Alternator Wiring

[500stroker]

I have a 66 Satellite with stock wiring.
I will be adding cooling fans which will draw about 50 amps.
I dont have the money to upgrade to a higher output alternator and rewire the car.
The output wire coming off the alternator was butchered by a prior owner and showed signs of being hot at one point in time, these has been corrected and now is in good shape.
I know putting a big fan load on the stock alt. and wiring is not the best but its all I got to work with.
Can I simply add a new 8 gauge wire from the alternator directly to the positive side of the battery while keeping the stock wiring in place? My thought here is to take some of the load off the old wiring and the factory dashboard ammeter.
Will adding the wire drain the battery when the car is not in use?
Am I on the right track or just nuts.

 

[Mogre]

I used #8 gage from the alternator to the starter relay with the last 6 inches of #12 gage as a fusible link. This will take the load off the ammeter and the bulk head connector.

 

[dpstark2]

If you run an 8 awg wire directly from the alternator output to your battery, your battery will still charge and will not drain with the car off. However, you are not addressing the fact that you are adding fans. Your stock alternator (if it is stock) isn't going to support your 50A fans and stock electrical system. It's only rated (most likely) at 45-60A. When your fans turn on, your alternator won't keep up and the battery will drain. When they turn off, it will recharge the battery, but you are placing a load on your alternator and battery that was never intended. It won't work well if it works at all.

Finally, if you wire directly to your battery, you will be bypassing your ammeter. You should include a fuse or fusible link in your 8 awg wire. You will want to remove or otherwise terminate the original wire that connected to your alternator and ran to the bulkhead, eventually going to the ammeter. In your case, you can potentially leave that wire connected to the ammeter, with the ammeter essentially in parallel with the new 8 awg wire, but if you buy a higher output alternator you will need to bypass the ammeter as described.

Your fans should be wired directly to the battery through their own breaker or fuses and a relay. Do not wire them into existing circuits.

 

[65 3 times]

Yes Yes Yes.... Wire #1 Alt #2 Relay #4 then Fan...

- - - Updated - - -

#3 would be have a beer ..

 

[500stroker]

If you run an 8 awg wire directly from the alternator output to your battery, your battery will still charge and will not drain with the car off. However, you are not addressing the fact that you are adding fans. Your stock alternator (if it is stock) isn't going to support your 50A fans and stock electrical system. It's only rated (most likely) at 45-60A. When your fans turn on, your alternator won't keep up and the battery will drain. When they turn off, it will recharge the battery, but you are placing a load on your alternator and battery that was never intended. It won't work well if it works at all.

Finally, if you wire directly to your battery, you will be bypassing your ammeter. You should include a fuse or fusible link in your 8 awg wire. You will want to remove or otherwise terminate the original wire that connected to your alternator and ran to the bulkhead, eventually going to the ammeter. In your case, you can potentially leave that wire connected to the ammeter, with the ammeter essentially in parallel with the new 8 awg wire, but if you buy a higher output alternator you will need to bypass the ammeter as described.

Your fans should be wired directly to the battery through their own breaker or fuses and a relay. Do not wire them into existing circuits.

I dislike using fusible links as they tend to leave you on the side of the road if they burn thru.
I am using the stock 60 amp alt., can I just use a 60 amp circuit breaker?

 

[ilm65]

If you run an 8 awg wire directly from the alternator output to your battery, your battery will still charge and will not drain with the car off. However, you are not addressing the fact that you are adding fans. Your stock alternator (if it is stock) isn't going to support your 50A fans and stock electrical system. It's only rated (most likely) at 45-60A. When your fans turn on, your alternator won't keep up and the battery will drain. When they turn off, it will recharge the battery, but you are placing a load on your alternator and battery that was never intended. It won't work well if it works at all.

Finally, if you wire directly to your battery, you will be bypassing your ammeter. You should include a fuse or fusible link in your 8 awg wire. You will want to remove or otherwise terminate the original wire that connected to your alternator and ran to the bulkhead, eventually going to the ammeter. In your case, you can potentially leave that wire connected to the ammeter, with the ammeter essentially in parallel with the new 8 awg wire, but if you buy a higher output alternator you will need to bypass the ammeter as described.

Your fans should be wired directly to the battery through their own breaker or fuses and a relay. Do not wire them into existing circuits.

500stroker, I faced the same dilemma with my two 23 amp fans in my Be Cool set up. I initially ran them off of a separate Painless relay using the stock alternator. I couldn't keep the battery charged and was getting jumped just to get home from local cruises. Went with a 100 amp Tuff Stuff alternator and NO PROBLEMS! Also, you MUST upgrade the wiring to 8 gauge (solid--not stranded) and MUST use a 12 gauge fusible link--don't be foolish and jeopardize your 50 year old electrical system. Visit Mad Electrics website--tons of good useful and understandable information on this conversion--also, do yourself a favor and bypass your ammeter gauge (install a voltmeter) even with the stock alternator, you're running too much current through the present gauge--again, read what Mad Electric has to say. Good luck; Bob

 

[65 3 times]

One of the nice things about electrical current is that it is consistent. It follows rules very well. Listen to ilm65. 60 amp + ignition + headlamps = dead battery. It will happen every time.
Nice Ply ilm65. Could we see more pics. DCR

 

[ilm65]

Hi DCR and thanks for the compliment. I hate to take up 500stroker's thread space so I'll humbly suggest hitting the "View photos..." statement on my avatar listing--with the photos, there's also an explanation of what I've done with the car and why. Again, thanks! Bob

 

[69f6bee]

How about a picture of that alternator? i am looking at doing the same thing and have already bypassed the ammeter gauge. Don't want to burn up the dash wiring. Very beautiful 65 btw.

 

[dpstark2]

The Tuff Stuff 100A unit (or Power Master) are nice in that they fit directly. They are quite expensive- you can get smaller more efficient units that fit with a bit fabrication. If that's not in your future, then some companies make kits to fit smaller Denso alternators (100A-120A units) in the stock location. Whichever route you go, I recommend against "one-wire" alternators. They are cleaner, but they tend to not charge at idle. This is especially important if you run electric fans and you're sitting in traffic and they're on 100% for an extended period.

I've been down this road a half dozen times and the order proposed above is correct: first, bypass your ammeter and run directly to the battery (with a fuse or fusible link!). Then deal with getting yourself a higher output alternator. After that, you can work on fans, headlights, etc. Electrically, you're looking at the weakest part of these cars... so fix it right.

If you're having cooling problems, maybe post about your setup- unless you're doing something really unusual, if it's overheating then you likely some other problem that electric fans might not solve. On the other hand, if you're doing something custom, maybe you can't even fit a good mechanical fan... and you have no choice.