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thinking about trying to do a dual alternator set up on on truck. anyone ever do it? also do a second battery.

Why? A 100A+ for a 76 C10 is an easy bolt in, deletes the on firewall voltage regulator, and costs about $65 at NAPA ($10 for a boneyard core). The truck won't know (or care) that you used a Delco-Remy part instead of a Chrysler one. For that matter, if you have a good round case Chrysler core (61-69), you can buy an easily installed overhaul kit that will boost the output to 80 or better amps.

Dual battery is easy, hit the junkyard, pull a set up out of pretty much anything from the mid-80s back, RVs are a pretty good bet. Heck, grab the 120A alternator and brackets while you are at it...

the only reason im looking to do a dual alternator would be to eliminate the draw on my battery. its a brand new alternator and battery and every time i turn on my lights i get a significant drain on my battery. also im looking to install aftermarket goodies that will require some power.

Jake66 wrote:the only reason im looking to do a dual alternator would be to eliminate the draw on my battery. its a brand new alternator and battery and every time i turn on my lights i get a significant drain on my battery. also im looking to install aftermarket goodies that will require some power.

My suggestion is to check/replace the wiring that is causing the high draw. Adding more power is a recipe for a fire.

thats the kicker though, i went through systematically and replaced the wiring one by one. its not like i have a bunch of lights hooked up to it. i turn my headlights on with the truck running and it draws maybe one 1/4 on the draw side. its not causing an issue just want more power so once i put my aftermarket running lights on and tie them in to the electrical, so i dont draw more power than what i want to.

The stock base model alternator is rated at 37 amps. There are bigger ones up to 60 amps as optional equip. If you have the 37 amp base model just running the truck and lights is about all it can do. Just all the lights are probably 20amps.

If you upgrade to one of the ALTs that WD suggested I would recommend you rewire the charging system so the output goes straight to the batt and convert the ALT gauge to a volt meter. The stock wiring runs the full output of the alt through the bulkhead and amp meter then out to the Batt. The wiring will catch on fire. There is a thread on here someplace that explains what to do.

Excellent cautionary post!
John

Jake66 wrote:thinking about trying to do a dual alternator set up on on truck. anyone ever do it? also do a second battery.

Just out of curiosity, is there any particular reason you're doing this?....
John

im looking at putting on some cab lights and the last thing i want to do is blow through an alternator or kill a battery because i pulling more than what my alternator will put out.

Put the lights on a relay.

soopernaut wrote:Put the lights on a relay.

http://madelectrical.com/electricaltech ... ghts.shtml

Does anyone have a recommendation for a good battery isolator?

Junkyard. ANY factory dual battery equipped truck, from 3/4 ton through Peterbilt. Cheap, works, get the entire system of trays, harnesses and isolator. You're overthinking it, flash back to the early days of hotrodding, where pulling what you need off a scrapped vehicle was how you got things done.

If you "need" era correct, that's the only way you'll find it, unless one of our two west coast members with private Swept only junkyards have the parts.

WD wrote:Junkyard. ANY factory dual battery equipped truck, from 3/4 ton through Peterbilt. Cheap, works, get the entire system of trays, harnesses and isolator. You're overthinking it, flash back to the early days of hotrodding, where pulling what you need off a scrapped vehicle was how you got things done.

If you "need" era correct, that's the only way you'll find it, unless one of our two west coast members with private Swept only junkyards have the parts.

ive got a yard here that has a bunch of swepty's. its just a matter of getting in there and seeing what there is.

well, i fixed the issue. i had a wire on my pig tail connector for the ECU that had a break in it that was not allowing my battery to charge, hence the draw on the gauge.now that i have the wire replaced i dont have any issue with the draw on my battery. so im gonna wire up my lights and wire in a relay to help protect the electrical system.

and still do a dual battery setup. it will come in handy when i go camping to be able to have an auxiliary battery.

WD wrote:if you have a good round case Chrysler core (61-69), you can buy an easily installed overhaul kit that will boost the output to 80 or better amps.

any more info about where to find this kit or installing it ??
sounds like a good option for my '69 D100

coelcanth wrote:

WD wrote:if you have a good round case Chrysler core (61-69), you can buy an easily installed overhaul kit that will boost the output to 80 or better amps.

any more info about where to find this kit or installing it ??
sounds like a good option for my '69 D100

Looks like this site has the upgrade kit with instructions.

http://store.alternatorparts.com/partnoho-7004.aspx

thanks !!