Hi my name is dart my wife has a 2006 Saturn vue with the 3.5 Honda motor and we just put a battery and alternator in it and it started this morning and now it acts like the battery is dead so gave it a boost but five seconds after removing the cables every thing in the car shuts off and losses all power power steering radio dash lights interior lights exterior lights, the gas Guage and temp Guage still work rpm drops to zero but the car is still running

 

I suspect that one of the small power wires is not connected properly. Review all your connections.

 

I've checked everything twice

 

What made you replace both the alternator and battery? Is this the same problem as before? Is the new alternator charging correctly?

 

I had my dad check it with a multi meter and he said the alternator was gone and the exact same problem as before and it seems like it's charging

 

You may have some sort of a body control module problem. I do not have a VUE and I do not have a factory service manual for a VUE. I would want to see 14.2 volts at the battery, idle with some electrical load. I am not sure how GM integrated Honda powertrain and GM body controls. I also think the Honda powertrain is better than the 3.0 54 degree GM v-6 that was in the earlier VUE.

 

How can the alternator be charging the battery and gone at the same time?

Fusible link checked betw alt and battery?

This is in line usually in the pos batt cable run between the alternator and the battery. If it burns out, that part of the circuit is open. So depending on how it's wired, you may still have battery current going to the starter, so the car starts. However you do not have the alternator charging the battery and feeding operating current to the rest of the car, so you are running the rest of the car off the battery once it starts instead of off current that is generated by the alternator. Your battery has probably not been charged for quite a while now so it cannot supply all the current requested of it.
I would check to make sure the fusible link is intact. You should be able to do a continuity test between the alternator output and the positive terminal of the battery. If it is not continuous, it is likely the fusible link.