Originally Posted by bobothewizard
So looking at the schematic it doesnt seem as complicated as i thought. It really is only a positive and negative wire broken by a switch on the negative
Bobothewizard, not sure here what schematic you are looking at or I guess switch. If you are talking about the switch to the electric heating element on the Suburban, this switch has no negative wire. The blk wire is 120 volt hot, as this is 120 volt AC house wiring......not 12 volt DC automotive. Please do not confuse them.
The switch just breaks power/continuity on the 120 volt hot leg/line....then the same line goes to/thru the ECO hi-limit/thermostat...then the same line to the electric heating element.
Because you do not have a neutral or ground wire connected to either the switch or the Emergency Cut Off Reset/thermostat...then when you are using you multimeter to test, you have to place the multimeters negative probe on a ground somewhere to test for voltage. You will not be able to place one probe on one terminal of the switch and the other probe on the other terminal...since you are testing voltage and have to have either a ground or neutral to do such.
Same applies to testing the ECO/thermostat too.
Hold on and I will get you another thread I explained this in to help.