Difference in alternators?

[StealthModifier]

My alternator is about to take a crap. Ive pulled up the alternators for my car an there are 2. One is a 90 amp 5 groove and the other is a 110 6 groove. does it matter which on i get? its only a 5 dollar difference. Im guessing the 110 would be better if there are a bunch of accessories?

also what voltage are u guys running during the day(no lights on) an at night(head an fog lights on)?

[Stealthee]

110 is for a TT but it should work just fine on your car.

[StealthModifier]

alright. i found out the 90 is just for the SOHC. so what is the average voltage with all lights on?? heres where mine is...

[AutostradaVR4]

im running ~14.25 lights off, ~14.15 lights on.

car was cold when i checked this, dont know if it changes when its at normal operating temps.

all this is assuming my turbo timer is accurate (which it should be)

thats definitely seems low though. hope you got jumpers in your car just in case.

[elon3kgtslowner]

haha theres no way ur alternator is putting out any less than 12 volts with ur lights on, its a 12 V system. u'd be running on less than pure battery if that were true. i'd suggest a multimeter from home depot for 30 bucks to see whats really going on. im running low 14s to mid 13s depending on engine temp and loads (electronics, wipers, high beams, and fan all on) but my alternator is brand spankin new since the old one gave out on me. i recently upped the idle on it though so i'll go and re-check tomorrow where i'm at. 14 V is perfectly normal to provide the 12, give or take, for the necessities of the car and an extra bit to charge the battery. test the battery too with the engine off to see how much it's putting out, should be around 12. if its low the alternator should be putting out more trying to charge it. if its low with the car off and normal with the car on, ur alternator is probably not putting out enough. and yeah btw, my in-dash doesn't read near true voltage either, sometimes 17 V, sometimes 12, haha bull. now granted im not an expert, but i've spent the past two months getting my 3rd alternator straitened out so all the above should be right. if its not im sure someone will post otherwise. oh yeah and if u dont want to drop the dough for a multimeter, some shops will use their own for free but don't get suckered like i did a while ago. u'll just about NEVER need both a new battery and new alternator at the same time.

[elon3kgtslowner]

so um, how do u know ur alternator is going? just from the in-dash?

[Linebckr49]

Originally Posted by elon3kgtslowner

haha theres no way ur alternator is putting out any less than 12 volts with ur lights on, its a 12 V system. u'd be running on less than pure battery if that were true.

more evidence that the stock gauges are crap. we've know the stock boost gauge on the TTs are crap for sometime now. and many TT owners have had oil pressure issues (spun bearings, etc) and DO complain a lot about the accuracy of the stock gauge. i think we can add the voltage gauge to that list as well.

[AutostradaVR4]

Originally Posted by elon3kgtslowner

u'll just about NEVER need both a new battery and new alternator at the same time.

exept in my case with my chrysler. the alternator was putting out WAY too much voltage and F'd the battery up...

[elon3kgtslowner]

ah yes, let me rephrase that. if your alternator dies, 99% of the time you don't need a new battery. and if your battery dies, 99% of the time you don't need a new alternator. but yeah overcharging will def fry a battery. when it was overcharging did your lights flicker really bright, both in-dash and the forward pointing ones? cuase i had one replaced and thats what it was doing, but this was when i was 16 and didn't know anything about cars.

[StealthModifier]

well i know the alternator is bad because i had the car running today and disconnected the battery. car shut off. i was told if the alternator was good that the car will keep running even with the battery disconnected. also when i started it up cold today it was at 14 volts. when it warmed up i was at 12.5 with lights and everything off. turn the lights on an it dropped almost a volt. but the longer i drove the car the lower the volts were getting, like the alternator wasnt charging the battery. so i brought it home b4 the battery died. so now i have a battery charger on it an its been charging 3 hours now an the battery still isnt full. im going in the morning for a new alternator from NAPA.

my alernator went bad a few months back. it was just out of nowhere. i got in my car after letting it sit for a few minutes. turn my headlights on an they seemed like i had HID. looked at the voltage an it was around 14 or so. so took off and when i was driving it the volts would skyrocket and it was way past the red bar. then come to a stop an the volts would go to around 10 or 11. so when it was maxed out past 16 i was like lets see what the bright lights can do. so i turned them on an the were flashing out a bright blue so i turned them off. an a few miles later when i pulled in my driveway my headlights blew out. the bulbs were busted.

but the alternator thats in my car now is what came with the jdm motor i got a couple years back.

[AutostradaVR4]

Originally Posted by elon3kgtslowner

when it was overcharging did your lights flicker really bright, both in-dash and the forward pointing ones?

Nope, no flicker at all. The headlights/highbeams in that car are crazy bright anyways though, so i may not have noticed if they were a little brighter.

anyway, gool luck with the new alternator install

[elon3kgtslowner]

yeah thats what happenned to mine. the voltage regulator was shot and it would put out different voltages at different rpms. i didn't know you had a multimeter and a battery charger though, thats a big help. i wish you good luck on the new one too. napa should give you a good warranty for the part. haha i just read my last post again and i didn't do a very good job rephrasing.

[Morphius289]

Wow. I wish I had your luck. When my alternator went, it went hard. As in I had around 15 seconds between when I noticed voltage was low and the time that the car died.

[StealthModifier]

i got the alternator pulled last night. ive got good at it, only took me 30 minutes . anyways i gotta pick up the new one at 3. they said it had a 3 year warranty. hopefully this one will put out a lot more volts.

[StealthModifier]

got the new alernator put in an its doin alright. voltage stays around 12.5 with lights on.