My problems have got problems

I'm trying to get a MendelMax 1.5 running. It has the Arduino Mega board with a Ramps 1.4 and Poulous on top of that with Marlin firmware. I'm trying to run it with Repetier 0.56 running under OS X 10.9.4. The thermistors either read 0° with the heaters off or full temperature with the heaters on, even though they check out in the 80-90K ohm range on the DMM. Nothing wants to move because of endless "Error: stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting.)" With no saying what any of those those endless errors are. And when something does move, the Y and Z motors run backwards. And then they don't stop, despite that the estops all check out on the DMM. Please, help. Thanks!

The first G-code that you will be learning is M119. It shows what the firmware thinks your endstop switches are seeing. Get them sorted out first, as they cause weird motor behaviors like steppers not moving or only moving in one direction.

With the thermistor problem, is one of the leads shorting out against the heater block?????

I just run the M119 J-code. So far x-min, x-max, and y-min are triggered without anything touching the micro-switch levers. Y-max, z-min, and z-max are open. So what now?

I just moved some of the pigtails over and now I got x-min, y-min, and z-min triggered with nothing touching the micro-switch levers. X-max, y-max, and z-max are now open. What's next?

Remember that the switches are considered triggered when they are in the open state. The switches themselves should be wired on the common and NC connectors, so they go 'open' when the lever is hit. The ramps board has provision for axis min and max switches, so you must have jumpers on the unused end stop pins, which tricks the board to thinking it has switches attached.

Test each switch with an M119 command until they all read triggered only when triggered. If there is a problem, you can either change the wiring or else invert the endstop signal in firmware. With the endstops working correctly, your stepper motors should then move in both directions in Repetier Host.....

Thanks so far! I swapped wires on the micro-switches and got them working right. I repinned a couple of motors and got them turning the right direction. I changed a couple of firmware settings and got the thermistors to read right.

Know my current problems are that the X and Y axises only move about 9mm when I jog them 10mm. And the Z axis only moves about 1mm when I jog it 10mm. What do I need to configure now?

follow this calibration guide [reprap.org]

Okay, does having the Ramps board jumpered to do 1/16 steps affect anything? And how do you level both screw-drives of the Z-axis?