Looking to repair our M4000 temp/humidity sensor cable, can anyone help with the pinouts? Connector pins are labeled 1-4, need to know which color goes to which pin.
Hi, I don't remember the pinouts, but if ever the unit goes bad, it's usually either the thermistor or the humidity sensor. Doble (if I remember well) sells replacements for around $1,600 and the thermistor is $1.00 and the humidity sensor is around $10. There's a part number on the humidity sensor and that's the one that usually goes bad. The thermistor does not have a part number, but I figured it out my measuring it's resistance at two temperatures and found some with matching specs.
The sensor communicates with the main unit serially, so you won't damage anything by just trying several of possible combinations.
Good luck.
Thanks for all of the responses, hopefully its just the cable and I can find some time by end of the week to get this thing fixed. Looks like the terminals on the connector are really small, its going to be a trick to solder.
In the meantime,
If you didn't already figure it out, you can bypass the temperature sensor in the DTA settings. We had a tech leave it on a transformer thru a week of thunderstorms and had to have it replaced (sitting full of water destroyed it), but we found out he left it when we went to use it and it was missing.
Luckily, I always carry a cWheap temperature/humidity gauge I bought at Home Depot to use to input manually into DTA.
So, we tried the pinouts suggested in the thread and now the sensor gives us crazy high temperature (200C) and no humidity. Either we got the pinouts wrong or the sensor is bad. I need to get my hands on another cable to be sure but next step would be replacing the sensors.