Kitchen Large Electric Appliances - Roper Dryer model RES7745PQ0 - No spin, No heat.

This is info from three posts I made in another area of this forum. A member suggested I post here. I hope you all can help me. I have been diagnosing for almost a week and not finding the gremlin!

Thanks in advance! Greg

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I have a Roper Dryer model RES7745PQ0. It is about 3 years old. It has been working fine until about 2 weeks ago. Two weeks ago, the dryer stopped heating. So I pulled the heating coil. It had a break and I replaced it with a new one.

The dryer worked fine at that point and ran and dried perfectly for 5-10 loads. Two nights ago, the dryer stopped working completely. The timer motor runs and advances when set on the manual timer. But the tumbler motor will not start and the heating element does not heat.

Here is what I have tested so far:

I have ~240v at the wall and at the cord connections to the dryer.
I have ~115v at the L1 to ground and L2 to ground.
The door switch has continuity when closed and open when open.
The "push2start" button has continuity (w/ slight resistance) when pushed.
The "thermal cutoff" has continuity.
The "thermal fuse" has continuity.
The "heater coil" has continuity.
The "thermostat heater" has continuity (w/ slight resistance).
The "operating thermostat" has continuity.
The "hi-limit thermostat" has continuity.
Timer motor advances in manual time mode.

Are there any tests I can do on the motor and/or timer to determine where the problem is? The timer is $80 and the motor is $95. If I have to replace both to find the problem --or not-- (plus the $50 I just spent on the heating coil) I might as well buy a new one...

I have the schematics Model RES7745PQ0.

Any help would be greatly appreciated! (By me, my wife and maybe the kids too!)

Thanks in advance! Greg


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I have the electrical schematic found here: http://www.servicematters.com/docs/wiring/Wiring%20Sheet%20-%208528190.pdf

I have traced my way through it. There does not seem to be a tension switch on the belt pulley on this model. The tensioner is a pretty simple spring bar with a pulley.

I have checked both thermostats and the thermal fuse. They both test good. I by-passed them too and it still did not start.

Any other timer or motor tests possible? It seems from the schematic on the link above, there are about 5 switches internal to the timer and at least one in the tumbler motor.

I read on another forum that one can "120v hot-wire" two of the connectors on the tumbler motor to make it run without the timer, etc. Can someone show me which connectors to use to try this?

Can someone explain the top part of the electrical schematic linked above? The part labeled "Timer Switch"? I really need to figure this out without spending $200 to do so.

Thanks for any help you can give. Greg

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Buzz (and anyone else that wants to jump in please do so!),

Thanks for the input on the Timer Switch legend. That helped, I think. All that made sense I checked. I checked out the TM-OR, TM-WB, BK-BU, and BK-R connections. They all seem to test as indicated in the legend.

I cannot figure out the last two columns: the two columns labeled T-W. When I test the Tan-white wires at the switch they test "all open". But I cannot figure out what the condition is in the last column to test it out T-W. (Looking at the Timer Switch diagram there are two columns labeled T-W).

Also, exactly what connections am I supposed to make for the BK-BU-V test? If that is supposed to be BK-V then the pattern there is not what I get at all. Does BK-BU-V really mean BK-V???? If not, what does it mean?

I took the bottom end of the dryer apart so I could get to the motor. There are a lot of wires going into the motor. But once I removed the wire socket from the motor I could test the wires on the motor. There were two red wires going into the motor. There is no connectivity between them on the motor. The ends that looked to be the coil wire ends have connectivity. I did not see the 2.4-3.8ohm resistance listed on the diagram, more like 0.7ohm.

There is a diagram of the "pluggable drive motor switch" (leads going into the motor) at the bottom of the electrical schematic. http://www.servicematters.com/docs/w...%208528190.pdf On the motor, the two reds have no connectivity. The coil wires directly have 0.7ohms. So do the white-blue and the white-violet. (But I should note that there is no violet wire leading to the motor on this unit. That measurement is across the prong that is designated as violet on the diagram.)

I hope you all can give me some more advice. Just called the Sears repair place and they want $120 to look at it. The only other place in town wants $70 for the visit but their parts are 150% higher than parts from Sears.

Helpppppp! Thanks. Greg

Looks like you have done all the tests There is a centrifugal switch in the motor, Am trying to remember how to check.Not something that goes out to often. Did the motor hum when you pushed the start button?

Looks like you have done all the tests There is a centrifugal switch in the motor, Am trying to remember how to check.Not something that goes out to often. Did the motor hum when you pushed the start button?

I did not hear any hum from the tumbler motor. There is a bit of a hum from the timer motor. The tumbler motor spins freely by hand. I tried it without the tumbler on (and with the door switch wires jumpered) and got nothing. I did not think to check for VAC down there when it was on... :wall:

I have already put it all back together, but I am getting pretty good at breaking it down.

I read somewhere that the centrifugal switch in the motor is just for switching on the heater (safety feature to shut off heat if motor stops). Is that right?

QUESTION: Which wires would I "hot wire" with 120v to make certain the motor turns? That seems to be the last test.

QUESTION: I am still a little confused by the legend on the schematic about the BK-BU-V readings? Got any suggestions on which posts to connect on that test?

QUESTION: Also, the two columns of T-W tests on the schematic legend do not make sense either? Can someone explain those?

The electrical schematic is here: http://www.servicematters.com/docs/wiring/Wiring%20Sheet%20-%208528190.pdf

The wife is ready to buy a new one, but this one is only 3.5 years old... They should last 10-20 years.

All suggestions appreciated. Greg

I cannot figure out the last two columns: the two columns labeled T-W. When I test the Tan-white wires at the switch they test "all open".


you need to continuity from T to W for the motor to work. you have a bad timer

you could carefully touch a jumper wire across them and see if the motor comes on.

you need to continuity from T to W for the motor to work. you have a bad timer

you could carefully touch a jumper wire across them and see if the motor comes on.

I tested both T-W connections and both were open in all settings (no connectivity). So I put a jumper temporarily between the T-W, pushed the "start" button and the tumbler motor started (after a nice spark).

QUESTION: So it pretty much has to be the timer, right?

I meant to do the test for 120vac at the motor when I had the box opened. I'm thinking I do not need to do that test since the tumbler motor turned when I did the T-W jumper at the timer.

The cheapest I can find the timer for is $65 +SH. But that is a lot better than $120 for a house call and $112 for the part!

You guys are awesome! Once I hear back that I am making the correct call on the timer, I'll order it...

Is there some cheap parts place I am not finding with 'Google'? I cannot find the exact timer listed on eBay.

Thanks. Greg

I tested both T-W connections and both were open in all settings (no connectivity). So I put a jumper temporarily between the T-W, pushed the "start" button and the tumbler motor started (after a nice spark).

QUESTION: So it pretty much has to be the timer, right?

I meant to do the test for 120vac at the motor when I had the box opened. I'm thinking I do not need to do that test since the tumbler motor turned when I did the T-W jumper at the timer.

The cheapest I can find the timer for is $65 +SH. But that is a lot better than $120 for a house call and $112 for the part!

You guys are awesome! Once I hear back that I am making the correct call on the timer, I'll order it...

Is there some cheap parts place I am not finding with 'Google'? I cannot find the exact timer listed on eBay.

Thanks. Greg
Just wanted to thank you all. You are guys are awesome! It was the timer! When I got the new one, I checked the W-T continuity in different setting positions and sure enough, it was there in the correct settings.

Thanks for helping me diagnose the problem AND save a LOT OF MONEY! My wife is very happy to be able to do laundry and the kids like the soft clothes too!

Thanks!