Alternator Question

[tugboatphil]

I've noticed 80 and 90 amp alternators for our trucks. I just saw that 2nd Gens use a 160 amp, I'm guessing because of the second battery. I'm sure I know the answer, but would the more powerful alternator fry our system?



Thanks.

 

[drturf0]

i've got a 120 amp on mine

 

[Paychk]

92 & 93's came with a 120 A. Alternator, not sure of the others.

 

[JLEONARD]

My marine Cummins has a 130 amp as standard (19 SI perhaps?)... . it's an AC Delco internal regulator type. There is also a 160 amp available.

I think you can put any size alternator you want to as long as the "charging wire" (don't know the proper term) is large enough to handle the current. I know I had to upgrade that on my boat.

The alternator only puts out what the system needs... . the internal regulator on the modern alternators determines that.

I am thinking about putting one of those more modern larger alternators on my rig when that time comes... I know I'll have to do some re-wiring to lose the external regulator, but it can't be that difficult to do.

Jay

 

[dpuckett]

My "91" (11/90) has a 120 amp on it. JLEONARD- good luck losing the external regulator. I'd rather have it than one in the PCM or in the alternator. WHat is the real advantage of internal vs external regulators? JUst curious. Seems to me an external would be easier to replace, but the internals may last longer. THe true 91s and up have the regulator in the PCM

IT is amazing the inconsistencies among the earlier first gen trucks. I talked to a guy with a W250 that had the light futy 5" frame rails; some have a 120 or 90 amp alternator. 2. 5" vs 3" brakes, tire differences, tha list goes on and on.



Daniel

 

[BushWakr - RIP]

Keep in mind that (as I understand it) those amperage ratings are not continuous duty ratings, but rather Peak rating...



Bob.

 

[JLEONARD]

Keep in mind that (as I understand it) those amperage ratings are not continuous duty ratings, but rather Peak rating...

Bob, true, but at normal driving rpm, a higher rated unit will put out more than a lower rated one.

Based on my experiences in boating, that could be pretty significant, especially if you are doing mostly short runs and are having trouble getting the batteries fully recharged... . especially in winter with the cycling of the grid heater.



Daniel... . I just have never had any trouble with internally regulated alternators... . but I've had a few Chrysler products in the past with the external kind and have had my share of troubles... . enough that I don't trust them as much... to each his own I guess.



Jay

 

[CDegner]

Originally posted by dpuckett

THe true 91s and up have the regulator in the PCM

IT is amazing the inconsistencies among the earlier first gen trucks. I talked to a guy with a W250 that had the light futy 5" frame rails; some have a 120 or 90 amp alternator. 2. 5" vs 3" brakes, tire differences, tha list goes on and on.



Daniel

Not quite true about the internal/external regulator. I have a 91. 5 (intercooled, etc. ) and it has the external regulator, 2. 5" brakes, 120A alternator, etc. My truck does not have a PCM. It has an SBEC (Single Board Engine Controller) located behind the battery.



Carl

 

[MrWinkey]

I can offer a little bit of insight here.



The SBEC handels the alternator feild coil output as it's an all in one unit.



From my expirence w/ turbo dodge cars all cars 91 and up have the SBEC. Some late 90's have the SBEC. Everything 90 and under has a SMEC.



For more general information on how these work go to this url.



Understanding The Chryco Engine Controll Unit



This is for Turbo Dodge cars but alot of the program logic should carry over for our trucks. The fault codes may be diffrent for your application as they are in our cars.

 

[Paychk]

On the 92 & 93's that black box behind the battery is label PCM, I know SBEC is the term used on earlier Dodge products, I wonder when the switch was made?

 

[MrWinkey]

I'm sorry I should have been more specific.



91 and up dodge cars have the SBEC.



88-90. 5 have the SMEC (Same as SBEC but diffrent boards and code inside the computer)



87 and lower has the Logic Module (LM) and the Power module (PCM)



On our trucks I dont know if they ever switched. You dont really need the SBEC/SMEC as our timing/igntion events are done w/ the mechanical pump.



Ideas anybody?

 

[dpuckett]

CDenger,



I stand corrected. The 91. 5 I had didnt have an external regulator. Not sure what size brakes- didnt have it long enough to have to replace them.

 

[Wayno]

A friend of mine just sold a 91. 5 - D250 4x4 that was intercool ,automatic that had a external regulator ( that was factory ) on it and black who knows what behind the battery . I know he lost the cruse control and the transmission overdrive shift and was going to have to replace the box behind that battery but he sold it and the next owner changed it . The truck was bought new in California .

 

[Sarge]

I believe the 97 I had was a dual batteryand a 120 amp alternator as well. I have heard the bigger alternator was to power a higher amp block heater... ...