Low voltage and no crank no start with full battery

[Tripp595]

My sport trac is showing low system voltage with a fully charged battery sitting at 12.6 volts, I have checked all relays, fuses and wires at the fuse boxes. I have replaced the battery and alternator but it still shows low voltage. Any ideas?

 

[Fix4Dirt]

My sport trac is showing low system voltage with a fully charged battery sitting at 12.6 volts, I have checked all relays, fuses and wires at the fuse boxes. I have replaced the battery and alternator but it still shows low voltage. Any ideas?

voltage tegulator?

 

[Josh P]

How did you check the relays and fuses? Did you use a volt meter?

 

[Tripp595]

How did you check the relays and fuses? Did you use a volt meter?

I used my fluke 87 multimeter

 

[Tripp595]

voltage tegulator?

I have a new voltage regulator unless there is another one not connected to the alternator?

 

[Josh P]

You have 12.6 at the battery, what is the voltage in the fuse panel?

 

[Tripp595]

You have 12.6 at the battery, what is the voltage in the fuse panel?

12.56v

 

[BrooklynBay]

Did you check the high current fuse on the alternator's wiring? Is there an alarm system disabling the starter or the ignition system?

 

[Tripp595]

Did you check the high current fuse on the alternator's wiring? Is there an alarm system disabling the starter or the ignition system?

My pats system is active, but I read that the low system voltage could cause the pats to disable the vehicle

 

[BrooklynBay]

Do you have another PATS key?

 

[Tripp595]

Do you have another PATS key?

I had two new keys programmed and same issue

 

[Josh P]

Looking at a wiring diagram, looks like at the alternator, the red and green wire is what turns the regulator on, goes to the instrument cluster. Are you sure the ground wires are ok?

 

[Tripp595]

Looking at a wiring diagram, looks like at the alternator, the red and green wire is what turns the regulator on, goes to the instrument cluster. Are you sure the ground wires are ok?

The grounds are reading 0.4 ohms and the wires are reading 12.32v