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Hi guys im sure somebody has posted this before but ive checked and cant find it so im asking once more. im having problems with voltage drops in my truck. i know this is somewhat normal but today on the way into work it droped to 10.5 now all i really want to know is if my new alternator will fix this problem?

potentially.........it depends on your power demands and the new alternator

well the new alternator is an excessive amperage large case 200 amp what else can i do?

upgrade your alt. wiring, ever try cramming a potato through a straw?

lol no um putting the new alternator in tonight and im upgrading all the wire to 4 ga any suggestions? tips? how much of a pain in the ass is this going to be?

if the voltage drops to 10VDC, there are two reasons.
one is a bad stock alternator, or two is a bad battery (or both) since with a normal lead acid battery, if it's drained below about 10 volts, you're just about guaranteed to have irreversable damage to the battery cells, so it'll never go to 12 volts again.

anyway, fix is to install the new alternator, and while doing so, upgrade the "big 3" with 2AWG cable (for a 200A alt.) and replace the old battery with a new high-CCA starter battery (from auto zone or sears etc) or switch to an optima at that point. the optima deep cycles will allow you to fully "deep cycle" the batteries to 0 volts and recharge them without killing the batteries. That's one of their main benefits.

Bwcad1 wrote:lol no um putting the new alternator in tonight and im upgrading all the wire to 4 ga any suggestions? tips? how much of a pain in the ass is this going to be?

200amp alt might want larger than 4ga, more like 2ga or 1/0 ga

Isn't 4ga capacity 150amp? I dont know, someone correct me.

Well I talked to the stereo guy around here and Devin at sinister audio and both said 4 gauge would be fine. Im also just going to add the wire not swap factory and new when I do the big 3. Anyone done this on a blazer? How difficult is it? Not worried about the alternator when my original died my truck died at AutoZone and I swapped it out right in the parking lot there lol.

I would lean towards 1/0 since 2 Ga connectors are so hard to find...

they're both wrong. 200A is more than the capacity of 4AWG at peak by 25%. You need to use 2AWG minimum for a 200A alternator unless you're absolutely sure you'll never draw more than 150A of current between the car and the stereo, at any time.