Dual alternator setup for 6.5TD?

[Shaun091382]

Is there a dual alternator setup for the 6.5TD for dual 105amp alts? i cant find a setup anywhere I was told that emerg vehicles such as ambulances were equipped with a dual setup but i couldnt find any brackets as such on the net. thanks for any information.

[dieseldummy]

I beleive that in '96 or '97 there was a factory option for dual alternators, so your local dealer should be able to look up part numbers for ya.

Justin

[AndyL]

I think I have seen 200 amp high output alts. Replacing your stock with it would simplify the setup.

[rjschoolcraft]

The 95's had this as a factory option. Everytime I buy a belt, I get asked if I have dual alternators.

[GMCfourX4]

I almost pulled over next to a Boston EMS ambulance yesterday to ask if I could look under the hood :) I was thinking about the same thing. I am going to see what I can find out about it, b/c I figure 2 alternators is better than one, right? :D Does anyone else knows anything about it?

-Chris

[Beedee]

My alt in my 98 just packed it in the other day, when I called the localChev dealer that was one of the first questions he asked me was if it was a dual alt. I have a get on pretty good with the guy, would you like me to ask him about it???
might be a canadian thing for those long cold canadian nights ;) ;) ;)

[Peter J. Bierman]

All CUCV trucks run two, If you have belts you can try that.

Peter

[DAYSU]

I have a 6.5 TD in my 95 Trek motor home and I replaced the stock alternator, 105 amps, with a 135 amp from NAPA. you need to upgrade the wiring to.
Worth a thought.

DAYSU

[pannhead]

i have a 200 amp alt....if you go this route its very important you upgrade your cable...since the alt itself is bigger it required a special bracket.....i have a real old pic if you want..my e-mail is pannhead51@aol.com....by the way,what do you need all the amps for ?

[DAYSU]

Just a quick question on the alternator upgrade. Just to ensure mine was done correctly, what wire, or wires, to and from, need to be upgraded?

95 6.5 TD
DAYSU

[pannhead]

sorry about ignoring your question...the cable from the alternator going to the black box that has all the relays in it..this must be thicker...its also a good time to do all the battery cables too

[DAYSU]

Thanks for the info! Will have it checked

DAYSU

[EscaladeDiesel]

Is the upgraded cable from the alt. to the relay box a factory item or must it be handmade?

[pannhead]

the place i got my alt also had the cable,most places that sell high amp alt will have the upgraded cable also

[Dan Nicholas]

Originally posted by Shaun091382:
Is there a dual alternator setup for the 6.5TD for dual 105amp alts? i cant find a setup anywhere I was told that emerg vehicles such as ambulances were equipped with a dual setup but i couldnt find any brackets as such on the net. thanks for any information. Hi Shaun,

I have a 96 2500 6.5 TD. I haven't completed my dual alt setup, but I can tell you it's definitely an option for my year of truck. I believe the parts are listed under the 3500. The require parts (excluding electrical) are 2 brackets, 1 pulley and a longer belt (from GM). If you have AC you'll need to buy 1 less bracket. Bracket #1 supports the AC compressor and the 2nd alternator (approx $140 from GM). The lower bracket (or bracket #2) is approx. $90 from GM. On my truck, both these brackets are on the driver's side. The required driver's side lower pulley (driver's side) you can get at NAPA. However, I suggest GM (approx. $25) because you get the special bolt used with the pulley. NAPA only gives you the pulley and you'll to visit the junk yard or fabricate something. GM will list 2 pulleys and the listing is confusing because it lacks detail...just remember it's the wider pulley of the 2 they list. I'm sorry I don't have part numbers for you, but if you run into problems I can get them for you with some digging. If this is the case contact me direct at nicholas_danielj@yahoo.com

Good luck.

[Dan Nicholas]

Shaun,

btw, regarding the longer belts for the dual alt setup...I made a mistake, you can actually get those (I buy 2 to keep a spare in the truck) from NAPA for about $20+ cheaper than GM.

