Need more amps
 

1967 K10 402 bbc

I know this has been discussed but if possible please refer me to the correct existing thread. I am currently running a 55 amp alternator with stock external regulator. It has stock connectors on the alternator.

I added 2 audio amplifiers that can consume 50-60 amps. If amps are on and I turn on the a/c blower to half my volt meter drops below 12v charge even off idle. This does not include headlights, brake lights, horn, and running lights. If one or the other is off it shows 13v or so on the voltmeter.

I think I need more amps ------ what alternator should I go to that will least effect my oem wiring/external voltage regulator lugs and clocking issues. I run dual batteries.

Have a nice Memoral Day weekend.

thanks

Re: Need more amps
 

Not sure if your serpentine or not, but Summit seems to have a whole section, including minimum amp rating. Maybe you can narrow something from here?

https://www.summitracing.com/search/...8%2B4294951399

Re: Need more amps
 

My 67 is a custom with gauge option. So I will look again but I do not have a dummy light. I removed the amp meter and replaced the slot with a voltmeter. I did see a 1 or 3 wire 10si 100 amp internal regulated for about $95. I would need the correct 2 wire plug and figure out the connection diffs to the external regulator. I am vbelt. Also change the 12 gauge Bat wire and maybe other.

Re: Need more amps
 

Hmm, even if the alt can't provide the current@voltage needed, the battery can. That means your wiring is weak--probably w/ the additional load, or what/where you're measuring is not indicative of what's happening.
I'd be looking for hot spots, making more measurements, etc. before starting to swap parts.

Re: Need more amps
 

I think the oldest of my dual batteries is going bad. I have noticed that if a trickle charger starts to do strange things like the yellow and green light is on at the same time or a very fast charge--- probably a battery problem. I will charge, check voltage, and then put a load tester on it. When ignition is on, both batteries are tied together, when off, a solenoid disconnects them.

Re: Need more amps
 

IMO, if your steady draw is more then the alt can provide, you need a bigger alt. Possible worst case scenario, you are running the stereo, lights because it is night, AC, blower on defrost to clear humidity fog, and wipers to clear the rain. Could well have a draw from the batts of 30+ amps even with max alt output. Not something you want for more then a few minutes.

For ease of installation, an about 94 amp 12SI should be a physical drop in installation. Search some of the external reg to internal reg threads on electrical connection changes needed. For most uses, get the 3 wire version with the remote voltage sense wire. That way, any voltage drops in the primary charge wire from the alt to junction block are compensated for.

Might want to get one of the junction blocks from a 90's era truck to give multiple connection points.

Re: Need more amps
 

One wire alts are for tractors.

Re: Need more amps
 

I was in your shoes a few weeks ago, but with help here, I just did an upgrade to the SI alternator (94 amp). Check out my thread in electrical.

It works much better than the 55 amp setup, solved the problem for me.

Re: Need more amps
 

thanks guys, I will be pursuing this week

Re: Need more amps
 

ok, the battery in question, charged measures 12.92 volts and easily passes the load tester. I will have the existing alternator tested and refer to dave12's thread info and Dead Parrot for a further plan. I will not go to a 1 wire.

Re: Need more amps
 

Was a loose alternator belt. duh... I still may put a higher output alt on it later.

Re: Need more amps
 

I would do that sooner than later, I run my stock rig with fan, lights and wipers I am at a full 54 amps on my system, I had it tested. Currently running a stock 63 amp 10 DN alternator and that thing is maxed out at more than 75 % of working amps.

You will find you need additional amps as most alternators at rated at maximum output. Everything I have read informs me to add an additional 25 percent to keep from burning up alternators from overuse.

Re: Need more amps
 

Toolboxchev, BR3,deadparrot, phat69, franken, Dave12, Davepl, vetvette all --- I did upgrade to a new acdelco 12si 3 wire --78 amps, seems to work well and does not go below 12 volts with everything on at idle. I used the external regulator wiring mod that davepl posted in another thread.

Red to white and brown to blue -- on ext reg pigtail - then white to alt 2 and blue to alt 1.

I do not have a alt dummy light but vehicle turns off ok, seems to charge good.

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Does a stock 67 with gauge options have a built in resistor for the exciter wire on a 10 dn alt and ext reg.?
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Prior I changed the amp gauge to a voltmeter.