My rc939 wont work unless right next to receiver.

https://www.manualslib.com/manual/979036/Intermatic-Rc939.html#manual

Sometimes, you have to remove all the batteries in the transmitter and receiver and wait a few minutes before the next step.

Then you replace transmitter batteries first and within 30 seconds, get the batteries installed in the receiver. This allows the receiver to link up with your transmitter. Both units need to be reset this way. You'll see the temperature and any other information the transmitter provides come up in a few minutes. This works with my La Crosse weather station. Using the reset buttons without removing power will not work. My nieghbour has a weather station from another manufacturer and this is also the only way that his will link up.

Have transmitter reprogrammed by dealer if you cannot,
press the helpful button and check link below

2003 to 2005 Honda Pilot Factory Remote Transmitter Programming

If you want to check if your remote is working and you have a cell phone that takes pictures hold the remote in front of the camera and when you have a pitre of the remote press the button and you see it on the camera if you don't the remote is not working hope this helps (this goes for all remotes ) Tom

Sometimes if you press both remote buttons on a transmitter at the same time next to the vehicle for more than 10 seconds it will reprogramme a remote

Might have to take it to the dealership and have it reprogrammed if it's the stock transmitter & receiver since it did not work before or after battery change. If it's aftermarket then anyone who installs may be able to reprogram it for you. May have to take it in and have the receiver checked to see if it's connected or still operational.

1) Review both manuals for advisories that might apply to your installation.
http://waterheatertimer.org/pdf/RC613-RC613L-RC615.pdf
http://waterheatertimer.org/pdf/Intermatic-remote-RC939-manual.pdf
Reset receiver and then 'reprogram' to transmitter
Contact Intermatic 815-675-7000
Each transmitter and receiver have 1 year limited warranty.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

does the 2nd transmitter work

if no, then your receive may have failed

if you don't have a 2nd transmitter, then you need to take your vehicle in for service and either have the failed parts replaced or best case, have the transmitter or receive reprogrammed

On some mics, one of the lights will NOT turn on unless the battery is low. The mic is the transmitter, so I am not sure what you mean by it not lighting, but the transmitter is lighting?

Make sure the mic's freq. is within the scanned range of the receivers. Often the mics get mixed with other receivers and the resulting pair are incompatible.

The receiver should show if signal is being received. If it is, then the module in the microphone dynamic cartridge MIGHT have been damaged. If it is damaged, it has to be replaced.

REPRIORITIZING A TRANSMITTER’S PROGRAMMING:
To reprogram a receiver channel with a different transmitter button once a code has been stored, there will be two options:

1. Enter the transmitter program mode of the receiver channel to be reprogrammed. Using any unused button or combination of buttons, push out the stored code by pressing the unused button until a long chirp is heard, then repeat 3 additional times. After this, you can add any desired unused transmitter button. This action erases only that particular receiver channel, all other codes will remain stored.
2. Enter the transmitter program mode. Using any transmitter button press and hold until a long chirp is heard. If a single chirp or multiple chirps, (up to 7 chirps), are heard, the unit is indicating that the transmitter has already been programmed elsewhere in the receiver. Release the transmitter button and within 5 seconds press and hold until a long chirp is heard. This action forces the unit to erase all stored codes of that transmitter.

The unit then exits the program mode the siren emits the program mode exit chirp pattern. All transmitter buttons for that transmitter must now be reprogrammed. Any other transmitter stored in the unit’s memory still remain operational. If the button is released and not pressed again within the 5 second period, no change in programming has been made to the receiver channel. The programmer can move onto a different channel or erase the transmitter codes as described in 1 above.
Regards, Martin @ http://www.lesscoelectronics.com