Battery Light Coming On??

[bjtheman1]

Cleaned the terminals well last week and made sure no connections were loose from the alternator. Battery light still on.

Soo......last remanufactured alternator I had=battery light would come on but go off when I increased rpms.

Now...new PA performance alternator=battery light comes on and stays on.



Here's all my readings.

With my Voltage Meter:
Car Off Battery Voltage - 13.8
Voltage from Alternator - 13.6

Car on w/heater & headlights on:
Battery Voltage - 15.5V
Alternator Voltage - 15.6V

With Battery Load Tester:
Battery Load-Good/Green

Charging System Test with Car on and acces. off-Good

Charging System Test with Car on and headlights & heater on- Good

[KBScobravert]

Charge cable to the battery, what size?
Where is your battery located?
What size is your ground and were is it routed to and from?

If you are using the factory wiring with a larger alternator you are gonna have problems. Fuseable link could be toast also.

I suggest getting a hold of Tony Candela's Automotive Wiring and Electrical Systems

[91cavgt]

Cleaned the terminals well last week and made sure no connections were loose from the alternator. Battery light still on.

Soo......last remanufactured alternator I had=battery light would come on but go off when I increased rpms.

Now...new PA performance alternator=battery light comes on and stays on.



Here's all my readings.

With my Voltage Meter:
Car Off Battery Voltage - 13.8
Voltage from Alternator - 13.6

Car on w/heater & headlights on:
Battery Voltage - 15.5V
Alternator Voltage - 15.6V

With Battery Load Tester:
Battery Load-Good/Green

Charging System Test with Car on and acces. off-Good

Charging System Test with Car on and headlights & heater on- Good

Where are you taking your voltage readings at? That voltage is pretty high. Is that internally or externally regulated?

I'd do a voltage drop test on your cables to see if you've got a bad cable somewhere giving you some problems. Don't just check the hot wires though, check your ground wires too, and not just the primary ground for the battery. You need to check the block to chassis ground as well as all the other main ground wires too.

[HOOCBB]

Where are you taking your voltage readings at? That voltage is pretty high. Is that internally or externally regulated?

I'd do a voltage drop test on your cables to see if you've got a bad cable somewhere giving you some problems. Don't just check the hot wires though, check your ground wires too, and not just the primary ground for the battery. You need to check the block to chassis ground as well as all the other main ground wires too.

I agree that 13.8V with the engine off seems a little high, but it's not indicative of a battery cable issue. Battery cable issues USUALLY show up as a no-start/slow-start condition.

Is the battery light the only symptom? What vehicle?

[lowthreeohz]

bad cable wouldn't read high voltages on the battery side...

[bjtheman1]

Charge cable to the battery, what size?
Where is your battery located?
What size is your ground and were is it routed to and from?

If you are using the factory wiring with a larger alternator you are gonna have problems. Fuseable link could be toast also.

I suggest getting a hold of Tony Candela's Automotive Wiring and Electrical Systems

Stock Size
Far left corner of compartment
Not sure on size, I believe it's routed to part of my chasis right by it

I do have the PA Performance Power Wire coming so I hope that might work

[bjtheman1]

Where are you taking your voltage readings at? That voltage is pretty high. Is that internally or externally regulated?

I'd do a voltage drop test on your cables to see if you've got a bad cable somewhere giving you some problems. Don't just check the hot wires though, check your ground wires too, and not just the primary ground for the battery. You need to check the block to chassis ground as well as all the other main ground wires too.

All readings externally. I'll keep checking around

[bjtheman1]

I agree that 13.8V with the engine off seems a little high, but it's not indicative of a battery cable issue. Battery cable issues USUALLY show up as a no-start/slow-start condition.

Is the battery light the only symptom? What vehicle?

2007 Roush 427R

And yes, just the battery light. Everything seems to be working fine

[1fast4]

Had almost same issue on my old F150 I picked up a few months ago.
Turned out there was a short (break)in a wire going to the starter solenoid.
Only found it by checking voltage on both ends of every wire. Replaced wire and no issue no more.

Just a thought. GL with the issue

[Clifton]

Overcharging.

[EW]

15.6V am too much.

[bjtheman1]

Well, put on the PA Performance Power Wire today and battery light still haunts me!

[krazy kris]

Well, put on the PA Performance Power Wire today and battery light still haunts me!

Reset the Computer

[bjtheman1]

Reset the Computer

Did this too, still with no luck. There's still many more things I need to check it's just very annoying trying to figure out this damn battery light!

[krazy kris]

Sets that shits on fire