[Shaun091382]

Thanks everybody for your replies it is looking more and more like the dual setup was available to those with 95+ or possibly 96+ rigs and probably not and option in '93 i'll have to look into the 3500 series options in that year...worse comes to worse i would just have to go to a larger single but thanks all just the same for the comments

[britannic]

Here's a bracket kit on eBay: Dual Alternators (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2465740278), the seller's got the HD alternators that go with it too.

[GMC Hauler]

Ok. I have been interested in performing this mod for a while. So i researched it and have some info to share.

You do need 2 brackets, an upper and a lower. If you have air conditioning, you already have the upper. Coincidentally, it is GM part number 23556554, named "Bracket, eng lift frt". I do not have a price for that, because i already had one.

You will need the lower bracket, GM part number 10244209, price $78.54.

You will need to provide your own charge wire.

You will need 4 bolts (assuming you already have air conditioning).

You will need 2 of GM part number 11515767, named "Bolt, HFN, M10x1.5x35, 32 THD, 22.3 O.D., MACH, 10.9, 7114M".

You will need 2 of GM part number 11516360, named "Bolt/Screw, HFN, M10x1.2x90, 9.8, 7114M, 22.3 OD HDR PT."

I bought the 4 bolts from a bolt supply store that the dealer said they got their bolts from.

The alternator is the same part number as the passenger side, and is interchangeable, according to the dealer parts guy. The dealer wants $255.42 with a $20 core charge.

Shucks auto parts store wants $153.99 with a $30 core charge. It is an autolote, and comes with a lifetime warranty.

You will need an idler pulley, GM part number 12556504, GM price $16.39.

GM wants $62.36 for their dual alternator belt, part number 12555010.

I have a few questions before i complete my installation:

1. Is there a belt available for dual alternators without the vacuum pump? I am planning to get rid of the vacuum pump as i have the heath boost controller. If so, where did you get it from, what is the part number and what did it run you?

2. The alternator has a 4 pin connector. I tested the need, believing this was only for a tach signal. I disconnected the connector on my current alternator, lost tach signal, but operating voltage stayed the same. So am i to assume thses are 1 wire alternators? (a am pretty sure of it, but would like some backup). Can this plug be left alone and the alternator still operate?

Thanks

I do have the printout from the dealer of what this thing is supposed to look like part by part. I couldnt fugure out how to include it in this post, so if you would like a copy, email me and i will get back with you.

[charliepeterson]

The shop I work at has almost every conceivable vehicle you can think of and some vehicles I still don't know what they do after two years. We have a number of specialized 6.5's and a company named "Power Line" makes HO alternators which will bolt right up. You can use the same belt also. I just put one of these on a truck last week and it was a 160 Amps.

The only issue I can see with an upgrade would be a good clean cable between the alternator and the battery.

I would think a well stocked auto store or auto electric store should be able to locate one of these alternators.

By the way this Alt. was $240.00.

[GMC Hauler]

I know several of you out there have gone with the higher output alternators. Let me explain why i like the dual setup.

It's made with factory parts that are readily available.

2 alternators gives you a built in reliability in the field. If one goes out, the second one is there, automatically taking up the slack within its limits. You would take it easy on the one unit until you get back to civilization.

If you are out on the road traveling, ect.. and a high performance unit burns up, you will have to find a place that sells a hi-po unit, or that can repair yours. If you dont have an address, that can be difficult if it was mail ordered. A factory unit is available at any parts store across the country.

Shucks warrantees it for life. The way i keep vehicles, Shucks will owe me alot of alternators.

JMHO

[DA BIG ONE]

Any of you finish a dual alternator conversion yet?

[JohnC]

OK, I have a question. In the aircraft world, dual alternators are pretty common, on multi-engine planes as well as on singles. There is always a unit that syncronises them and keeps them at the same voltage. Do these trucks with dual alternators have such a unit? If not, how do you avoid different output voltages and the resultant current flow between the two?