starter help

Gotta love that wiring . . .
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geospider
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Your car is a: 1979 Spider 2000
Location: concord, ca

starter help

Postby geospider » Sun Oct 01, 2017 8:36 pm

OK, So I have read many posts about installing the relay for the starter. I am just trying to work through all the wires.
'79
Image
wires: 1 huge green, then a darker green and brown.
there is a brown wire at my battery, but I thought the factory "fix" was sending this to the other #30 terminal on the ignition.

back to the relay:
I would assume the red is the "switch" from the ignition? Goes to #85 on relay then #87 to where the red was attached
86 is ground
#30 on relay to solenoid through a fuse.

I guess what confuses me, is, (besides the fact that this electrical stuff confuses me) if power comes directly from the battery, how much and when does it go through the ignition? I thought I had read something about taking power from the alternator post.

old posts don;t maintain the photos which would help a lot.

maybe I don;t need to know that to set this up.

confused Geo

DieselSpider
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Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: starter help

Postby DieselSpider » Sat Oct 07, 2017 8:47 am

The red wire currently powers a fairly high powered electromagnet on the starter that shifts it into gear and then closes the contacts which sent power to the starter motor.

Your goal is to have that red wire now plugged into the electromagnet coil on a very low draw 40 amp relay so it can take power from the big green wire on the starter using an inline 15 amp fuse and route it through its contacts back to the terminal where the red wire was originally connected on the starter.

A single throw normally open generic 40 amp automotive lighting relay that sells most everywhere for about $5.50 will do just fine for this.
Image

Clean up the stud along with the wire terminals, washer and nut you removed from the input power stud on the starter while your at it.

ORFORD2004
Posts: 1096
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: starter help

Postby ORFORD2004 » Sat Oct 07, 2017 9:31 am

85: + from the switch
86: GND
30: + from the fuse box
87: + to the starter
87a: not in use

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geospider
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Your car is a: 1979 Spider 2000
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Re: starter help

Postby geospider » Sat Oct 07, 2017 11:36 am

Thanks guys. worked it all out yest. Sometimes when you just stare at it a while, you can start to see how the current goes and it makes sense.
would a 30 amp be enough?

DieselSpider
Posts: 2130
Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: starter help

Postby DieselSpider » Sun Oct 08, 2017 9:56 pm

Its only a 10 to 15 amp draw from the solenoid so 30 should do just fine. I like to use the universal lighting relays since those are rated for constant duty while others are rated to carry the specified load only momentarily. The added plus to using lighting relays is that as you isolate the loads from other items such as head lamps you will be using the same model of relay and will have one universal relay to stock up on as a replacement.

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geospider
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Your car is a: 1979 Spider 2000
Location: concord, ca

Re: starter help

Postby geospider » Mon Oct 09, 2017 9:48 pm

Thanks.
I'll leave the 30 A.
I'll let you all know how it works when I finally put the redone head back on.
the sad part will be putting the Calif smog mani and carb on when I have a perfectly good flat lane and 32/36 weber.

maybe a switch every 2 years is worth the trouble


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