Tank sensor lights not working

enblethen wrote:
First thought is reversed power and ground.
Have you checked the common output to one of the tank sensor?

Yes, good thought. For sure check, if the PC board is wired correctly, the light bulbs can work with reversed polarity but the PC board can have issues.

Is this the tank monitor you bought? https://www.recpro.com/rv-kib-tank-sensor-monitor-panel-m23/

If so, that is a KIB brand monitor. You can not get the tank lights to come on if I read your note correctly. Yes/no?

Not sure what you did under the camper; the tank sensors must have a working ground wire. Rust and corrosion have corroded the ground screws and loose contact. If you have an ohm meter, test the tank ground pin wire at the tank to a known good chassis or battery neg (-) ground.

Next, there have been cases where the tank signal wires get skinned and shorted to chassis ground going from the wall down to the sensors. I have had this happen, but it only affected 1 sensor, not all of them in my case; I was lucky the other wires did not get skinned. I had to pull a new wire.

Regarding the tank red resistor packs, did you change them and have them hooked up correctly?

KIB was bought out/merged with America Technologies. I cannot seem to find the old KIB site anymore, and the American site does not show the KIB systems that I could find anyway.

I did find this KIB manual, it may help. https://www.dutchmenowners.org/forums/f59/kib-enterprises-tank-monitor-panel-tank-wiring-information-4374.html

Hope this helps.

John

First thought is reversed power and ground.
Have you checked the common output to one of the tank sensor?