Bosch SMU 2042 UC Dishwasher

[Tim M]

Fixed this dishwasher a few weeks ago.  There was no light next to the on/off button, no power.  Some guy had already been by and replaced the door latch switch, which was actually bad, but couldn't get it going.

I tested and found no power getting up to the on/off switch, replaced the hot wire from connection box up to the switch and it ran for a couple of weeks.  Got a call and it is doing the same thing.  Thought I'd be out of here in 2 minutes.

This time there is power up to the switch and when I click it it flow out through all 3 connections, but no light and no action in the washer.

Hmmmm.... I await your brillant reply.

Your humble servant,

Tim

 

[Tim M]

Hmmmm....  I'm looking now into the neural wire not returning the current.  If there are other things I should check let me know.

 

Now should I be ordering and replacing that whole wiring harness?

 

Tim

[RegUS_PatOff]

The ON / OFF Switch breaks the L1 and the Neutral

I have a 82 page Bosch wiring digram, and a 282 page service manual, that covers that model and others.

I could send to you if I had yopur email address.

[Tim M]

Thanks for the manual.  I just sent you my e-mail address.

It looks like the wiring harness has blown through on the neutral wire right where it gets bent by the door again.  So now I'll replace the white wire!  Then I found it for $91 bucks if that goes.

 

Tim

[Samurai Appliance Repair Man]

[user=28611]Tim M[/user] wrote:

Now should I be ordering and replacing that whole wiring harness?

You'd only need to do this if the dishwasher caught fire. :burning:

Verify that you have a valid power supply at the junction box by hooking up a lamp or some other electrical appliance to the power wires. It's important to test it under load like this because if you have a floating neutral, you'll still read voltage but you won't have current. Some background info in this War Story.

[RegUS_PatOff]

[user=28611]Tim M[/user] wrote:

Thanks for the manual.  I just sent you my e-mail address.

manuals sent

[Tim M]

[user=1]Samurai Appliance Repair Man[/user] wrote:

[user=28611]Tim M[/user] wrote:

Now should I be ordering and replacing that whole wiring harness?

You'd only need to do this if the dishwasher caught fire. :burning:

Verify that you have a valid power supply at the junction box by hooking up a lamp or some other electrical appliance to the power wires. It's important to test it under load like this because if you have a floating neutral, you'll still read voltage but you won't have current. Some background info in this War Story.

I'd already hooked a lamp up to the junction box at the bottom of the dishwasher. That went OK. Then I saw, yes it getting up to the ON/OFF switch since I'd replaced the broken black wire OF the wiring harness last time. So what I'd done this time that made me ask about replacing the entire wiring harness was this: I disconnected the nuetral in the juction box of the dishwasher and measured to see if currrent was coming back through the white wire in the harness. It wasn't.

Then I had the brilliant idea of "hey! why don't I look right where the problem was the last time?!" Profound insight wasn't it? There right where the harness bends around the door, was a second little black burn hole right next to the other one where the black wire had blown through two weeks ago. Now the white wire had blown through at exactly the same spot.

I snaked a new white wire through the harness, didn't charge him nuthin' and it started hummin' away.

So I'm wondering, given that it has happened twice at the same point, do I just leave it with my fix of 2 wires replaced, or do I charge him $91 for a new harness and put it in on my own time so he doesn't get stuck? Just as I write this I wonder if someone isn't jumping up and down on the door hinge? The springs seem to be working fine, so I don't THINK, but I don't know, that the door is jumping like crazy and whacking those wires; I really don't think so though.

I'm leaning toward let it ride, and just be ready to be out there in a flash, part in hand, if anything starts happening with this dishwasher again.

Got this Cable Tracker for $14 bucks on sale at Harbor Frieght

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94181

http://www.harborfreightusa.com/usa/itemdisplay/displayItemList.do?search.keyword=cable+tracker&submit=find+it

I didn't need it on this fix, but if I'd needed to trace any more wiring it would have been handy to do it with the circuit breaker off. GB or Sperry makes the original of this, and it sells for 10 times as much.

