When using the microwave and a electric grill, I lost all power along two walls. I put a new GFCI outlet in, but it was not the problem. I checked the power and it shows real low voltage and the little light on the GFCI is on but normal appliances won't work. I took and tested another outlet and when I touch the tester to the wires the light on the GFCI would go off and on when I touch the wires. I shut off breaker and put tester on turn breaker on and seem to have plenty off power there. Just lost now
How can you tell it's low voltage? What are your points of reference for measuring voltage: hot to ground or hot to neutral? If hot to neutral, then the low voltage difference could indicate that the hot and neutral both have high voltage on them (e.g. 119.8V between hot and ground and 119.2V between neutral and ground which would show a low voltage difference between hot and neutral of only 0.6V). If the neutral has high voltage, this would most likely indicate an open neutral (i.e. a disconnect somewhere on the neutral leg of the circuit).
If all the other outlets on the circuit are working normally, I would check the ones closest by for a loose white (neutral) wire as they most likely daisy chained to feed the outlet you are currently having issues with. If so, I would guess the issue was probably due to plugging/unplugging something on these outlets that jostled an old "stab-in-back" receptacle connection loose. That said, without seeing your homes wiring diagram, it could potentially be anywhere on the circuit so my suggestion may just be a starting point toward finding the open neutral.
This is not as hard as many make it sound. With several outlets going out with a load it is most likely a failure of 1 connection because of a daisy chained circuit. The first outlet with no power or last one with power are the 2 locations to check if the circuit breaker is good. The problem can be on the black hot wire or the white neutral. figure out the location of the first non working breaker turn the power off and pull it out from the box you are looking for back stabbed connections that are loose (wires pushed into the back of the outlet) most common cause. a broken wire is also a possibility or one that has pulled loose from a wire nut. If all the connections are solid go to the first working outlet and do the same check. I have suggested this to folks that pulled the outlets and now everything works because the wire in the back stab made a connection (this outlet needs to be replaced) I only use back and side outlets that have a clamp and think back stabs should be outlawed this is the #1 electrical failure I have found over many years. A wire that was nicked at install can break at the nick but that is rare compared to the failure of back stabs. Give it a try you can save your self enough to go out to a nice dinner and now you know how to do it if other outlets fail in the future.