no tach.

[Nanonevol]

Sure you could wire up a tach but better to get a wiring diagram and figure out what's going on and fix it.

[murrayr6]

The PO of this car said a mouse had gotten into the wiring. At first I did not believe it until I saw the amount of mouse poop in the car. Needless to say the wiring is absolutely screwed on this car. The PO said he did his best with the wiring but ultimately could not get it and the wiring is the reason he sold the car. Most of the original wiring is either in many pieces or is just missing. I have tried my best the wiring and have since gotten the ignition, headlights, wipers, fan, and starter to work. However to get these devices working, I ended up just going around the original wiring harness and put an additional fuse block in. I can try to go through the old wiring harness. Anyone have a picture of the schematic?

[spider2081]

Have you joined Mirafiori.com and accessed their library?? They have the 1977 wire diagram Posted there on page 2 of the electrical.
Do you have voltage on fuse 1 (both top and bottom) when the ignition switch is in the Start or Run positions?
Do you have 3 wires on the bottom terminals at the back side of the fuse. One terminal should have 2 white wires and the other terminal should have a light blue/white wire? I think one of the White wires brings voltage to most of the gauges. there are 2 connectors thatthe gauge harness pass through. The wire wire goes to one of these connectors. At that connector it mates with a yellow/black wires. I think all the gauge power wires are yellow/black in color.

I believe its good to put where you and the car are located in case someone close by is available to assist.

Hope this helps

[maxdog]

I've wasted too many hours putzzing around with many old cars with " modified " or missing wiring .Your wiring was a rodent's banquet , You have no idea if some of the remaining wiring is damaged and could cause a future short or fire ?
I'd bite the bullet , find a year specific wiring diagram , buy a new harness and replace the whole lot . This may seem drastic , but its quite simple just lay out the harness and connect the wires , system by system . Test each system as you go and amaze yourself with your new found skill.
Good luck
Maxdog

[murrayr6]

The more I dig the worse its getting. I am also now just considering buying a new harness. I have search around on the internet and have not found another 1977 wiring harness. Anyone know where I could purchase a whole new wiring harness?

[spider2081]

I am also now just considering buying a new harness

I spent many years working on aircraft that had mice damage to the wiring so I am aware of the damage they can cause. Labor wise I feel you would be better repairing you harness than replacing the entire cars harness. This is especially true if the engine and interior are currently in the car.
There is a physical part of the cars wiring I find is important to focus on in cases like this. Use the wire diagram to determine the color wire and what points it connects. No electrical knowledge is required to physically follow wires or their diagrams. It helps but it is not required. Do keep in mind schematic diagrams and wire diagrams are not necessarily showing physical locations or connections. Example the wire diagrams may show 4 items connected to fuse A. But when you look at fuse A there might be only 3 wires. The other item is connected within the harness.
I think you will have a had time finding a factory new wire harness. Purchasing a used one is certainly an option but chances of it being complete and unmodified is anyone guess.

[baltobernie]

Anyone know where I could purchase a whole new wiring harness?

O.E. Spider wiring harnesses are only available from salvaged cars. The only new harnesses are "Universal" ones from hot-rod companies like Painless, and these require a lot of work to mate with your Spider. Post in "Parts Wanted" for an unmolested 1977 harness. If you get a response, then consider it vs. a wire-by-wire replacement of your mouse nest.

[maxdog]

Try Googling "classic car wiring harness restoration:" . Several companies offer"exact replica" harnesses.You would need to confirm they can supply a Fiat harness
. . I have used Autosparks from the UK who supplied an exact replacement harness for an obscure old English car .
Cheers
Maxdog

[murrayr6]

I have not found any wiring harness on the internet. Like a couple of you guys said, it am just going to go wire by wire finding the destroyed ones. It did not help that the P.O. molested the wiring even more after the mouse did trying to salvage it. I will let you guys know if I run into any problems, i'm sure I will!