Voltage problems

[bmk6795 10+ year member]

Ok long story short, when i accelerate the voltage drops to about 12.5 volts. This doesnt happen all the time however it happens often. If im on the interstate and the rpms are 3k+ the voltage stays at 14.4 volts. When im crusing around town and i let my foot off the gas the voltage goes back up, but as soon as i hit the gas again the voltage drops. This is all without any music on. Any ideas what this could be? Ive got the stock battery and alt with the big 3 done. Ive checked every ground for the big 3 and for the amps and they are all good. Ive tried a different battery that i know is good and that didnt work. Tightened up the alt belt because i thought that was it and that didnt fix it. Ive had the batt and alt tested at parts stores and the alt came back ok. I dont think its the pcm just because it doesnt do this every single time i drive. Any ideas as to what could be going on?

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[sexy 10+ year member]

Ok long story short, when i accelerate the voltage drops to about 12.5 volts. This doesnt happen all the time however it happens often. If im on the interstate and the rpms are 3k+ the voltage stays at 14.4 volts. When im crusing around town and i let my foot off the gas the voltage goes back up, but as soon as i hit the gas again the voltage drops. This is all without any music on. Any ideas what this could be? Ive got the stock battery and alt with the big 3 done. Ive checked every ground for the big 3 and for the amps and they are all good. Ive tried a different battery that i know is good and that didnt work. Tightened up the alt belt because i thought that was it and that didnt fix it. Ive had the batt and alt tested at parts stores and the alt came back ok. I dont think its the pcm just because it doesnt do this every single time i drive. Any ideas as to what could be going on?

I work on alternators and I would suggest you get someone else to test the alternator. Auto part stores do a terrible job of testing because their equipment not much more than a fancy test light and their training on said equipment is a joke.

 

[jteske88 10+ year member]

yeah i would say bad alt, loose conection or its has somehting to do in your pcm regulating it.

 

[dbeez 5,000+ posts]

Had this happen many times on my 2002 pontiac bonneville sle every time it was the alt something about the internal regulator. Had a shop guy say it was fine and then tbey would get in the car with a handheld computer and as we went down the road the regulator would shut off frequently while accelerating. Sometimes it wouldnt put new alt in and problem solved their alt guy was horrid they eventually went to another guy locally and never had another problem

 

[bmk6795 10+ year member]

Had this happen many times on my 2002 pontiac bonneville sle every time it was the alt something about the internal regulator. Had a shop guy say it was fine and then tbey would get in the car with a handheld computer and as we went down the road the regulator would shut off frequently while accelerating. Sometimes it wouldnt put new alt in and problem solved their alt guy was horrid they eventually went to another guy locally and never had another problem

So you put in a new alt and problem solved?

 

[bmk6795 10+ year member]

yeah i would say bad alt, loose conection or its has somehting to do in your pcm regulating it.

Well i went to my local honda dealer and when i asked him if the pcm would do that he looked at me like i was ******g stupid. So i went to another one across town and another guy said the same thing so i doubt its the pcm.

 

[dbeez 5,000+ posts]

So you put in a new alt and problem solved?

Yes my alt was internally regulated and supposedly it kept dying shop replaced 3 under warranty from same place finally went to autozone and bought one and never had another issue shop also dropped that guy as they had a ton of alts that kept going bad and was costing them money on labor.

 

[bmk6795 10+ year member]

Yes my alt was internally regulated and supposedly it kept dying shop replaced 3 under warranty from same place finally went to autozone and bought one and never had another issue shop also dropped that guy as they had a ton of alts that kept going bad and was costing them money on labor.

Alright man thanks for the help, guess i gotta find a new alt =/

 

[joselr3668 10+ year member]

might as well upgrade alt

 

[bmk6795 10+ year member]

might as well upgrade alt

Yeah I'm gonna while I'm at it, the alt on this car is a fuc king bitch to get out

 

[mlstrass 5,000+ posts]

Well i went to my local honda dealer and when i asked him if the pcm would do that he looked at me like i was ******g stupid. So i went to another one across town and another guy said the same thing so i doubt its the pcm.

Do a search as a LOT of hondas are PCM regulated to shut the alt off for fuel economy. My son's CRv does the same things yours does, PCM at work...