door locks cycle & lights turn off

[Jabbo626]

When I drive down the road, the door locks will attempt to lock, the battery meter will drop from about 15 volts to about 13 volts, the dash lights will cut off & back on, then the battery meter will begin to rise back to 15 volts. It will do this about every 3-4 minutes. At night, all the above will happen, but my headlights & dash lights will turn off for about 3 seconds, & this will happen every 3-4 minutes. If I lock the doors & wait about an hour, the key fob has trouble unlocking the doors. When it finally unlocks the doors, I turn the key to ON & all the lights on the dash come on, but the truck will not attempt to start until the locks cycle. If the fob will not unlock the doors, I have to unlock them manually & the alarm starts to chirp. I am not having any mechanical problems that I am aware of, just electrical.

 

I replaced the battery yesterday. I have checked the alternator while running. It shows about 14.8 volts & when I disconnect the battery, the alternator shows about 14.6. I have inspected the mega fuse & there are no signs of an arc. I have inspected the positive & negative leads off of the battery & the connectors, crimps, & the grounds look fine. They show about 15 volts running through them.

 

I appreciate any help. If this has already been covered, please send me a link.

 

Thanks

[sefiroxx]

Sounds like the voltage regulator in the alternator is going. May be subject to mechanical vibration.

 

Sent from my XT1053 using Tapatalk

[Jabbo626]

Thanks. I'll try replacing the alternator & see if that fixes everything.

[Coby7]

Is it an 07 classic or new style?

[Jabbo626]

New style

[Coby7]

Well you can count out your FOB hanging on your key. Has to be your alternator kicking in and out.

[Jabbo626]

New alternator is installed. Problems are still there

[rjgti]

start looking for gnd issues and battery cables

[Jabbo626]

I just replaced the negative battery cable& cleaned the ground connections. I'm still having the same problems. I guess I'll try replacing the positive cable & may try replacing the ground strap that goes from the back of the motor to the body.

Any other recommendations?

[anumber1]

That ground strap between the engine and firewall is critical.

 

Make sure it is clean and tight.

[Jabbo626]

I found some cable laying around & hooked it to where the ground strap is hooked on the body & attached the other end close to a spot I found by the alternator. I drove around for about 15 minutes with no problems (knock on wood). I'm going to try & find a cable with the proper connectors on it this weekend, instead of just wrapping copper around studs.

Any idea what size wire I need?

[rjgti]

#2 cable and pick or have a battery shop crimp some ends on it for ya

[Jabbo626]

Put a new ground cable on between the engine & firewall. Locks are still cycling every 3-4 minutes. I'm starting to get frustrated