Alternator acting crazy... voltage drops and spikes

 

Silver Member
Username: Baalpeteor

Post Number: 126
Registered: Oct-07
I put a 200 amp alt in the other day, and it was working swell.. One day when i was riding 75 or so mph down the highway and had a song up high with real low frequencies super loud (since i actually have the top hardest hitting 6 or so songs on this forum), it was showing the red battery light that shows when you cut your alt wires and run off battery, or just run off battery and dont start the engine. I turned it down and it went away. Keep in mind im running just 1100 watts on a sub and like 200 or so on 2 6x9's. I believe its a wiring thing and ill check into it friday, just wanted to see what you guys think or if you had the same problem....

The wiring is the standard 12 or whatever super small gauge (94 sunbird LE) that go from alt to starter, and i put a 0 gauge (it was cut down at the end to fit into a 4 gauge ring terminal) that goes from the alt to a stinger digital bat terminal on top of a yellow top battery.. it has 2 0 gauge outputs.. the other goes to the dist block and to amp and cap.


Here's how it is now.. I ride around.. while im accelerating anything from 1 mph or higher basically, it will jump to 14 volts or higher on the cap (so the system is running this totally) and lights are bright and dash, soon as I get below 15 or 10 or so and start decreasing it starts to drop and dim, and when i finally stop im at like 10.5 or lower volts.. around that vicinity... and everthing dims.. headlights and dash. i cant keep the system up b/c it will cut the radio off if its too high due to low voltage. Soon as I accelerate again it goes up. Had the antilock light come on b/c the voltage was soo low. I will get my mechanic to try his hardest to fit 0 gauge onto the starter but it will be hard...
 

Silver Member
Username: Baalpeteor

Post Number: 128
Registered: Oct-07
well me and my personal mechanic just took a look at it tonight in the dark... moved the wires around (i have the small 14 or whatever gauge stock and 0 gauge on it) and he thought perhaps b/c it was rubbing and touching the metal brace that could be it. It was not.. we will switch the wires out and just have the 0 gauge some time this week...

as for now, the headlights dim, the inside lights and all. its like even when parked with no radio they dim and flicker
 

Gold Member
Username: Nd4spd18

Northwest PA

Post Number: 7091
Registered: Jul-06
What brand of alternator is that. Either it's a POS or you've got the wrong pulley on it.
 

Silver Member
Username: Baalpeteor

Post Number: 129
Registered: Oct-07
motor city remanufacturing. cost me 250 or so roughly for 200 amp with like 10 or 15% off code. It was working swell though. Everything worked swell on first until I put on my hardest hitting, which is the hardest hitting sonsg i've made the hardest hitting (thanks to my dj equipment) and some are screwed, so they reach prob 10 or 15 hz or aroudn that low and are loud, which means a huge power drainage. Thats when the battery light started showing and all hell broke loose. Its a new belt also. the 15 or so gauge has broke twice before with an 110 amp alternator... and the 0 gauge (cut for 4 gauge at the alternator screw terminal) goes from alt to bat so once i put that to starter we shall see
 

Gold Member
Username: Adddisorder

Palm Beach, Florida

Post Number: 6127
Registered: Jan-06
you dont need to upgrade the wire to the starter search for the big 3 and just do that.

just sounds like your alt isnt putting out and idle voltage.
 

Gold Member
Username: Nd4spd18

Northwest PA

Post Number: 7125
Registered: Jul-06
^^^^ Exactly, and it's usually a problem with the pulley or belt. Is the pulley the same size as the stock one? If not, you need a different belt.
 

Silver Member
Username: Baalpeteor

Post Number: 130
Registered: Oct-07
hmm I will have to go out and compare them today/tomorrow. Thing is though would it matter that for the first 3 or so days the voltage was ok? It gave off 12 at idle, and on acceleration. It just started acting crazy after being on the highway and having that super low hz song on blast and the battery light starting showing on each low note
 

Gold Member
Username: Nd4spd18

Northwest PA

Post Number: 7132
Registered: Jul-06
Does it work fine when your not blasting that song? If so your probably just drawing too much current.
 

