Red starter wire

[GreenGrizz77]

Hello all it’s my weekend so I getting back into the beast in all the wiring diagrams I can find the starter should have the battery cable and then just the three that go back to the ignition lock the black brown and red. I have an extra red and both red wires run up to one of the relays. I’ve got 8 relays total in that pack in the drivers side engine bay and not sure what most of them do as I can’t find a diagram that includes them. I’m taking all of my smog equipment out and planning on eliminating any relays I don’t need.

So I guess my question is does anyone know why I would have 2 red wires on my starter and should I run the red that is supposed to be there back to the ignition rather than the relay?

[GreenGrizz77]

The relay is a 90050 12v 5 prong if that helps

[18Fiatsandcounting]

I'm guessing someone added that second red wire, as the stock starter motor should have only the thick red, brown, and black wires as you noted. And the beefy cable to the battery. The stock red wire operates the solenoid on the starter, so it's energized when the ignition switch is turned to the start position (but not energized in the run position).

Perhaps a relay was added to drive the fuel pump, if you have an electric one?

-Bryan

[GreenGrizz77]

I don’t believe it’s for a fuel pump I has it’s original one the PO installed an ac but the relays look just as old as the car except for the extra one for the ac that was wired in strange I wish I could post pics on here

[GreenGrizz77]

I should’ve added that both lead into the relay and 4 thinner gauge wires lead out 2 white with black stripe 1 blue with yellow stripe and 1 blue with red stripe

[spider2081]

then just the three that go back to the ignition lock the black brown and red.

I think the brown wire from the starter solenoid battery cable stud feeds "hot all the time power" to the ignition switch terminal 30. The black wire on the same battery post connects the alternator to the battery and the red wire with the push female spade connector activates the starter solenoid when the ignition switch is in the "start" position.
Are you saying there are 2 additional red wires with ring terminals on the battery + stud of the starter solenoid? Do these red wires look factory original?
I think there is a second black wire on the alternators output terminal that also feed "hot all the time" power to the ignition switch terminal 30/1

My last question, with the drivers door open on the cars door jam there is a white plastic tag. This tag shows the cars build date. What is that date?

[GreenGrizz77]

No there are 2 red wires total one is connected in with the brown wire and the other is the one with the female connector and they both lead to the same relay while the brown and black run to the firewall It’s all old but the ends look original or done by first owner but the wires have been cut and “fixed” and you can tell where there’s some newer wire

And I will get that date later for sure but if memory serves me right I think it was March of 75

[GreenGrizz77]

01*75 is the stamp so I was wrong she’s a January baby. Also side note I know she’s a cs1 but after taking the dash out I’ve got a heater core with bs1 written on it so I guess they had a few of those left over in 75 still

[spider2081]

I believe 01/75 would be a 1975 Spider.
I looked through my 1974,75,76 wire diagrams and none show the wire configuration you mention. I am assuming a previous owner modified your cars wiring. I'm guessing they installed a "start" relay similar to what Fiat did with the automatic transmission cars. Being as the wire diagrams don't show what you have I'll continue to guess. The pins on a Bosch relay often are as follows. 85 and 86 are the relay's coil and they activate the relay.
Pins 30, 87, and 87a are the relay contacts. The pin numbers can be seen looking at the bottom of the relay near the relays pins.
The relays coil pins are not polarity conscious so they can be connected either way. I expect one would have the white/black wire and the other would have a wire that traces back to terminal 50 on the ignition switch.
The red wire from the starter solenoids battery stud would connect to relay terminal 30, the movable contact that switches from 87a to 87 when the relay is energized. Relay terminal 87 would connect to the starter solenoids only spade terminal (red wire with push on connector)
terminal 87a if the relay has an 87a is not used.
Hope this is some help