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hypoxia · 10-13-2019, 01:59 PM

I removed the potting from the Sauer Danfoss fan controller which I removed a couple of years ago due to the fan in high speed continuously. I soldered the Orange and the Yellow wires at the PC board with the assumption it may be a bad or cold joint. I installed it into the coach and it is operating normally again! It needs further testing but is a step in the right direction.

ZackMan · 10-13-2019, 04:05 PM

hypoxia,,

I recently had the issue of the fan running on high speed intermittently. I replaced with a new Sauer Danfoss Fan Controller and have not experienced anymore issues.

Is this your first repair of the Sauer Danfoss wherein you performed the soldering? I probably could have saved the money expense if I knew about this.

What did you use to reseal the top of the circuit board?

hypoxia · 10-13-2019, 04:38 PM

Quote:

Originally Posted by ZackMan

hypoxia,Is this your first repair of the Sauer Danfoss wherein you performed the soldering? I probably could have saved the money expense if I knew about this.

What did you use to reseal the top of the circuit board?

I stole the idea from Bill G on the Yahoo Monacoers forum. He repaired one in a similar fashion so I thought it would be worth spending some time on. I have not re-potted it and plan to leave the new one unplugged but attached to the hydraulic valve and zip tie this one by the tag axle air pressure gauge for testing.

I used an X-Acto knife with a chisel blade to remove the potting. If I end up using it full time I may tie it up as high as possible to keep it out of the moisture as much as possible. There's no reason to keep one mounted on the hydraulic valve.

I thought it was worth posting about now before a thorough test in case someone was about to purchase a new controller.

vito.a · 10-13-2019, 06:48 PM

Wow, great job! I'll send you my controller.

tompn · 10-18-2019, 09:22 AM

I read an article on replacing the batteries for an in tire TPMS sender and they re-sealed it with hot glue.

Just a thought.

Tom

Captjake1 · 10-18-2019, 09:31 AM

Plastidip also makes a spray designed to coat electronics. Used it on an electric trolling motor and worked well .

Jobert · 10-19-2019, 06:57 PM

I recently replaced our controller for the same reason, but always felt it was an open condition resulting from a broken wire or junction. I could go out and wiggle the wires and it would cut the fan down to the correct speed and was usually good for anywhere from a day to a month. This went on for about 5 years. It just got less predictable so I replaced it, and it is my plan to do the same thing, rewire it and see if I can find a break or open or something, and save for a spare. Good job and will be lots of help. Thanks for sharing. Happy Trails Bert

hypoxia · 01-11-2020, 10:08 AM

My repair ended up not working, the fan control is still intermittent. I decided to open it up so I put the end mill to work.

The red wire had an intermittent solder connection but that didn't cure it. I took the plug to the solenoid apart, it had lots of corrosion. I don't think it is the problem though as it ohms checks good. It controls a 12 VDC solenoid so I'll try to see if any voltage is there when I get time.

I plan to put my other controller in the mill and remove enough metal to access the solder joints in it as it is now intermittent.

hypoxia · 01-11-2020, 10:15 AM

vito.a · 01-11-2020, 10:29 AM

Thanks for posting. How many controllers do you have?

hypoxia · 01-11-2020, 11:30 AM

Quote:

Originally Posted by vito.a

How many controllers do you have?

Two total. The voltage this one puts to the solenoid is 13.8 volts, I will check the "good" one soon, I assume the voltage should be variable to partially open the hydraulic valve.

153stars · 01-11-2020, 11:52 AM

In the last pic 3rd and 4th wire down looks like trace on circuit board go to f11 f12 "maybe smd fuses ???" across/connected to them . I have found cracks or burnt traces on a C.B. and just soldered down jumper wires to replace them.
Once I garbage picked a nearly new $1500 Yamaha electric piano. If I bent the 12" X 12" circuit board mounted on standoffs, it worked perfectly. Went over and over it with jeweler's loupe and meter . I couldn't find any bad trace or solder. I just added another screw without standoff to bend the board LOL. It worked for 15yrs until I put it out for someone else to pick up, after my daughters didn't want to play it anymore.

hypoxia · 01-11-2020, 04:26 PM

Quote:

Originally Posted by 153stars

In the last pic 3rd and 4th wire down looks like trace on circuit board go to f11 f12 "maybe smd fuses ???" across/connected to them .

They ohm check good, unfortunately.

153stars · 01-13-2020, 09:28 PM

Well nothing ventured nothing gained. If you have ever stripped a wire you know the insulation stretches quite a bit. So if wires are stressed to controll, the wires being potted 1/2" may not add much of a strain relief for the copper to PCB solder joint. If I had this on my rig. I would make sure there was no strain or movement at the loom.