HELP Charging System

[ZIMxxZUM]

Hey guys,

Now I know there’s no doubt the Terminator is infamous for having alternator problems. Lately I’ve been noticing that when i start my car for the first time and turn on the ignition, all of the lights come on. (Battery, ABS etc). However, after driving it around and shutting off the car, I have noticed that when I turn the ignition on again, all of the lights come on except for the battery light. This has puzzled me for some time.

I checked the volts when starting the car and it starts off normal 14.0-14.2. After a few minutes the volts drop to 13.1 and as low as 12.8. When starting the car when the battery light is off, the volts stay low. I’m assuming that if the alternator is bad, the volts would start off low. I’ve searched and have hardly come up with any results.

My question to you guys is if any of you have had this same problem and if you did, what did you do to fix it. I’m really trying to avoid buying another alternator if I don’t have to; especially if the problem is something else. I’m currently running a PA performance 170 amp alternator.

Any input is appreciated. Thanks

 

[ccq8le]

I am not sure I fully understand.

You're saying if the battery light is not on when turning the ignition on than the Alternator never seems to kick in to the 14 volts? And also saying this only happens like after initially running the car? (like when the car is hot?)

Are you running factory battery wiring?

Does the issue seem to be more so when the weather is hot too?

 

[ZIMxxZUM]

I am not sure I fully understand.

You're saying if the battery light is not on when turning the ignition on than the Alternator never seems to kick in to the 14 volts? And also saying this only happens like after initially running the car? (like when the car is hot?)

Are you running factory battery wiring?

Does the issue seem to be more so when the weather is hot too?

Yes, when the battery light is off, the volts never go 14+ volts.

After the first start of the day, or if the car has been sitting a while, the light will not turn back on. if I were to shut it off then go to start it back up again the light will not come on. However it will sporadically turn back on but It’s pretty random

It’s been happening for about 4-6 months and it just recently started getting hot here in SoCal

I also have the power cable upgrade from PA performance. I forgot to mention that

It sounds like faulty connection but I’m not sure where that faulty connection is

 

[ccq8le]

I would check the alternator connection first, and definitely clean it up and check the nut for corrosion. After that check the other connections and the battery terminals.

I have been through Charging Woes myself and it can be discouraging for sure. I haven't much monitored the Batt light when turning the ignition on. I wish I had more for you.

Hopefully someone chimes in with something better.

 

[big dad]

The very first thing you should do is check the battery starting with the specific gravity of each cell if it's a lead acid type battery. Then do a load test.

If the gravity readings between each cell is 50 points or greater between any of the cells the battery is bad.

When diagnosing a charging/starting system problem you always need to check the condition of the battery first then proceed to charging system and related components.

 

[MG0h3]

If I’m reading this correctly, we’re only talking about the light being on/off with the key on/engine off...correct?


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[ZIMxxZUM]

The very first thing you should do is check the battery starting with the specific gravity of each cell if it's a lead acid type battery. Then do a load test.

If the gravity readings between each cell is 50 points or greater between any of the cells the battery is bad.

When diagnosing a charging/starting system problem you always need to check the condition of the battery first then proceed to charging system and related components.

The battery is new. About 2-3 weeks. Even after putting in a new battery it still did the same thing

 

[ZIMxxZUM]

If I’m reading this correctly, we’re only talking about the light being on/off with the key on/engine off...correct?


Sent from my iPhone using svtperformance.com

Yes but I’ve see a correlation with volts being low when the light is off

 

[ZIMxxZUM]

Thanks for the input guys. I’ll look into the connections on my next days off. My car has 200k miles and this is the one major issue I’ve had with it.......Alternator problems left and right

 

[94 Cobra R]

How are you checking voltage?


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[ZIMxxZUM]

How are you checking voltage?


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Using a voltmeter on the battery terminals

 

[*Jay*]

If you havent already get the service manual.

SVT Documents

Then go to page 3294 and follow "Pinpoint Test P" THE CHARGING SYSTEM WARNING INDICATOR
IS NEVER/ALWAYS ON

You can also go straight to section 414-00: Charging System, for more issues than just an indicator light. See below...

 

[hotcobra03]

I had issues with ground wire at engine mount.

stud was broken but still hanging..

during testing volts..I used jumper wire from battery to engine and volts came back up..

 

[*Jay*]

I had issues with ground wire at engine mount.

stud was broken but still hanging..

during testing volts..I used jumper wire from battery to engine and volts came back up..

This is why I recommend that anyone with voltage issues goes through all of the associated wiring/straps for battery-chassis-motor grounding and 12v lines from the battery-power distro lug-alternator-starter. Im pretty sure my car use to have a trunk mount battery and my wiring was hosed, had to redo everything I listed above and still need at least one more chassis-motor ground that I found missing this year.