[Samurai Appliance Repair Man]

Nice sleuthin' there, my young apprentice.

Sounds like a problem with the way the harness was mounted rather than the harness itself. Is there any foam tape or plastic barrier between the harness and the door panel? If not, it'll just happen again, even with a new harness.

[Tim M]

There was nothing there and it does break right where it comes across a metal bar.

Now do I have to order something special or can I just use foam adhesive weather stripping? I don't think anything was there before.

It has the (older?) harness like this.

http://www.repairclinic.com/SSPartDetail.aspx?s=t-296373-%3d%3di473256&PartID=473256

Which makes a curve through a narrow metal space. Perhaps it didn't always go through the metal space but around it and someone reassembled this wrong? So all the wires come down the door, goes into a little hinged plastic compartment, then go through a small gap with a metal bar. I wish I had a picture! I'm wondering if it should just go UNDER the metal bar if I can remove the bar, and not be constantly flexing through this 1/4" gap. I couldn't find anything in the manuals that had pictures of the SMU series, SHU yes, but not SMU.

So how can figure out what path it is to take. As I'd said someone else was in there first, and may have messed this up! Or do I just get some foam in the 1/4" gap it makes a 90° angle into to head back under the dishwasher.

Thanks for all your patience. I guess I could be more brief.

Your humble servant,

Tim

Whew! I'm tired of obsessing on this. Going to bed, but Gol, I love figuring this out and am so glad to have your help.

[Samurai Appliance Repair Man]

[user=28611]Tim M[/user] wrote:

Now do I have to order something special or can I just use foam adhesive weather stripping? I don't think anything was there before.

May not have been anything else there. You could add some dense, thin foam tape to provide some isolation from that mean ol' metal edge.

It has the (older?) harness like this.

http://www.repairclinic.com/SSPartDetail.aspx?s=t-296373-%3d%3di473256&PartID=473256

I saw that picture and it made my eyeballs hurt. I've not had the pleasure of replacing the harness in a Bosch d/w. :knifehead:

Whew! I'm tired of obsessing on this. Going to bed, but Gol, I love figuring this out and am so glad to have your help.

All is well. Sleep, my son, sleeeeep. :snooze:

[Tim M]

Back at the same job replacing an stove burner ignitor and putting the foam tape to protect the wiring harness. 

They mentioned that it isn't drying too well.  It's drawing 9.5 amps on the dry cycle.  Do you know what it should be?

 

Tim

 

 

[Tim M]

Ok now it looks like it draws 9.5 amps at the beginning of the dry cycle and then draws next to nothing.

[Tim M]

OK it draws 10 amps for the first minute of the dry cycle, then the timer advances one click and it's dead for the rest of the drying period.  I don't want to jump to a "bad timer" conclusion because someone else was monkeying around with this with no success before I started.

[Tim M]

Traced the wiring back from heater and thermostats to the timer.  Noticed a jumper that connects the heater to the both the upper and lower outputs from the same switch.  While the heater seems to get power during wash and rinse, neither the upper or lower spade have continuity with the power input after the first minute.  So I'm guessing that the the wheel must have broken inside on the dry section.

[RegUS_PatOff]

could be...

 

[Tim M]

Well, unless someone advises differently, he'll be getting a new diswasher.  After two wires going bad, the door switch and now the timer he's giving up on a 12 year old machine.

[RegUS_PatOff]

another Bosch ?

[Tim M]

I like them, I also suggested KitchenAid and Whirlpool, and said avoid Frigidaire.

 

One last thing.  The timer is always sending current to supply those switches isn't it.  There isn't any energy saver switch on this one, "just rinse and hold" regular, and "pots and pans"  So if the timer is working correctly, then it should be giving power to the element if it does so for wash and rinse?  Or should I be looking at the other buttons?