alternator probs part 2

[K_Arts]

Well guys...



Got the truck back and of course my dealer can't see the fluxuation in voltage that my alternator is giving me. Never mind the fact that the voltmeter on the dashboard keeps moving in between 8 and 14 volts. Everything is perfectly normal.



geesh. . I hate dealers.



Now for the question. Does anybody know if I can cause any electrical probs by putting on a bigger aftermarket alternator? I found a stereo shop (Stinger Electronics ) that makes aftermarket alternators but they don't carry a 136 for our trucks like what I have. Instead they have a 150 amp alternator that will fit. What kind of problems can that extra power cause? Is it a bad idea to get a more powerful alternator?



I figure everything electrical is probably fused off and wouldn't cause any problems but thought that I'd ask you guys before with my luck I blew something up. . LMAO



Thanks a million



Kev

 

[SS]

No problem, especially for such a minor change - in fact it's probably better IMHO. I know at least 25 people that have upgraded alternators on 4x4's (mostly Jeeps) and have had no issues. Some have carburetors and some are computer controlled. When you add winch, off-road lights, CB, etc. you're glad you have the added capacity.



Have them check your alternator before you purchase a new one just to make sure it's not a gauge issue. Good luck.

 

[K_Arts]

Originally posted by DodgeTorqueWagon

Have them check your alternator before you purchase a new one just to make sure it's not a gauge issue. Good luck.

Actually I had the dealer check everything. . and they are a bunch of incompetent fools.



My father and I sat at the batteries with a voltmeter..... and about every 15 seconds the voltage would go down to about 8 volts, then trickle it's way up to 14, then settle back down at 12. 93.



We made sure the truck was warm so that we didn't have to deal with the grid heater. So we are positive the alternator is on it's last leg.



Thanks for the info. . I appreciate it



Kev

 

[Fuzz]

Kev,

Over the years when I suspected Alt. trouble I would take the

altn to a Auto supply place and have them check it on their machine.

Haven't needed to do this in sometime but,Big A,used to do it,and

CarQuest and Napa. As I remember some could do it on the car.

Just a thought.



As far as a higher output Alt. The more the "gooder". Here is a caveat... on some of the higher output ones they actually put out less at idle speed than OEM. The higher amps don't start until you reach a higher RPM. Had one like that,didn't like it. Wasn't much good until I reached cruise. Something else to ponder.

 

[Diesel Freak]

8 volts at the terminals on a fully charged battery with the engine running indicates a HUGE current drain..... possibly a short.

 

[WestTN]

alternator problems

If you are getting voltage drops to 8 volts and then drifting back up to 12. 9 , then your heaters ARE cycling! They are a big load. If this is just happening for a few minutes after starting the engine, that is normal activity. If the engine is still cold the heaters can also start a new cycle to raise the intake air temperature.

 

[K_Arts]

Re: alternator problems

Originally posted by WestTN

If you are getting voltage drops to 8 volts and then drifting back up to 12. 9 , then your heaters ARE cycling!

We ran the truck for over 20 minutes to get it warm. . I can guarantee you that the heaters were not cycling!!!!



It is around 50 degrees outside and the truck was at operating temps.



It is possible that there is a short somewhere. . but I have no idea where. These voltage spikes are very weird.



I also noticed that when I turn on any anything, vents, stereo, headlights. . etc. The voltage also dropped down to about 8 and then trickled itself back up to 12. 93 after about 20 seconds.



Kev

 

[LSMITH]

Unless you want to take it in start disconnecting things one at a time to see when it goes away. It is going to be one of the really power hungry circuits or several circuits that are causing the problem for the swings you are seeing. I agree with Diesel Freak, it is a major drain or a direct short. The grid heaters are the number one suspect, they are the only thing I know of that can pull that kind of load without bright lights and smoke. Disconnect them all together and see what happens with the voltage. If you have a clamp on type of amp meter you can do this without taking stuff apart. We all know what happens when you let the bright lights take the smoke out of something electrical

 

[Diesel Freak]

I disconnected my grid heater relay trigger wires and I have not had any more problems smelling anything hot... . except for a couple of rough starts and some blue smoke clowds while things warm up.



I am going to take the computer completely out of the loop and install a momentary switch in the cab to operate the relays on the really cold mornings.

 

[Diesel Freak]

It has been a while since I have played with Ohm’s and Kirchoff’s laws, but if voltage is dropping to 8 volts on both batteries then I think there is about a 400 amp total drain…. Assuming a . 01 ohm internal resistance on the battery…. if I am wrong…would someone please correct me.

 

[SS]

Fuzz makes a good point about ratings. Made me think of something I didn't think to say the first time. All alternator ratings are not equal - can be RPM dependent and can also be hot or cold rated. It sounds like the one you're looking at is about equivalent anyway, but might be something else to ask before you buy. It would still be worth having them check it off the truck because of the load that might be causing the fluctuation - maybe you can even get them to show ratings of both alternators under same conditions. Hope you get it fixed.

 

[craftybigdog]

Check the battery terminals

Hey take each battery cable off and clean it both positive and negative and make sure when you put them back on their tight I had a problem like this and it was a loose negative cable hope this helps

 

[15w40]

Changing from the Dodge alternator to an after-market one will be more complicated than just swapping the alternator. The PCM contains the voltage regulator circuit and is designed to work with the factory alternator. Unless the new replacement is designed to be a drop-in replacement, you will have to add the voltage regulator circuit also. One nice feature of the factory charging circuit is that the charging voltage is adjusted depending on the battery temperature. This allows the alternator to match the charging requirements of the battery for a faster charge and longer battery life.