I got a OEM set of fog lights a few years back and noticed that when I have headlights on with them and the truck drops to the 500rpm idle they show some signs of dimming. Especially if I hit the windows at the same time.
When I first noticed this I purchased an alternator that pushes 173 amp max and is rated at 160 amps.
My truck came with a 136 amp alternator and also states 136 is max on build sheet.
Is this the largest the trucks' wiring will accept or am I ok in replacing the less amperage unit out for the higher one?
Unfortunately my year truck does not allow changing of idle with my tuner.
The last thing I want to do is cause some problems in my electrical/ecm due to using a device not rated for the circuit.

Thanks for any info,



OEM off-road 17's, BFG LT's, Airraid CAI, Cortex 3950, Magnaflow y-pipe, Detroit TT, Mag Hytec trans and rear, SRT A-pillar w/autometer trans temp, 190 t-stat, pwr stop drilled/slotted all 4, pwr wire, grnd TB

 

You will be good. The truck will only draw what it needs. Lights dimming is a common issue. Make sure you have a good battery as well.

 

Thank you,
Have been chicken to change them out not knowing if it would be OK.
COOL

 

Yep. Mine came with a 136a and when the bearing went I upgraded it to the factory 160a. Voltage regulation is controlled by the PCM, like jfotsch said, it will only draw what it needs. If you have a battery issue, that can cause all kinds of problems that a higher amp alternator will not solve.

 

Thanks,
I really do appreciate all of the help.
I do keep a good battery in at all times. I use a battery reconditioner/desulfator (smart charger)on all of my lead/acid cells. In fact the factory Mopar battery that came with the truck is sitting on my shelf with a glowing green indicator in it but the truck's computer does not like it so I put in a new one every 3-4 years. The desert is really bad on them.
I wish I could find an Optima that would fit and look right in my battery tray. I keep a red-top in the back cargo at all times just for when people ask for a jump because I do not feel safe doing that these days when cars are full of electronics?
thanks,
jfotsch

 

That is normal at 500rpm, with the lights, blower and other stuff running. Not too many alternators can charge that much at 500rpm. I wouldn't worry about it. My 08 has done this since day 1.