What size alternator does our cars have? I researched our cars and found 45 amp and 95 amp alternators. The guy at auto zone said he thinks it is a 95 amp. Then I was like, I just installed a 2600watt system in my car and my car bogs out when Im crankin the system. So his stupid responce was “I dont know, maby you could check JCWhitney or something”. I was thinking in my head, O hell no, he didnt just refer to JCShitney. But anyhow, what is the biggest alternator that we can fit on our cars. If I dont get one soon, I’m gonna end up messin up the one I have and my battery. If my alternator goes, It could cause a spike in voltage and fry some of my electronics. Thanks


The charging system consists of the:

l Generator (GEN) (10300).

l Integral voltage regulator (VR) (10316).

The generator provides 95 amps on the coupe and 75 amps on the sedan.

That is from the service CD. I dont know how he got a 45 amp alternator.

I don’t know how much extra stuff you have running, but I’ve got an amp with sub and upgraded head unit along with a few neon accesories and I’m running a stock spec alternator. I just replaced the alt and battery(upgraded) this summer and had no ill effects on the electronics when alt went bad. I’m a li’l mad though, 'cause now I get a battery light at higher RPM’s and it won’t stop no matter what I do… I know this doesn’t tell you anything about the voltage, but basically the point is to say the stocker should be okay. But if you’re worried about it…replace it. It’s not that bad once you know what you’re doing. And if you have the right tool. :slight_smile:

  • Darron

Yea, back a while ago I made a post on here about replacing the serpentine belt, still havent done that. Well, my car is starting to act, well gay. I know that this is partially the alternator b/c I had my system cranking way up, in neutral coming up to a turn that goes to a stop sign. I was driving along just got over the top of a hill at 40mph. I go to take the corner and it was kinda hard to steer. I was thinking wtf, i look down at the guage benzel and all my warning lights are on, my freaking car stalled. Also if Im at a red light sitting, my rpms drop dramaticlly now. I also noticed a big decrease in my miles per gallon. There is an Alternators and Starters specialist about 7-8 min from my house, im gonna run there after school, if they dont have it, they can build it (hoping it wont be to much) figuering around $140-$170 tops. Its deff not my plugs, just replaced them not to long ago. Im gonna get a yellow top battery (match my car, stereo system) to help and stick my stock one in my trunk.

Just a heads-up, you’re gonna have to modify your terminal connectors to have the yellow top work properly. It took me about an hour and a half to install mine, but I didn’t have the proper tools around either. I bought some different connectors that reached farther to get the positive terminal, then modified the negative, but will soon enough replace that one also.

  • Darron

Your system is not really 2600 watts.

Using the equation:

current = power / voltage

2600 / about 12 volts = about 200 amps

That’s assuming the amp is 100 percent efficient, which is impossible…so it would be even higher current.

I hope you don’t mean you are going to try and run your stock battery in parallel with a yellow top. You have to have identical batteries to do that.

Foos…it sounds like your voltage regulator is not regulating.

I know my system isnt 2,600 watts, Its just (2) 1000 watt MAX sub amps, and (1) 560 watt MAX speaker amp, that would be with everything briged but yea, it still comes out to 2,560 watts MAX. Its just how every other car that I have seen rated so I decided to go by the Combined MAX to figure out the wattage.

Why couldnt I run the batteries like that, as far as I know, the batteries just have to be the same voltage. I know that the Yellow Top has less resistance allowing electronics to pull power better, among other things, but if it comes to that, Ill just put the Yellow Top in and be done w/ it.

If the batteries are not matched, the one will the lower charge will always try to pull current from the one with the higher charge. They will also not charge equally. It will reduce the life of your new battery. If your old battery is crappy enough it could blow up your new battery.

I would go with the yellow top and call it a day.


Man, battery acid sucks. Even if BbbyBld were wrong, I still wouldn’t do it if that were a possiblity.

Bbby…ideas how I could fix that?

  • Darron

I once installed a new alternator, and it started doing that. I had to exchange it for a new one. In my situation I could not replace the regulator since it was inside the alternator.

When having a high power (2400watts rms and up!) the battery has nothing to do with it , unless the car is off and you have a second battery isolated . The Stock zx2 95 amp alternator is not enough to even drive one subwoofer amp with a 40amp fuse! The headlights will only dim!!!
What you need is a high out put alternator . You can purchase a rebuilt 200amp alternator from for just under $200 shipped anywhere in he usa ! If you have any questions about how to remove the alternator I’m here ! Check out my car at my cardomain site in my signature , I’m running 1200rms+2400watts peak !

Instead of trying to make the alternator work harder …make it work smarter. Get yourself a 1 farad capacitor, you can find them at your local stereo shop or even online - Crutchfield has some good deals - if your not privy how to charge/load a capacitor then have it profesionally installed. You don’t want to have that blow up on you. I used to manage a car stereo shop back in the day , so if you have questions on installing and things of that nature give me a shout.

The capasitor is a really good idea. You can pick them put at HAM fest for $3 for 2. Install them yourself.

Actually the capacitor that I am speaking of can be found usually only at car stereo shops. This is a link to show what i am talking about. I wish these things ran $3. I would be a happy happy man. :smiley: It is always a smart option to run one of these when you run alot of power. They go inline on your power cable and store up the power so when your amps need it they feed on it instead of the battery/alternator.

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the amps of our alternator is 95 amps

Has anyone tried an MSD APS Alternator on their ZX2? They have a modular alternator pully system. It like having a wide selection of ODP’s to choose from. Granted I think only 2 of the pulleys they offer would work with a zetec. I am not sure which one we would use with the Zetec. But it is a modular mounting system as well.

But all of the MSD alternators are over 100 amps as far as I can tell.

Consider getting a custom one made. I had a 200 amp one made and had only very small mods to make it work in the Z. I had to weld on a sleve to make it butt up against the support where the top screw goes in, and I had to use a longer belt.

Solved alot of issues for me.