voltage drop on acceleration

[storlied]

Any suggestions? It was getting as bad as 12.6 to 12.4 sometimes, I changed the alternator and everything was good again. (also, just to throw it out there.. recently, within weeks replaced the battery with a brand new one due to my other one being bad, had it warenteed out) After the battery and alternator change, it's still dipping, but only from 13.2 to 12.8 only on acceleration... while sitting still I'm at a good 14.4 to 14.8. I've already checked the basics, cables.. cleaned up of corrosion.. turned everything off while monitoring the voltage. All of these issues have forced me to finally go out and get relays for my HID's or they wouldn't want to fire up without flickering due to low voltage..

And yes, I've brought it to shops for the battery/charge testing and they report everything is in working order.

 

[BrooklynBay]

Check the condition of the cables, and see if there is corrosion on the area where the ground cable connects to the vehicle.

 

[storlied]

no corrosion on any grounds that I can findm very very little corrosion on positive.. which I've cleaned and even cleaned today (there wasn't much at all) and still the same issue.. this is odd.... good voltage at idle... and then it's like the alternator cuts it's output from 50-90% when the gas is pushed.

 

[2000StreetRod]

Interesting problem! There are not many electrical items that increase power consumption with engine speed to consider. The fuel pump is one since it pumps more fuel the faster the engine runs. However, the pump normally does not require much power.

Does the voltage drop when driving and in neutral?

Does it happen when all of your audio and lighting accessories are off?

Do you have a temperature controlled electric radiator fan?

Could it be a loose connection triggered by movement of the engine when it accelerates?

 

[storlied]

I've checked connections, they're all tight.. I was thinking about that though... I'm using the stock belt driven fan. Happens with everything off, and everything on.. it's just hella worse when everything is on... last night I turned everythinng I possibly could have on..... oh man... 11.9v but no rpm/driveability issues?? The voltage drop will happen wether I'm driving or in park... it's any throttle use... and it's not so much a voltage drop... I mean it is.. but it's more of a charge rate decrease...

Just an example here.. I just went out... started the truck up. (voltage while sitting there turned off is a lil low at 12.4v) It's not staying at a higher voltage since it's not getting a good charge while driving... anyways... sorta slow start due to low voltage... and while sitting there... I'll have a good 13.8 to 14.0.. and Sometimes 14.8v... but this time sitting there it's at around 13.8 so I revved up a little bit and it's just fluctuating around 13.0-13.2.. and god forbid I turn anything on....... now when driving around and on the gas... it'll jump around quite irratically in the 13s (with everything off) and rarely while at a stop it'll go high 13's to low 14's... I just don't get it...

 

[BrooklynBay]

It could have a slipping belt or a bad voltage regulator. By the way, happy birthday!

 

[my98nnj]

I bet the surp belt is slipping. It's also the only item you neglected to replace and one of the cheapest parts too.

 

[storlied]

I'll take care of that today my98nnj, and thank you BrooklynBay.

 

[Joe Dirt]

I was having a similar problem when I first got my Ex, and replacing the serp belt fixed it...

 

[storlied]

What would be other symptoms would a slipping belt have? I mean this can't be the only one?... But I'll replace it either way.. this is getting ridiculous..

 

[Mbrooks420]

Does it ever chirp or squeak when first starting? It might be the only symptom if it only happens under load.

 

[storlied]

It used to a long time ago... hm.. I'll report back after the belt is replaced.

 

[storlied]

Haven't replaced my belt yet (waitin til payday on Thursday), but a new problem has started... was driving pretty hard on the way back from work last night and I start to notice my temp gauge started shooting up... and I pulled over n chilled for a bit by the time it reached the H line... could this be the belt slipping on the water pump or am I looking at more problems?..

 

[my98nnj]

could this be the belt slipping on the water pump or am I looking at more problems?..

Absolutely, and the fan not turning would def. cause that issue.
I think you really need to get that belt replaced.

 

[storlied]

Happened again tonight, belt will be replaced very soon. I'll just take it easy on the truck until then. Who knew a belt could go bad in a way such as this? Usually ud think it just snaps, and that's how they go... but I guess all that heat can have its toll on the surface of the belt over time causing it to slip. Pretty lame considering this belt was replaced just this previous summer... hm.. thanks for the help everyone.

 

[techieman33]

Buy a good belt this time, belts can stretch out over time, they don't just snap when they fail. And if you must continue to drive it be very careful, your motor should not be getting that hot, and it could fail at any time.

 

[storlied]

The belt I put in was one given to me by the previous owner, new in package. Any specific brands that are better or anything?

 

[BrooklynBay]

The Motorcraft is a heavy duty belt, and cost a little more than other belts. I've gone through other brands faster which didn't last as long.

 

[2000StreetRod]

Belt tensioner

. . . Who knew a belt could go bad in a way such as this? Usually ud think it just snaps, and that's how they go... but I guess all that heat can have its toll on the surface of the belt over time causing it to slip. . .

Check the belt tensioner. Even a new belt will slip if the tensioner doesn't properly tighten the belt.

 

[celly]

The belt I put in was one given to me by the previous owner, new in package. Any specific brands that are better or anything?

Goodyear Gatorback came highly recommended to me and hasn't disappointed. Super quiet.