Square Door Hoover Logic 1300 Wont Spin

[a3620]

Evening folks, I wonder if anyone can point me in the right direction?
Our wonderful old Square Door A3620 Hoover Logic 1300 has stopped spinning!
I fitted a new "old stock" motor 18 months ago while fitting new bearings etc.
All of a sudden, neither the G 1300 spin or the N 600 spin are working.
The drain pump is working properly and all other programs seem to run as normal.
I’ve tried gently rocking the program knob but the drum just turns at the normal wash speed.
I removed the motor brushes, they have plenty of meat on them (only 18 months old of course) they move freely and the commutator looks mint.
I put my meter across the tachometer, and the meter fluctuates as I turn the motor by hand. Admittedly not a conclusive test, but it suggests continuity. I also checked all the spade connectors etc.
Took out the motor controller board and couldn’t see any obvious dry joints etc. Again, I know this doesn’t mean it isn't faulty.
Finally I re-seated and checked all the plugs on the timer/motor etc.
Normally, I would just buy a new motor, but it's reasonably new. Could it have failed so soon?
Ideally I would start substituting parts, but this is obviously impossible with the now rare and expensive parts, so I'm unsure what else I can try?
I don’t think it’s the timer, because neither 1300 or 600 programs work and I would have thought a "dodgy" contact would have shown up as an intermittent fault. Am I wrong?
I'm tempted to buy another motor. Question is, do these symptoms sound like the motor controller, or the motor itself, or am I barking up the wrong tree entirely?
Is there anything else I could check, or should I just ring the scrap man?
Thanks in advance
Chris

 

[keymatic3203]

Hi Chris

Just a few quick thoughts, if the motor turns the drum correctly at wash speed, then the motor and tacho circuits are working, have you checked the pressure switch/pressure vessel and the out of balance micro switch, as if the machine thinks it still has water in the tub or is out of balance it will hold the speed to distribution.

But essentially it doesn't sound like a motor fault.

Mathew

 

[a3620]

Brilliant, thank you so much for your reply.
No I haven't checked either, so will have a look now, and let you know.
Thanks again, really appreciate your help.

 

[a3620]

The out of balance micro switch seems to be working okay. If disconnected the drum stops tuning all together.
I tried blowing down the pressure switch tube and it's all clear. If I blow the other way the switch clicks (so no air leaks) but I didn't test this any further.
Then I tried another spin and it seems to be working again and I cant recreate the fault.
I can only suppose it's a loose connection or dry joint somewhere.
One thing was wondering. When the lid was off, I playfully tapped the timer with my screwdriver handle. Could this be the problem? I noticed one of the timer motors felt very warm. Is this normal, maybe something is (or was) stuck?

 

[sesteve]

Hi Chris

It’s likely that the pressure switch was partially blocked and by taking off the tube and blowing you’ve cleared it. It’s a common fault on these and doesn’t take much crud to stop the switch operating correctly so the machine still thinks it’s got too much water in it. . Might be worth checking the sump hose where the pressure vessel is and cleaning it out.

 

[a3620]

I see where you're coming from about the pressure switch, but it was completely stripped and cleaned 18 months ago, and when I blew down it yesterday, there was absolutely no resistance.

Any thoughts on the warm/hot timer motor?
The machine was only powered on for 15 minutes, but it felt as warm as a cup of tea.

 

[sesteve]

One of the timer motors runs continuously so would get warm although I’ve never noticed how hot they get. It could be that the cam is not rotating as freely as it used to and the resistance is putting a strain on the timer motor. I recently took apart a Servis timer and used electrical contact cleaner and lubricant which stopped that one from sticking. However, it sounds more like the pressure issue to me given you couldn’t get it to spin on either section of the programmer. Did it do its interim spins?

If it happens again, check the contacts on the pressure switch - the connection that goes to terminal 8 on the module is the one that needs to make to allow the machine to spin

 

[a3620]

Ahh, I understand what you mean. Thank you. Sounds like the pressure switch then.

The mounting screw for the switch was very loose, so it had been rattling all over the place. I wouldn't expect this to affect the switch performance, but maybe??

It's currently spinning away beautifully with a full load as we speak, so I will just have to see how it goes.

If it starts playing up again, I will suspect the switch, although I have no idea where I would find a replacement. Is adjustment difficult?

Can you tell from my picture, which wires I would need to test if the level switch starts sticking? You said "terminal 8 on the module" do you mean the switch module?

Many thanks again, your help is truly invaluable.

 

[gizmo]

I've never worked on one of these machines, but pressure switches are quite unreliable devices and are often replaced. They seem to "drift" over time in calibration.

 

I had two identical Askos that did the same thing - refused to spin due to slight blockage of the hose to the pressure switches - the Askos in question have two separate pressure switches, connected to a single hose via a Y-connector. Blowing down the hoses cleared them, and there was no obvious blockage. It only takes a very slight accumulation of muck to restrict them. Don't be surprised if they work perfectly for years now you have cleared the hose and chamber.

 

That design shown in the photo, where the pressure switch attaches to the drain hose, is asking for trouble - it means very dirty water gets into the pressure chamber and hose. Better designs (like older Hoovers) have the pressure chamber with its own separate connection to the drum, quite distant from the drain.

 

[sesteve]

Avoid adjusting these if possible- they are set precisely and can be messed up quite easily as there are usually a few different adjustments for the different levels and adjusting one can mess up the others. With these machines is usually the air path that’s the issue rather than the switch itself. As Gizmo says it’s not the best place as fluff and un-dissolved detergent can get pushed into it.

According to the service book, it’s connection 13 on the pressure switch which should be a brown/grey wire. When the machine is empty, there should be continuity between 11 (also brown/grey)and 13 on the pressure switch.

The module is the little unit at the bottom of the machine on the opposite side to the pump as in the picture.

Hope this helps
Steve

 

[sesteve]

Correction

It’s green/brown for the wires - I misread the code

 

[sesteve]

Just to be clear it’s green/brown on connection 11 and grey brown on connection 13.

 

[a3620]

That's absolutely fantastic. Thanks' so much everyone.

It seems to be working ok again now, so hopefully just a but of fluff in the pipe.

Your kind and generous help means I understand the machine a little better, and I have all the info I need to diagnose the switch, should this happen again.