Alternator might be on the way out...

[aaronrules]

Okay, did a search before I am asking these questions. And I even looked on the OS. I ask you guys here because I value your knowledge and opinions. And really do lean on this site for a lot of GOOD info and advice...I am both thinking out loud and asking a the time right now...plus my boy is right next to me being a little distracting, and I am going on little sleep since being in Afganistan YESTERDAY!!! But I feel the need to bring this up...

So for the past half a year or so every once in a while, my lights inside and out will dim a little bit for a second or two. I am on my third battery since buying the truck in 2004. I have an aftermarket Alpine CDA-7893 head unit installed, which actually draws a decent little bit of power. But the lights dimming has been happening well after the radio was installed. The dimming happens both at idle and when i come off the gas and step on the brakes. They don't go completly out, but you can notice a significant dimming. It happens with the heater/AC both on and off...and with either the daytimes running and at night. I used to have an amp with a couple subs installed, but all that is out, and it was installed, and uninstalled correctly.

I found out that the stock alternator is 145 amps? If I need to get another/new one, how many more amps can i get without having upgrade wires and stuff? I just want to have some piece of mind if and when i add lights and maybe reinstall the subs (the boy likes to jam out with me when are driving around town), and whatever else I want to add that will draw power.

Anybody have any ideas? I don't even really know how to check to see if my alternator is going out or not.

[bartonmd]

Yeah, we all do that... It's pretty normal...

Mike

[djthumper]

If you have a volt meter you can check the voltage coming out of the alternator. It should put out about 14 volts under a load. If it drops below 13.8 volts or wavers you have alternator problems. I would check your belt for unusual wear or problems because that could cause problems also.

I don't see anything except maybe a 150 Amp alternator out there, but others may know more than I do on that since I have only had my TB a couple of months.

My wife had a car that was under warranty that we replaced 5 alternators and 2 batteries in 5 months, I tried to get them to replace the computer but they said they couldn't under warranty. Now days that computer controls so much I told them to take the car back if they weren't going to try the computer.

[irishboy02]

Powerbastards offers a 240a alternator. Was considering it when i used to have my system

[Trail X]

It's pretty normal for a TB (but probably shouldn't be). I notice it much more in my headlights than in my interior lights.

I installed a second battery and I don't notice the dimming once it kicks in.

[aaronrules]

It's pretty normal for a TB (but probably shouldn't be). I notice it much more in my headlights than in my interior lights.

I installed a second battery and I don't notice the dimming once it kicks in.

Well...it's almost like if it's just sitting there running in park, it almost like it's on it way to dieing...but then it kicks back in. I will look at with my father-in-law/guy who knows more than me!

[The Roadie]

If the most noticeable dimming comes in short bursts of 2-3 second pulses, 2-3 seconds apart, starting 5-15 minutes after you start driving, that's a solved problem. It's a diagnostic of the Secondary Air Injection System - the 30 A turbine pump under the driver's seat mounted to the frame rail. To test the theory, let the engine warm up for 60 seconds before driving off. That allows the initial run of the SAIS to complete, and the later diagnostic that pulses the pump then won't be scheduled by the PCM. You can listen with the door open for the first 30 seconds and hear the pump - sounds like an industrial vacuum cleaner. But only if you have a 2003+ vehicle.