Electical Gremlin

[vicLover]

Now that its getting cold, this new prob is worrying me. I converted to a 3g alternator. I have a 175amp fuse right at the pos. battery terminal coming from the back of the alternator. I have 2 gauge wire going to the starter, the ground and from the solenoid to the positive post to the battery. Now the charge cable from the alternator is a 4 gauge wire. None of the connections are loose, I've triple checked. I've had the alternator checked 3 times previously. Alternator: Duralast Battery: Duralast. All cables, Duralast.
Problem: when the car is put in gear the lights get dimmer. When I accelerate the lights get brighter. When the radio's thumpin, all the lights dim when the bass hits. I don't know where to start and I've searched here and nothing. I know I did something retarded, but a retard wouldn't know what, if you get my drift :err:

[86VickyLX]

Now that its getting cold, this new prob is worrying me. I converted to a 3g alternator. I have a 175amp fuse right at the pos. battery terminal coming from the back of the alternator. I have 2 gauge wire going to the starter, the ground and from the solenoid to the positive post to the battery. Now the charge cable from the alternator is a 4 gauge wire. None of the connections are loose, I've triple checked. I've had the alternator checked 3 times previously. Alternator: Duralast Battery: Duralast. All cables, Duralast.
Problem: when the car is put in gear the lights get dimmer. When I accelerate the lights get brighter. When the radio's thumpin, all the lights dim when the bass hits. I don't know where to start and I've searched here and nothing. I know I did something retarded, but a retard wouldn't know what, if you get my drift :err:

Sounds like me with my regular alternator. What size is the pulley, is it a bigger diameter than the original? It's possible that it's no spinning fast enough to put out the right volts at idle. But you shouldn't get a dimming, unless you have like every other thing that draws current on, and you're at a stop, then yes. But the idle voltage being better is one of the reasons why people go to the 3G alternator.

[gadget73]

Depending how much load is on the electrical system, that might be perfectly normal. I would suggest upgrading the ground cable from the engine to the body if you haven't already.

[cld783]

does it do it without the stereo hooked up?? do you currently use a cap? what size stereo are we talking??

[vicLover]

By better ground cable, do you mean a new one, cause a 2 gauge is the biggest (I thought) there is? My stereo is an aftermarket Pioneer (there $150ish model), Pioneer 6x9's, 4x2's up front and no amp. I did get a pretty big (~20 inches or so) electric fan out of a 2000 looking model Grand Marq, from the junk yard. Looked like a loaded edition, forgot to get a vin number or anything. Now the ground for the fan I'm running straight to the ground post at the battery. I also have a Hayden 16 inch fan in front of the radiator blowing back towards the engine, also grounded at the battery. At idle I am getting 14.5 or so volts and thats with both fans on, blower on high, stereo at moderate volume, no defrost though, so I know its charging. Its just annoying when I go from Park to Drive the lights get noticeably dimmer (without the stereo on), they flicker with bass notes, and they get brighter and sustain brightness when I give it the gas. Don't seem like thats normal to me with a 3G alt.

[Wray-Wray]

seems like you got a kick ass load on that G3 with BOTH fans and such it might be normal i agree with gadget about the new ground cable and cleaning all connections it makes, really well to start with

[86GmLsCoupe]

I'd have to agree with what others are suggesting. Many do "the big three" upgrade along with the 3G upgrade.

Definition: the "Big Three" upgrade means improving the current capacity of three cables: 1) alternator positive to battery positive, 2) battery negative to chassis, and 3) engine ground to chassis. (the12volt.com).http://www.the12volt.com/installbay/...TID~73496~PN~1

[gadget73]

By better ground cable, do you mean a new one, cause a 2 gauge is the biggest (I thought) there is? .

I'd have to agree with what others are suggesting. Many do "the big three" upgrade along with the 3G upgrade.

Definition: the "Big Three" upgrade means improving the current capacity of three cables: 1) alternator positive to battery positive, 2) battery negative to chassis, and 3) engine ground to chassis. (the12volt.com).http://www.the12volt.com/installbay/...TID~73496~PN~1

What he said. The battery to engine ground at 2 ga is fine, but there is a dinky little 8 or 10 ga wire at the back of the motor that needs to be upgraded too. The electrical path for the ground is basically battery > engine > car. If the cable from the engine to the body is in bad shape, it will cause low voltage inside no matter how much alternator you have under the hood. Some cars (mine for example) had no battery to body connection, so you're entirely reliant on the engine to body connection.

[1987cp]

My suggestion? Remove the aftermarket amplifier. That'll free up lots more juice for the more necessary functions.