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Username Post: anyone done high amp alternators?        (Topic#361545)
Posts: 157

Reg: 03-20-18
06-27-20 07:08 PM - Post#2797341    

Covid -19 paranoia has seriously and devastatingly harmed those of us in the disability community.

If I do not solve my van power and heating problems. It is very likely I will not survive winter. Due to the exclusion of people with disabilities out of irrational fears over covid-19.

I have lost so much access to services and am starting to lose access to food with plenty of money to buy it. Due to discrimination related to irrational fears over covid-19. Like not being able to wear masks due to health complications. Along with other issues that keeps me from getting food in other ways. So physical access is the only means for me.

Also public places are not being opened and I fear that these places will not be open over the winter, Meaning Living in the van 24/7 in minnisota cold winters which been getting colder due to all the volcanic activities over last couple of years.

So I need power for when my van is NOT running and I need it to be able to charge solely off the alternator quickly. Do to exclusion and inability to get landline power.

I think I can up my idle a bit via drilling out the plug in the Throttle body and adjusting it up because at its lowest it runs at only 485 rpm at idle.

Its almost entirely stop and go driving I am doing so the alternator needs to have high output at idle. but my issue I am seeing is the base idle vs the voltage. How high can I increase the voltage on the system alternator output?

THe factory only does 13.5 volts at idle. THe X2 power battery when first installed was 14.3 volts.

The factory alternator is seriously struggling to charge the battery. THe battery has now dropped in voltage too low twice in single year. because the alternator is unable to fully charge the capacity of the battery.

The factory alt is working flawlessly. So what ever I do I need to upgrade the alt. but problem having is finding the right one for stop and go that won't fry the van but also charge a solid core high capacity battery or battery with house batteries quickly. SOlid core agm top battery post goes straight through the core no wires between post and core. This allows dumping high amps possible with minimal harm to battery. Unlike other AGM's.

Right now am considering going two batteries get a starter battery and use the current dual purpose battery as house battery. so need to isolate the two off the same alternator as well.

I get generally what I need to do but my head starts swimming with too many details when trying to visualize how the system will work, especially when I don't have the system right in front of me to look at.

What ever I do is going to be custom, I get that unless someone know actual working kits that can be thrown in.

I am trying to avoid adding a second alternator on the basis that you can't charge one battery with two alts.

I am trying to keep costs down because I could suddenly lose this van which almost happened last fall, when rear ended by distracted overly aggressive driver.

but was prepared to pay up to $800 or slightly more if second battery is involved.

Would like to stick to factory mounts since do not have a shop to custom build brackets etc.

Van spec 1987 GMC g2500 vandura 4.3l v6. The alt is a single wire off back I believe its a 4pin connector. to the internal regulator. the belt is a 4ribed serpentine. (NOT 6)

I was looking at either a propane based heater that exhausts through the floor or a diesel heater. with a tank in cab. thinking modifying a fire safety fuel can . I am already carrying propane in van using the kwik trip 20lb tanks?

but need power to run the fans etc, when van is off.
problem I am having with that besides the power is getting it shipped to me being I have only a P.O. box. and these businesses refusing to return my emails to resolve shipping issues etc because the local assesory truck modifying shops refuse to special order things from their catalogs and or can't because the manufacture is anal about who they distribute to.

in terms of the heater REFUSE to buy the Chinese knockoffs Their circuit board is exposed to condensation etc. and they claimed it was gas powered when it was in fact a knockoff of the diesel version. based on youtube review comparing the two.

the heater system about 600-800 thus why I put limit at about 800 for power system upgrade.

I am relying on the stimulus to pay for the bulk or all of what ever I do. NO I have not spent that yet.

Any help that you could provide would be greatly appreciated and could possibly save my life.


PS I wrote this while sitting outside on the ground of the CLOSED library.

when asking Questions its related to van I own: 1987 GMC 3/4 ton G2500 vandura, V6, No AC, standard length. 3speed trans(no overdrive).

Edited by VanLife on 06-27-20 07:43 PM. Reason for edit: No reason given.

Member #271 Senior Chevytalk Moderator
Posts: 25179
Loc: Austin, TX 78748
Reg: 05-09-00
06-28-20 09:34 AM - Post#2797369    
    In response to VanLife

Increasing voltage above 13.5 is not a good charging gauge. Increasing amps does help. I'm running a 165 Denali amp alternator in my truck. It's amp hungry due to dual cooling fans, A/C demand, power options, and stereo equipment. When the battery goes low for alarm use or non driving time, a quick boost starts it up. After a short drive, the 165 amp alternator charges the battery enough to keep starting it over and over. A stock alternator should be able to go 110 amps. Camaro and Corvettes used 110 amp or higher models. Can you identify the alternator model? Or send me a pic and I'll post it.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE

Senior Chevytalk Moderator -- Performance Subject Matter Expert --
Posts: 17510
Age: 72
Reg: 03-16-01
06-28-20 10:45 AM - Post#2797374    
    In response to gchemist

heres a 200 amp alt for the 88-91 corvettes
I installed on in my 1985 corvette and it made a significant improvement,
in the cooling fan speed and ignition spark strength, smoothing the idle.

Call (800)753-2242
they are knowledgeable and if you ask questions before buying youll have zero problems ... 0-amp.aspx

related links and threads


Edited by grumpyvette on 06-28-20 10:47 AM. Reason for edit: No reason given.

Super Senior Member
Posts: 5635

Loc: paradise
Reg: 09-05-03
06-28-20 12:13 PM - Post#2797380    
    In response to VanLife

you may need to add on deep cycle batteries. a regular battery does not like to be deep cycled. i would try to get your vehicle as insulated as possible.

70 L camino, grampa engine, g-force 5 spd, road rage suspension. Pray first before all else fails.

"2nd Year" Gold Supporting Member
Posts: 14
Loc: Riverside county ,CA
Reg: 04-05-19
06-29-20 08:16 PM - Post#2797495    
    In response to VanLife

check out high output alternators 865-522-6166

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