dimming lights while driving

[Chillin014]

I dont remember having this problem until after my transmission swap. but to keep this short here is what happens :

When driving the dash lights and headlights are fairly dim, when I rev the motor or accelerate quickly the lights brighten SIGNIFICANTLY. The battery is not old. Would this be an alternator about ready to go?

like I said they brighten with acceleration/higher revs NOT the other way around.

recommendations for alternators? i see prices from like 50 bucks to 200+ bucks on rockauto.com

 

[STLRegal]

My car does this too. In my case I think its the belt because it is starting to squeal alot when I hit the gas when it isnt warmed up.

 

[Derision]

When driving the dash lights and headlights are fairly dim, when I rev the motor or accelerate quickly the lights brighten SIGNIFICANTLY. The battery is not old. Would this be an alternator about ready to go?

like I said they brighten with acceleration/higher revs NOT the other way around.

Yeah, sounds like a crappy and/or underpowered alternator. I've had that happen to quite a number of cars. Usually just get the OEM replacement; they're usually about $100, with a $30 core rebate.

 

[SBCregal]

grounds grounds grounds grounds



did i mention checking the grounds?

 

[megaladon6]

check the condition and tightness of the belt first. 99% of the time that i see this on old cars it's a slipping belt. if tightening/replacing the belt doesn't help, check your major grounds esp. the battery and engine. most parts places have a decent battery/alternator tester and will do it for free.

 

[Chillin014]

i was thinking grounds too because nothing seemed wrong necessarily before the transmission swap. I dont know what grounds I could have disrupted though. an exposed wire was causing sparks under there when i was messing around with the dipstick tube but i found it and wrapped some electrical tape around it.

anyway...I should have the alternator tested, yeah. I dont think the belt is loose my dad and I tightened it pretty good a couple days ago. He was saying alternator, but i thought it was grounds too. The alternator is old as hell though and when the lights brightened they were brighter than I had ever seen before...like I could ACTUALLY see my freakin' dash lights at night for once in my whole life.

 

[pontiacgp]

there is a grounding strap from the firewall to the engine that's in the back of the engine just above the transmission....that might have been broken especially if the engine was allowed to drop when the transmission was removed

 

[megaladon6]

since you said it got better with RPM's i would doubt a gnd other that at the batt or main engine to body being a problem.
that wire that was sparking, it is connected to something now right?

 

[pontiacgp]

The alternator is old as hell though and when the lights brightened they were brighter than I had ever seen before...

I missed this before....that's caused by the voltage regulator in the alternator..

 

[Chillin014]

i removed the engine/chassis ground because it was connected to like...frickin goop thats all over the firewall...some kind of black sealant or something, looks like crap. i'll have to put it back.

i'll have my alternator tested regardless though. thanks yall.