Weird electrical

[87redgt]

So in the past weeks my car has developed a little problem. When driving with my headlights on my stereo is fine until I come to a stop then my stereo goes out like it has no power. If I give it gas it comes back on. Also there are times when my stereo wont come on at all with the headlights on. At the same time my car started developing a little miss in the 4500 and up rpm range. The miss is really bad when my stereo wont come on at all or if its cold outside. My thinking is that it might be the altenator causing these problems. Is my thinking right or am I missing something?

 

[seedeezy]

What do you mean by a little miss in the 4500 rpm? Does it feel like a rev limiter? Of like your distributor has water vapor in it and the spark is fading on you.

I would hook a volt meter up to your battery, start your car and see what voltage output is when the thing is all the way warm. It should be 14.3-.5 without anything on at idle. If you have underdrive pulley's the alternator might be underdriven more than it wants to be at idle when running alot of electrical goop.

 

[87redgt]

Yea, sometimes it'll feel like I have a rev-limiter and not want to go past a certain rpm. It will just studder and not go anywhere. I was thinking it might be the altenator because it ran fine for the past 6 months and it just started doing this about a month ago.

 

[HISSIN50]

Do your turn signals or HVAC blower act weird as well?

 

[seedeezy]

That HEI coil hates being at anything under 12Volts, I can contest to that from the little bit of accidental experience I have in that area. Low voltage will give you high rpm ignition issues before any other issues reveal themselves. My dad terms this 'blowing out the spark' and litterally thats what is happening, the cylinders are doing more than your ignition can keep up with so the spark just fails to make the jounrney accross to the other side and light the cylinder off at high loads and high piston speeds. Since you haven't messed with any wiring in your car I would guess that your alternator isn't up to snuff.

 

[jrichker]

Most major auto parts stores can test the alternator and charging system for free with the alternator in the car.

If you already have the alternator off the car, they can check it on their tester for free as well.

 

[87redgt]

So, I think its the altenator and if it is I have a question. Can I just get an altenator for an automatic? I mean its 75 amps instead of 65 for the manual and its like $10 cheaper. Will it fit the same and work better?

 

[seedeezy]

The harness is the same so it will physically go right on. I would go with my gut feeling on that one. I honestly didnt know their was a difference and I have put an auto alternator on a stick shift ride and everything was good.

 

[HISSIN50]

Where did you get the info about the auto vs manual alternator?

At least have the thing tested before throwing money at parts you might not need (especially since you'll want to do a 3G upgrade down the line).

 

[87redgt]

Where did you get the info about the auto vs manual alternator?

At least have the thing tested before throwing money at parts you might not need (especially since you'll want to do a 3G upgrade down the line).

I'm going test it, but I have to take it out. And where I found the difference between auto vs. manual is right off the kragen website.

 

[HISSIN50]

I'm going test it, but I have to take it out. And where I found the difference between auto vs. manual is right off the kragen website.

Not that it matters, but autos and manuals came with the same alt as far as I know.