Originally Posted by Locchamp
I have two 6v batteries so shouldn't be that
2016 mini lite 2306
2012 Chevy traverse
Assuming batteries are healthy and well charged and the pump is not defective, the load is pulling more than the circuit can provide. So I would first suspect a poor ground. The point where the negative battery cable is screwed to the frame would be the likely culprit. If not a dirty or corroded connection there, oh and battery cables are clean and tight. Then look for loose or corroded connections and where between the batteries and the pump. Something is making that pump pull all the available current. Sadly a volt meter will not help much because voltage will only drop when the pump puts a load on.