tamd75edc problems

[rick1962]

1 of the lights on the Volvo Penta Control Unit for water temp didn’t light and the test button for the unit didn’t work either model # 873 584 so I bought the new model that has the LED lights model # 22354203 instead of the old version with the plug in lights since they stop making that part. When we plugged it in everything seemed to work perfect, all 3 lights went on, I tested the alarm and it worked perfect but when I shut the system down and turned the key off all of the lights stayed on? The only way to turn it off was to shut the battery off on the starboard engine. we switched the part to the port engine and the same thing happened? Is this normal? What am I doing wrong? Please any help would be very much appreciated…

[DougR]

I don't have any experience with the newer LED equipped alarm module, but I have had some experience with the older incandescent light equipped module, and what you are describing doesn't make much sense.

Within the Volvo Penta wiring harness the alarm module gets its power directly from the key ignition switch, and turning off the key switch should remove power from the module just the same as turning off the battery switch. So the reaction should be the same regardless of where the power is cut off from.

It may be, however that something that Regal wired is backfeeding a low level of power into the module that keeps the LED lights alive, but it's not enough to light the incandescent lights. Or it may be that the circuitry within the new module has some capacitors that charge up and take awhile to discharge thru the LEDs thus keeping them lit for a time after turning off the key.

I think I might try turning on the key and powering up the system and then pull the two wire power plug on the rear of the module (red/blue and black wires) and seeing if the lights stay on. If the lights go off immediately, that indicates the module isn't charging itself up in any fashion. Then plug the power back to the module and with a volt meter on the power lead, turn the key off and see if some level of power remains on the module. A little investigation should point you in the right direction.

DougR

[rick1962]

I did what you said Doug and found that there was 12 volts on the starboard side, port was 0. I think its the key switch thats faulty. Thanks very much for your help
Rick