Excellent 90380 Relay Wiring Diagram HVAC More About SPST, SPDT And SPNO-SPNC Relays - YouTube - Whilst there may be a warmth call the board sends the low voltage name to those sequencers which have high voltage attached on it's terminals which are the m numbers. When he low voltage is despatched to those they near the bridge across them so the high voltage is then transfered to the other aspect of the sequencer which the electric strips hook to. Yes, if the furnace endured to run with all of the thermostat wires unhooked to the furnace then yes it is the one or both of the sequencers. If it turned into the blower relay that is the square box searching one then simply the fan could run all of the time without the strips being on, but in view that each are on meaning it must be a sequencer.
The wire hooked under w2(aux on some stats) the wire hooked under e, and the g terminal on the thermostat need to be taken off where they hook in to the furnace. If the furnace continues to run the electrical strips and the fan with these 3 wires off then there's an internal trouble with the furnace. If the furnace does no longer run then there may be something crossed or wrong with the thermostat/wires. In case your problem is that both the heat strips and the fan retain to run then there may be a manner to isolate climate it's miles a heat sequencer or fan relay or if it's far the thermostat or the wires going to the thermostat.
I discuss extra about spst, spdt and spno-spnc relays. Attention: do no longer try any of what you see on this video at domestic. It takes at least years of hvacr training to grow to be qualified to learn inside the subject how to paintings on heating and air con device. Then it takes any other three years of apprenticeship training to become able enough to safely work on heating and air conditioning gadget. To donate cryptic currency: peercoin: pfcmau4dx2qm4ymwog3wfkkmkp7oxjhejd.