Automotive Digital Timer Relay Board DC 12V 20A 1500W Module with Dual Display, Timing Relay Switch ON-Off Control Support Cycle of Time Delay for Car Vehicle (DC 12V)

Great timer! Works well for a hot water recirculation system in a camper. I wired a doorbell button (momentary switch) to activate the timer to circulate hot water through the plumbing. I have the timer wired to shut off and remove power from itself after running for a set number of seconds. This prevents unnecessary draw on the RV batteries when the timer is not in use.Operation: 1. Momentary switch energizes timer circuit and included board-mounted relay, starts countdown, and retains power to its own circuit after momentary switch is released. 2. The timer circuit counts down to zero, cuts power to the relay and therefore to its own circuit stopping all power draw from the timer. Cycle repeats when timer is started with the momentary switch.Timer wiring legend (see photo):12V+ ---Purple = 12vdc positive to power timer---tied to power supply +12vdc12V- ---Green = 12vdc negative to power timer---jumper to yellowS1 ---Orange = 12vdc negative to supply side of relay---tied to power supply -12vdc (chassis ground)S2 ---Yellow = 12vdc negative to load side of relay---jumper to greenMomentary Switch (doorbell button):Pole 1: Orange---(S1)Pole 2: Green and Yellow (12v- and S2) tied togetherNotes:Timer has non-volatile memory and retains settings after power loss.When activated, the relay on the timer circuit will pass thru whatever is attached on terminal S1 to terminal S2.I chose to use chassis ground (12V-) to activate the timer and water recirculation system.When timer counts down to 0, the relay is released and power to timer circuit is turned off (loss of ground).I only tested the countdown program that was needed for my recirc system.The terminal block is flimsy, but the timer was nine bucks, case included, and it works.I've attached photos of the circuit board product as of 2-26-2021 and a photo of my wires.Some assembly required. My unit came with the membrane front and the circuit board not fully snapped into the case. That's actually a good thing. They must know that my first step was to take it apart and see what's inside. :)The unit is easily assembled (snapped into place) once inspected. :)Instruction sheet was included.For a video on how the timer works, search for this: 4TTvfSYy204

Bought this in an effort of controlling a solar panel system on my RV. The batts do not need to be charged daily if they are not in use (even though the controller should take care of it). While in storage, I have the batts refreshed for a few hours only once a week and ever since I installed this, I extended the battery life. For what I needed, this was a great product with lots of programming options.

This review saved a return for me Amazon Customer3.0 out of 5 stars No DirectionsReviewed in the United States on October 20, 2022Color: DC 12VVerified PurchaseWould be a 5 star if it would have directions. It does work if you can figure out how to wire it up. You must (Y) from your positive source (+) and (S1) then (S2) goes to the positive side of equipment to be turned on. The negative (-) side must also be Y'd to go to equipment. Programming is fairly simple many youtube vids to help with programming. The connection terminal block is very cheap so caution when tightening your conductors.

When it showed up the antistatic bag it comes in was cut open and its all scratched up. Don't know if it usually comes with instructions but mine didn't have any. not too hard to figure out but some simple instructions would have saved me a little time.

Would be a 5 star if it would have directions. It does work if you can figure out how to wire it up. You must (Y) from your positive source (+) and (S1) then (S2) goes to the positive side of equipment to be turned on. The negative (-) side must also be Y'd to go to equipment. Programming is fairly simple many youtube vids to help with programming. The connection terminal block is very cheap so caution when tightening your conductors.