340 Alternator Question?

[cudacarl]

I've got a '73 'cuda w/340 wo/a/c 4 speed. It originally had a 30 amp alt but i recently bought a 75 amp chrome alt from summitt made by Powermaster. Am i going to burn stuff up or is it just bolt it in. Its the double field one, not the single wire.

[ehostler]

Is it a GM unit or is it a true MOPAR dual field?

If it's a GM unit, I'm not sure how you would wire it up. I think that they used one wire for batt, one for the alt light, and one for the regulator.

If it is a MOPAR unit, just add a second battery lead. It should be a minimum of 10g (an 8g or 6g wire would be a better choice). It will run from the alt to the battery pole on the starter relay. That 10g wire is good for 30A and the existing wiring is good for about 50A.

[bbeckwith]

Glad I saw this thread, I have the same alternator, been running it for around 9 months now with no problems but think I will run the additional 8g wire too! Better safe than sorry.

[riverside]

ehostler; Thankyou that was my next project.

[ehostler]

As far as an alt upgrade goes, there is a good thread, in the archives. It is for upgrading to a 130A alt. Search ebaymotors for 130 amp. This alt should come up. if it doesn't, I have the email address of the place that is selling these near new alts for $74 + $15 S&H.

[riverside]

Do you know about the quality of these units?

[ehostler]

The shop that is selling them is doing Ambulance conversions. The 130A alts are being pulled off of brand new Dodge vans. They have very limited run time (probably less than 1 hour).

[George G. Leverette]

If these are Mopar units what are the casting or part numbers? Would like to compare the new Vs used cost.

[ehostler]

I don't know the casting numbers off hand. Take a look in the archives and get with the guy that has actually converted to this Alt.

I do know that as it is an '02 alt pushing 130A that the new price is a minimum of $240 (that's about the new price of the 120A unit that's in my '96 Ram).

[ehostler]

Here's the information that you asked for. I got the information from the sale that they just put up on ebay.

THIS 130 AMP DODGE / DENSO ALTERNATOR COULD COST YOU WELL OVER $230.00 AT YOUR LOCAL MOPAR DEALER * YOU WILL OWN IT HERE FOR ONLY A FRACTION OF THAT!
COMES COMPLETE WITH Serpentine Belt & Idler Gear!
PART # 914AB * MADE by DENSO MANUFACTURING TENNESSEE, INC. * DENSO PART # TN121000-4451 12V
THESE ALTERNATORS ARE TAKEN OFF NEW DODGE 1-TON VAN AT AMBULANCE CONVERSION SHOP & HAVE VIRTUALLY NO USEAGE ON THEM!

[cudacarl]

According to Summitt and Power Master it is a true dual field mopar setup direct replacement. The only difference from stock is it's chrome and 75 amps instead of my 30 amp. Knowing this can i just bolt it in and wire it using the stock wires or do i have to run new thicker guage wires?

[ehostler]

If it is a MOPAR unit, just add a second battery lead. It should be a minimum of 10g (an 8g or 6g wire would be a better choice). It will run from the alt to the battery pole on the starter relay. That 10g wire is good for 30A and the existing wiring is good for about 50A.

[George G. Leverette]

Thanks for the info on the price of the Denso Alternator. I am one of those people that always get three prices from different sources before I make a purchase. $240.00 list price translate to a real world cost of approximately $165.00 with a new part warranty. These forums are excellent exchanges for information and I appreciate all comments and input.

[Tarrbabe]

While everyone is on the subject, anyone know what the 87 Cop Car came with. I know where to get one real cheap.
It sure is a big sucker.

[George G. Leverette]

I have one of those on the garage floor, it is a 100amp alternator it also came on other heavily optioned cars. That cooling fan is as big as the alternator. The bracket to mount the alternator could cause hood interference depending on the make of car.

[Tarrbabe]

Thanks George. That helps me out
They do hook up the same dont they?

[George G. Leverette]

Yes, hook ips are the same.

[cudacarl]

I installed the 75 amps alt and ran a 10g wire (i couldn't get 8 or 6g) from the alt to the batt terminal of the starter relay. When i started the car the alt guage started creeping towards discharge. I was affraid i'd burn up something so i shut it off and discannected the extra wire. Then it worked fine. Hooking up the extra wire like i did does it bypass the alt guage or did i do something wrong? I went from the alt to the batt stud on the relay were the fuseable link is connected. - thanks

[cudacarl]

Also is there an order to the wires on the relay as far as who is on top. I think i remember someone telling me that years ago.

[ehostler]

The 10g wire that you connected to the Batt side of the starter relay is brining current around to the other side of the gauge. As it was begining to go into discharge, that tells me that the wiring on the battery side of the gauge has less resistance than the ALT side of the gauge. Current will always flow down the path of lest resistance.

As far as wiring at the voltage regulator goes, you shouldn't have messed with that. Only the field wires on the ALT. As far as the alt goes, the field wires are interchangable and doesn't matter which wire is connected to which field position.

[cudacarl]

I didn't mess with the regulator. What i'm asking is on the batt terminal of the starter relay there are two wires in the stock setup and i think i remember some one saying the one of them should be on the bottom and the other on top.

[ehostler]

On the upper terminal (BATT) (about center on the relay), there is the battery lead and the fusible link lead (doesn't matter which order they are sitting on the terminal) and on the lower terminal is the starter lead.

Is that what you were looking for??