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Discussion Starter #1
I see these quotes. Do they still apply to my 87 Spider? Or is that for older cars?

You can gain about 0.4 volts or more if you parallel the red (output) wire from the alternator. The OE wire is too small (resistance and volts drop) for the output of the alternator.
Can't stress enough the importance of paralleling the wire from Alternator B+ to the left side junction box.
If so, I just buy another one from the auto parts store and attach it on top of the old one?

alternatorwire.jpg
 

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Unless you are having charging problems, I wouldn't bother. I can believe that the factory wire drops .4 volts and can believe that a large gauge wire would reduce that drop. But so what? It isn't as if another .4 volt will make your Alfa will go faster.
 

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Discussion Starter #3
I have a few voltage drop issues I am trying to figure out. Headlights, wipers, and heater fan all drop a noticeable amount.

Just one on isn't an issue. Ex: Headlights and heater fan drops it to low and the warning light flickers.

I figure it could help until I find/fix the issues. I have the headlight relay fix from IAP that I might install this weekend.
 

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But Mad North-Northwest
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I see these quotes. Do they still apply to my 87 Spider? Or is that for older cars?
Well, measure it with a voltmeter and find out. If it's really 0.4 volts that's a significant voltage drop and addressing it will make a big improvement.

On my '91 the voltage drop in that wire is negligible, but I believe the factory wire on the S4 is larger gauge.

If so, I just buy another one from the auto parts store and attach it on top of the old one?
Yes. My auto parts store has kits with ~4ga primary wire. Just cut it to length and crimp on some ring ends.
 

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This wire on my 79 spider is at least 4 AWG. A 3 ft length of this wire carrying 100 amps will drop 0.15 volts. A "normal load with your lights, Wiper, Blower and radio on may be 50 amps and then the drop would be 0.075 volts.
 

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But Mad North-Northwest
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I measured the wire and it was about 5.4 mm diameter. That is bigger than 4 gauge. If there is a measurable drop it is more likely to be in the terminations.
 

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I have a few voltage drop issues I am trying to figure out. Headlights, wipers, and heater fan all drop a noticeable amount. Just one on isn't an issue. Ex: Headlights and heater fan drops it to low and the warning light flickers.
As others have written, measure the voltage drop across the alternator-junction box wire under load before concluding that your existing wire is the problem. Another possibility is that your alternator isn't putting out its rated current.

I have the headlight relay fix from IAP that I might install this weekend.
Where does the IAP kit connect to +12v? I would recommend connecting the power feed to the headlight relays (with a fuse of course) directly to the alternator. That will relieve much of the load from your existing alternator-junction box wire.
 

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Discussion Starter #9
I put in another wire just in case. For my peace of mind.

No change. :-(

I guess the next step is to research the ignition switch wires. From the "Voltage drain when A/C is on" thread, that appears to be a possible cause.
 

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Discussion Starter #11
can't hurt, have you relayed your headlights, yet?
No yet. It might have to wait til next weekend.

I found this as a symptom of the ignition switch. This happened to me for the first time a few weeks ago. It took 6 times to get the starter going. Hasn't done it again.

Seems my ignition switch may be a problem. On initial start attempt, once in a while I get all dash lights and fuel pump sound but no cranking. An attempt in a few seconds usually leads to cranking and engine start with no further problem. Sometimes it may take two or three attempts to get the starter to spin and start the car.
I am weak on troubleshooting electrical issues. I need to study up. I have a friend that is starting engineering classes. He said he was taking classing on electrical circuits. Perhaps he can help me.

So you know what I have done.

1. New alternator about 8 months old.
2. New header fan about 1 year old.
3. Cleaned out wiper motor and refurbished entire wiper system 1.5 years ago.
4. Bought used combination stalk to fix lights issue. All lights are working now.
5. Found 70% of grounds and cleaned them up. I need to find every one.

Otherwise, I have fixed most or all my LJet issues. New exhaust parts has the car running quiet. New mounts and some bushings makes the car smooth to drive. Car runs great. Darn electrical issues.

I am not dead in the water. Just working on my list of things to do on the car.
 
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