the 2 white grounds and 1 green ground are all solid, zero resistance in any of them.

Zeke's idea is the best solution, depending.

you ran a single ground wire, 2 neutrals and two hot wires.

if the loads on the two circuits are roughly equal, you can share the neutral between two hot if they are on separate phases.

if they are on the same phase or the loads are grossly unbalanced, you need to keep the second neutral.

i can walk you through it if that is the way you want to go.

That will probably be the short term solution, both hots are on the same side of the bus and all the grounds are too.

I understand why the hots need to be the same phase(on the same side of the entrance bus) but why is the load significant?

1 circuit is mostly lights and unused convenience AC outlets w/ occasional air compressor, garage door and hyd lift loads the other is lights, a couple of convenience AC outlets and a 1hp pool pump that isn't currently being used but will be in constant use in another couple of months

to get basic, what you would be doing is turning the circuits into a multi-wire branch circuit. with the two hots on different phases, the harmonics zero out the load on the neutral. it is actually more complicated than that, but this is a car forum.
i'm trying to figure out a situation where sharing the neutral wouldn't work.

could a small animal have gotten in there and effed things up??

If you have 230 volts you only need one neutral. If you have two 115 volt circuits you need two neutrals.

You must have a ground fault. Did you check the live wire to neutral and live wire to ground resistance?

And check the line voltage to a known ground.

I checked all 5 wires separately, the only line w/ any resistance is the 1 hot black, the hot yellow , 2 whites and 1 green all have zero resistance

the 2 circuits are 20amp 120VAC each, no 230 involved.

I doubt it, everything is buried 2' down the above ground conduit is on the side of the house and side of the garage, both are intact and undamaged. I suppose somewhere out in the buried part an animal could theoretically have gotten to the conduit but chances of that are astonishingly small. The only burrowing critters around here are Chipmonks which are persona non grata around here and sent packing w/ dispatch, they love to burrow under the pool patio area.

you have a variety of mice & shrews as well

my thought was they got in at one end or the other...

sorry you have to pull it all out - but hope that is all you have to do...

I had a friend [who knows A LOT more about electrical wiring than me] and one day recently he was testing for voltage on an outdoor fixture while I was looking over his shoulder and the voltage didn't register correctly. I went to my truck and got my voltage tester and it tested fine. Turned out his tester was faulty. :rolleyes:

Carambola's suggestion makes sense. The vom (volt/ohm) meter you are using is probably digital. An Analog meter isn't as sensitive and actually shows you a more accurate working voltage. Conduits fill with water in most applications. That is why the wire insulation is rated for this. THHN and THWN provide insulation for wires that are in conduits that normally fill up with water.
You have a circuit that has high resistance and if it isn't at the terminals at either end... Pull a new conductor.

Bill's tester is not faulty. He sees 115v where it is supposed to be and he sees 50v where he should see 115v. And the resistance he sees is exactly why. It's Ohms Law.

That black wire is now useless. 4 wires is enough to have 2 operating circuits to the garage. Sure, if you took the yellow and the "new" hot and measured across them, you would see 230v as long as they are on different legs. The fact that they are on one side of the breaker box suggests they are. And they certainly are if they are next to each other.

Only one neutral needed for those and a ground for safety. It is a misnomer to call a neutral a ground. A ground is an equipment ground and safely grounds the whole system. The neutral completes the circuit by connecting the loop back to the box. The fact that they terminate at the same point does not mean they come from the same point when something is energized by that circuit.

Bet you got a mouse in the conduit and that is the cause of all this.

Like Zeke said, you can share the neutral wire for both circuits so you could tape off one of the neutral's and make it a hot. As long as it's taped/marked with black it will comply with code as well.

A couple of weeks ago I was testing some electrical wiring and I was getting all sorts of results. The digital circut tester was working but the results were a bit whacky so I changed out the battery for a new one and things came right.

Believe me it's not the instruments, the thing that attracted my attention to it was the fact that the area lights weren't working.

ok, here is what you do. you got a shopvac? get a wawa bag and attach some kite string to it. used the ne string to pull a new conductor and take some pictures of it. please post them and tell us how it goes.

^^
Wawa bag?

Found the issue

The conduit goes under the driveway, the first conclusion was that the trench had settled, taking the conduit w/ it, breaking the conduit and 1 wire, after digging it up the conduit was found to be intact.

After pulling the wires and inspecting them I found that the defective wire had been arcing to the conduit eventually burning itself out.

I'll run all new wire and keep my fingers crossed.

What a PIA:(

Did the wire burn its insulation off or burn copper?

I'm going to remember this thread and reverse the offending hot and ground next time I encounter this problem. Nothing better for a ground wire than one that is grounded. At least it won't arc.