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bimbbobway

Defrst timer blues, I confused my self

17 posts in this topic

I am working on a Roper. RT14BKXKQ03 VSP3541151 refrigerator and need to replace the defrost timer. It is kicking my butt! I installed the new defrost timer very common part number 482493. I install these all the time and normally when I put the jumper on the proper terminal I can see the motor spinning all the time both in compressor run and in defrost. However when this compressor is on the timer does not advance. when the compressor is off or the thermostat shuts the compressor off. the timer will advance. This seems backwards to me. I have put the jumper wire on all four terminals and tried it. It works the same way on terminal one and terminal three. I'm a little confused I don't know what to do. I have installed many of these timers and now I am second-guessing everything I remember about these timers LOL. I attach the wiring diagrams please help

Edited by bimbbobway

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Need appliance parts? Call 877-803-7957 now!

Wiring Diagrams

post-2752-0-99460300-1366891716_thumb.jp

post-2752-0-12301400-1366891753_thumb.jp

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different Fridge wiring diagrams use different connections to the Defrost Timer

Your Fridge wiring diagrams show it to be a:

 

“Version 1”
Cumulative compressor run application
Installation instructions for replacing 8-hour or 10-hour cumulative compressor run timer.
If wiring schematic looks like this, you have a Version 1 cumulative compressor run timer application.
See Figure 2.

 

NOTE: The wiring harness coming into the timer has a red wire; this will be a cumulative run hookup.
See Procedure 2.

 

Connect loose wire to terminal #2.

(Defrost Timer will only run when Compressor runs)

IF Defrost Heater & Bi-metal are good (and cold / closed)

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yes so you would think. that's what I thought. But when connected it will only advance when the compressor is off.

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... it will only advance when the compressor is off.

it will, if it's actually in the Defrost cycle

(during that time, the Compressor can't be started by turning Cold Control colder)

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With the timer in the " compressor run position","the cold control closed",and compressor is running the timer will not advance. I you turn the cold control till it opens the circuit the compressor shuts off and the timer will advance.

in defrost the heater comes on and the timer advances like normal.

With the timer in the " compressor run position","the cold control closed",and compressor is running the timer will not advance. I you turn the cold control till it opens the circuit the compressor shuts off and the timer will advance.

in defrost the heater comes on and the timer advances like normal.

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then something is not wired correctly...

 

Timer

|  |  |    |

2 1  4    3

P B O   R

 

should be:

2 – Pink Wire

1 – Black Wire

4 – Orange Wire

 

3 – Red Wire

 

and Connect loose wire to terminal #2.

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Yes I know it has to be a wiring issue.  The timer is wired up correct.  What other then then the wiring to the timer could cause this?  I have checked the compressor and it is correct.  Everything in the defrost looked correct.  I kinda lost. 

Edited by bimbbobway

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.... The timer is wired up correct. . 

check it again...

can you post a picture ?

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I'm going back out on Monday,  ill take a pick then. 

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OK, are you sitting down??  Here we go.....

 

 

Reversed polarity... and a shorted to ground Pink wire on the Defrost bi-metal......

 

In Cool, the Tstat closes but is now sending neutral up to the red, combined with the short to ground we have no opposite potential so the timer does not run when the tstat is closed in cool. SInce the short is on the neutral side due to the reversed polarity, we do not pop breakers. When the tstat opens, L1 goes through our loads due to the reversed polarity, up the red wire to one side of the timer motor. Thus timer motor runs in cool with the tstat open! The shorted Pink wire to chasis ground acts as an opposite potential which turns on the timer motor...... In defrost it would work fine because with the reversed polarity we would be sending out neutral on the pink wire which would not pop anything.... sorry had to catch my breath......... the only flaw to this theory is.............................................................................................................................................................................................................................................

 

in refrigerate your heater would be staying on....the heater isn't staying on is it??........... Sorry Bimbbob! I was trying brother!!

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then something is not wired correctly...

 

Timer

|   |   |      |

2   1   4       3

P  B  O       R

2  

 

should be:

2 – Pink Wire

1 – Black Wire

4 – Orange Wire

 

3 – Red Wire

and Connect loose wire to terminal #2.

As mentioned, the "black loose Timer wire" should connect to # 2 Pink

I think you have it connected to # 1 Black   :whistling:

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You have to admit my version, though one in a gabillion (it is a real number I think) was way more COOL!!!!!!!     

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yes !

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uh oh \there goes that whistling again.  Usually means an obvious error or remedy. I couldn't even begin to repeat or follow Trying's scenario. On a good day I think I can follow "move the black wire to pin #2."

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I'm pretty sure that on these cumulative run versions the defrost timer won't start advancing in compressor run mode until the defrost bi-metal is satisfied/closed.

 

The defrost timer motor neutral is completed thru the defrost heater and bi-metal.

 

Jump the defrost bi-metal test plug to prove it works when defrost t-stat closes, the test plug looks like it will be right near the defrost bi-metal from the wiring diagram, (pink and brown), sometimes this test plug is located in the control box area.

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... IF Defrost Heater & Bi-metal are good (and cold / closed)

... in defrost, the heater comes on and the timer advances like normal.

 

... the defrost timer won't start advancing in compressor run mode until the defrost bi-metal is satisfied/closed.

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