What purpose does the Battery Saver have?

[penske2584]

One day I get in my 96 xlt and the battery light is on and battery is half way down. What does the Battery Saver do? Cut circuits on a relay?

Issue:
Alternator isnt recognizing low battery and stays at 12.7 volts not up to 14v to charge it.

I took the battery in and the store charged it and tested it. It was 847/850 cca and bought in 01/13. So... I got home and installed it. Still at 1/2 charge on the gauge and battery light on.

My guess is alternator. Maybe a ground. Wondering what the battery saver has to do with the system. The store wont check alternator until the battery is charged.

 

[koda2000]

the battery saver relays main purpose is to turn off interior lights if you leave your door open for a long period of time, so your battery isn't drained. it's supposed to turn off the interior lights after 10-40 minutes. it has nothing to do with your alternator.

a fully charged battery should show around 12.6 volts static. the alternator should show around 14.3 volts at the battery with engine running. cranking amps are what starts your engine (has nothing to do with static voltage). the gauge on our dash is an idiot light with a needle. it usually registers about dead center and it has no numbers on it. it's not a voltage gauge. if your BATT light comes on, your alternator is not charging your battery and your vehicle is running off the battery, which will eventually drain it. if you're not seeing 14+ volts at the battery with the engine running, you have an alternator issue. it could be internal diodes, the voltage regulator, wiring or a fuse problem. if your BATT light bulb doesn't work your voltage regulator will not get turned ON and your battery will not be charged.

 

[penske2584]

I realized I pulled both diodes in the power distro box. Just read chiltons diagnostics and they dont recommend removing them for long. What will happen if the diodes are out of block for say 30 mins or 1 hr? They run PCM and ABS.

Next day is when I started to have the battery issue.

 

[koda2000]

I realized I pulled both diodes in the power distro box. Just read chiltons diagnostics and they dont recommend removing them for long. What will happen if the diodes are out of block for say 30 mins or 1 hr? They run PCM and ABS.

Next day is when I started to have the battery issue.

i'm not sure what you're referring to by "diodes in the distribution box". All my vehicles are newer, but the only things in the distribution box are relays and fuses. Diodes only allow current to flow in one direction. My guess is that, whatever you've done, you've fried your alternator or its voltage regulator. Diagnostic testing (with a volt meter) will be required to figure out why your battery isn't getting charged.

a good place to start is with a wiring diagram of the charging system...

free wiring diagrams:
I would recommend getting your specific model wiring diagram. You can find one at http://search.ebscohost.com/. Use RRCC and rebsco when signing in. FYI: Some people have reported that the user id and pw are case sensitive.

 

[penske2584]

i'm not sure what you're referring to .....

Thanks for the help. Diodes only go into the box one way. Not sure how I would have fried the alternator. All relays and fuses are correct. The problems I am having could be from short circuits I think with open wires or bad grounds.

yes I have access to ebscohost and get Chiltons and Auto Reference. I will take it in and have it tested. I only have a digital multimeter not able to handle the amps.

Here is what my Distro Box looks like in someone elses vehicle.

 

[penske2584]

Problem Resolved! Alternator is just slightly above middle. Charging system is working. I resorted to new updated diagram of fuses and relays. I cleaned 3 grounds in engine compartment. Chiltons had higher amp fuses so I replaced a "15a stock" with a 20a. thanks for some help!

 

[penske2584]

Still working great. No issues since. Does it make sense to upgrade the fuses? To me having too many amps could start things on fire.

 

[koda2000]

fuses are there to protect circuits. going from a 15a to a 20a shouldn't hurt anything if it solves your problem. that being said you shouldn't replace a 7a fuse with a 30a.

 

[bill06447]

... the gauge on our dash is an idiot light with a needle. it usually registers about dead center and it has no numbers on it. it's not a voltage gauge. if your BATT light comes on, your alternator is not charging your battery and your vehicle is running off the battery, which will eventually drain it.

A note here...the battery gage is, indeed, a real gage, which will, under normal conditions, stay somewhere within the confines of the battery graphic. How do I know? When my alternator went south, (at night!) the needle gradually moved south as the lights got dimmer and dimmer.The oil pressure gage, however, IS a glorified idiot light. Either half gage or no gage. Still trying to figure a way to turn it back into a real working oil pressure gage...

Bill

 

[koda2000]

A note here...the battery gage is, indeed, a real gage, which will, under normal conditions, stay somewhere within the confines of the battery graphic. How do I know? When my alternator went south, (at night!) the needle gradually moved south as the lights got dimmer and dimmer.The oil pressure gage, however, IS a glorified idiot light. Either half gage or no gage. Still trying to figure a way to turn it back into a real working oil pressure gage...

Bill

well, it's kinda a real voltage gauge, but a real voltage gauge has numbers on it and the needle tends to move around a bit under normal operating conditions. not just sit in the middle. the sending unit for the oil pressure gauge is an on/off switch. you either have oil pressure or you don't, so yes it's a glorified idiot light. the TEMP gauge isn't quite real either. mine would not move off COLD when i had a bad thermostat, even though the coolant temp was around 160 F.