110.66822694 Kenmore 90 series electric dryer not starting

[SHELTAR]

Dryer returned to shop because a "not starting" complaint. When we tested it at the shop, it wasn't running but there is voltage at the motor. Replaced the motor but still not starting. Took one of the purple wires off of the operating thermostat and touched it to the chassis ground and the motor started right up and the dryer ran until I took the wire off chassis ground. It arced and now we can't replicate it running from chassis ground. What is going on with this dryer? Any help is greatly appreciated.

It's a old school dryer with lint trap on top.

[manden]

Do you have the wiring diagram?

Could have been a problem with the push to start switch or the door switch.

[SHELTAR]

Here is the wiring diagram. All the switches-door switch, push to start-have continuity. Thermal fuse has continuity as well. Voltage is present at the motor every time we turn it on but it doesn't want to run. It doesn't make a noise or anything.

[mz3own]

jump the temp select switch out and see if it starts

[manden]

Unplug the unit and set the timer to where it will not start.
Set your meter to it's most sensitive meter scale.
Short the meter leads together so that you can see if there is a zero offset in the meter.
Attach one meter lead to L1 on the line cord and leave it there.
Now work your way back through the motor circuit.

L1 at the terminal strip should be 0 ohms.
BK at the timer should be 0 ohms
V and BU should be 0 ohms.
Both side s of the thermal fuse should be 0 ohms.
4M (bU) at the motor should be 0 ohms.
5M at the motor should be about 1.5 ohms.
With the push to start pushed both sides of the switch should be about 1.5 ohms. Leave it activated.
Also NO to COM on the door switch should be about 1.5 ohms with the switch activated. Leave it activated
And Neutral at the terminal strip and the line cord should be about 1.5 ohms.
There that is the entire motor circuit so if you do not find the problem then I am stumped.

Was this unit ever changed fro 3 wire to 4 wire or visa versa.
Could be a problem with the ground strap or something like that.

[SHELTAR]

Manden- thank you so much for the information. We are going to try this and I'll let you know what happens.

[dab147315]

Did you find out what was going on?

[SHELTAR]

Not yet. It's in the back room of the shop. Haven't had the time to tear it apart to do the tests that have been suggested