Alternator and Battery Problems

[5LugFoxFanatic]

I have a digital amp/batt gauge that plugs into my cigarette lighter and I have some concerns. About 5 years ago I replaced my stock alt with a Powermaster one wire hook up alt from summit. I think it is either 130 or 140 amps. So When I am driving, I am usually at 14.0-14.2. With the car shut off, I am right around 12 volts so that's good. The battery is a brand new interstate.

Here's the problem. I was driving last night so naturally I turned the headlamps and fogs on and my amps dropped to 13.1-13.3. I stopped at a light and at idle, it dropped to around 12.5 amps!

This is not good. Is my alt going out or is this normal. I just pulled my car out of storage and do not remember it doing this before, not a drastic change like this dipping below 13 amps. What is wrong? Hopefully the alt is not dying.

 

[HISSIN50]

i take it this was at idle? what is your idle speed? did it go back up if you raised the revs a couple hundred RPM?

if you have doubts, you can have a parts store check the system out for free.

i would charge the battery up, so you know it is good to go and clean all the battery and ground connections - after sitting all winter, they might have corroded.

good luck.

 

[5LugFoxFanatic]

i take it this was at idle? what is your idle speed? did it go back up if you raised the revs a couple hundred RPM?

if you have doubts, you can have a parts store check the system out for free.

i would charge the battery up, so you know it is good to go and clean all the battery and ground connections - after sitting all winter, they might have corroded.

good luck.

idle speed is around 650-750 rpms. I should bring it in and have it checked out. I just thought that it sounded low at 12.5 amps.

 

[Stang8URMPRT]

I had the same problems when I put my Alterstart 150 amp 3G on. It turned out being the negative battery terminal. My dad (previous owner) put one of those quick disconnect battery terminals on it, and it wasn't tight at all.. Put a real terminal on it, and all problems were fixed.. Check grounds, probably your problem.

 

[HISSIN50]

looks like Nick and i agree.

one last thing: i would check the voltage across the battery terminals at a given time and note how it compares with the voltmeter you are using in the cig lighter. often times, a volt meter gauge in the car (permanent) can read lower than the battery or alternator.

i am thinking that you will be reading fine with a charged battery, clean connections and using a meter on the battery. but check it out at the battery.

good luck.

 

[DMAN302]

UD pullies can play a role at idle..larger pulley on alternator can slow the charging right down..mine does much the same thing at idle.

 

[5LugFoxFanatic]

I will clean off the posts and terminals. I just replaced the terminals last year, but hey with a MN winter anything can happen. Thanks fellas.