Silver Member
Username: Baalpeteor

Post Number: 131
Registered: Oct-07
nah its like the alternator stops running completely. Only reason I know it runs is the battery light doesn't come on. The A/c turns low, the lights everything dim, and it stutters like flickers. if the radio is on then it will be ok, but once i do crank it up my needle will jump (speedo ) around and the antilock light will come on etc... the same thing it would do on my old alt if the music was too loud and it drew too much current. It has to be that wire to the starter. I just checked the belt and all. The belt I put on nomore than 2 months ago
 

Silver Member
Username: Baalpeteor

Post Number: 132
Registered: Oct-07
we put a ring terminal on the stock power wire from alt to starter today... as it never had one... didn't help. I will check the belt tomorrow.. it is nomore than a month or so old. The pulley may be differ, but its strange because for 2 or so days of putting it on i had no alt problems like this until now all of a sudden without messing under the hood at all. We did not run the 4 gauge from alt to starter as I hoped, as he said the stock power wire from alt to starter went into a harness... and we didn't know where it went so running the wire from alt to starter straight would not work. I already have 0 gauge from alt to battery straight (via stinger bat post)

for the big 3... what is the 3 wires needing upgrading? i know alt to bat and alt to starter... what else?
and can I keep stock in place.. and just "tuck it in" or keep it connected? I already have 0 gauge from alt to bat, and could maybe put the 4 gauge alt to starter and keep the original one on their.... but now i highly doubt iits a wiring problem now.. but i still need bigger wires..

I will call motor city reman tomorrow.. they have on their page the biggest problem people have is this and they have fixes . they say some of their alts aren't direct replacement they require other things as they are belt and wire sensitive
 

Platinum Member
Username: Th3pwn3r

Post Number:...

Post Number: 7752
Registered: Jul-06
"for the big 3... what is the 3 wires needing upgrading? i know alt to bat and alt to starter... what else? "

You do not need to upgrade alt to starter. You need to upgrade alt to battery, battery to chassis, alt ground to chassis.
 

Silver Member
Username: Baalpeteor

Post Number: 133
Registered: Oct-07
ya it seems to have been a pulley Issue. The current alt was 2.5", and the new 2". It would be wise to get a smaller belt (my mechanic keeps on crying and bsing like a gurl when it comes to things like this.. he keeps saying how hard it is to get a smaller belt like i have no motivation :-p ) .

I realized how loose the belt was and how it just slipped on the new alt, versus my high performance which took a good pull to get it over it, but it was just right. I could change pulleys but I am giving this car to my dad, and im getting an older altima, so I will sell this 200 amp alt on ebay or something. It fits sunbirds, cavaliers, all that
 

Platinum Member
Username: Stateprop486

PA

Post Number: 1382
Registered: Jan-08
damn that sucks man, u didnt get good use out of that h/o alt. im running on a stock 80 amp alt with big 3 done. Im running a zx1000.1 for subs and a zx250.2 for comps and i never had any problems what so ever...
 

Silver Member
Username: Baalpeteor

Post Number: 134
Registered: Oct-07
I never got around to doing the big 3. I wouldn't even know how to upgrade the alt to chasis ground as I have that plug with 3 wires... the ground is part of that. Seems I couldn't reground that one.

Im going to sell the alt ... ima post here and on the jbody forums (just for sunbirds) as the alt is like 5 or 6 days old today.. and it was only in use for like 4 days after I took it off and slapped my old new high performance one back on... 120 amps from autozone (prob 2 months old)
 

Gold Member
Username: Somedonniedude

Illinois United States

Post Number: 1369
Registered: May-07
Did you say your ground wires were breaking? Are they brittle? I would get that fixed regardless if your selling it or whatnot, if thats the case.

Make sure your belt tensioner is in good condition too, but the belt is what seems to be the issue here.
 

Gold Member
Username: Nd4spd18

Northwest PA

Post Number: 7270
Registered: Jul-06
Your stock wires have nothing to do with the big 3.
 

Silver Member
Username: Baalpeteor

Post Number: 138
Registered: Oct-07
nah but I see that the stock stays. The wire that was breaking was the power wire from alt to starter. It is real small, prob like 15 gauge or so and is made of that primary wire you find in auto places.. the kind that's made up of like 9 or so strands of thick copper wire if even that many.

it has:
1.) deteriorated off the starter (with the green nasty acidy paste)
2.) snapped in 2 (had to put a wire nut.. this all happened after i put my system on)

perhaps if I had did the big 3 now I would not have even needed the 200 amp alt yet but anyways... im getting a 93 nissan altima so
« Previous Thread Next Thread »



Main Forums

Today's Posts

Forum Help

Follow Us