In-Line fuse from alternator?

Gotta love that wiring . . .
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markintheair
Posts: 56
Joined: Fri Oct 12, 2012 7:44 am
Your car is a: Fiat 124 Spider 81 FI - Corsa Rosso
Location: The Netherlands

In-Line fuse from alternator?

Post by markintheair »

Hi y’all,

I’m restoring my EFI 1981 Spider and I’m coming across some interesting wiring…
I can’t seem to find anything about this in Brad Artigue’s Wiring Diagrams, nor on the forum. It seems there is an in-line 8A fuse going from my alternator directly to the following connector block:

https://imgur.com/hxu2aSq

Can anyone help me identify this block/relay?

My other question: why would there be a fuse right there? Does anyone have any experience with this?
The fuse can be seen in the following pic:

https://imgur.com/mRNXGHu

There’s quite a thick red wire going from there to the other side of the engine compartment, where there’s also a black square block. No idea what this wire is or does, as I also can’t find it on the diagrams.

Hopefully somebody can enlighten me, thanks! :D
Only the fool looks at a finger that points at the sky.
'81 FI Spider 2000
spider2081
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Your car is a: 1981 Spider 2000
Location: Wallingford,CT

Re: In-Line fuse from alternator?

Post by spider2081 »

I'm pretty sure the "Cube" is a Bosch style relay. A Previous owner added it to control something. The inline fuse being only 8 amps sort of indicates it isn't the radiator coolant fan or the starter solenoid. Usually they are fused closer to 16 amps.
The relay terminals are numbered. 85 and 86 are the relay coil. terminals 30 and 87 are the relays contacts. Most connect the power to terminal 30 so I would expect the fuse to be connected there. The load (what ever the relay is turning on) would be connected to terminal 87. Possible someone added fog lights or something like that can you see where the wire on terminal 87 connects at tits other end??
spider2081
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Your car is a: 1981 Spider 2000
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Re: In-Line fuse from alternator?

Post by spider2081 »

Sent you a private message on this site.
AlexD
Posts: 51
Joined: Mon Sep 07, 2020 10:38 am
Your car is a: 1980 Spider 2000

Re: In-Line fuse from alternator?

Post by AlexD »

I agree with spider2081 that it's likely a relay set-up for lighting considering the capacity of the inline fuse and the fact that there are connected relays on both sides of the engine bay. I'd wager on fog lights if your car has them otherwise I'd lean towards headlights. Can you trace the wiring from the relay towards the front of the car? I'd expect to see a few more wires if it were for the headlights but am not as skilled as those who have configured their own relays - I cheat and go with the ready-made rigs from our supporting vendors (AR/Vick).

Knowing whether or not you have any add-on equipment that wasn't stock/standard would help identify what this could be.

As for the inline fuse, it's there to protect the relays/circuit since you're drawing power straight from the alternator (which is getting it's power straight from the battery by way of the starter) instead of passing through the fuse panel like most of the other circuits.
markintheair
Posts: 56
Joined: Fri Oct 12, 2012 7:44 am
Your car is a: Fiat 124 Spider 81 FI - Corsa Rosso
Location: The Netherlands

Re: In-Line fuse from alternator?

Post by markintheair »

Thanks for the replies so far!

I've traced the wires and it goes back to the grey cable for the low/high beam. Maybe at some point in the past the PO indeed installed fog lights or something, I've never had them on there. As the setup is now, the relays and extra cables serve no function whatsover. I've removed it all and it's not coming back in the rebuild.

I'm aiming to restoring the wiring as original as possible, and these additional cables were a mess from the moment I've had the car. Thanks again!
Only the fool looks at a finger that points at the sky.
'81 FI Spider 2000
markintheair
Posts: 56
Joined: Fri Oct 12, 2012 7:44 am
Your car is a: Fiat 124 Spider 81 FI - Corsa Rosso
Location: The Netherlands

Re: In-Line fuse from alternator?

Post by markintheair »

I've done some more digging and it seems the PO might have tried to do something that's described here:

http://www.danielsternlighting.com/tech ... elays.html

I've found this link on the mirafiori knowledge base, quite an interesting read! I guess the PO cheaped out a bit by using piggyback connectors instead of running dual fused wires.

The link to the article in the KB on mirafiori:
https://www.mirafiori.com/faq/content/relays.htm
Only the fool looks at a finger that points at the sky.
'81 FI Spider 2000
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