Height sensor repair?

[Moridinbg]

Can this be repaired somehow? The contact patches have worn out. Readings are all over the place. +180mm, -20, +37, etc.

The brushes and springs on the sensor are good. It has already done 400 000km, so it is kind of expected, but I want to try to fix the contacts before throwing $200 at a new one.
I Couldn't find used ones around me.

 

[Moridinbg]

I went ahead and tried to repair the contact patches almost successfully. The weird thing was that when I measure for continuity with a multimeter the black tracks, where the brushes glide, are not conductive at all. Couldn't measure any resistance either. The only conductive part are the circular patches. There is no continuity between the first and third patch either?! I am a bit confused as I thought this is a potentiometer and I was expecting the tracks to be conductive?

Anyway the patches were giving bad contact so I applied some silver conducting paint. This things flows and dries very weird and I wish I tried some elsewhere first.

I also applied some to the ends of the springs, where they contact the patches. Everything measured OK.
When I put it back on the cruiser it didn't work and the OFF light was blinking Techstream showed C1713 - Rear Height Control Sensor Circuit. Rear height reading was stuck at 181.2mm and the sensor went from giving random readings to being stuck
This puts the AHC in safe mode where it adjust by pressure - aims for 6.5MPa front & rear. With Kings springs this puts the rear slightly higher than normal. At least it's drivable that way.

I went for a few rides for about 200km this way and at one point the AHC just started working??? Techstream shows normal rear height values and pressures, truck moves L-N-H.
At this point I haven't yet done the FSM test with applying 4.5V and measuring voltage across the sensor range. I guess the sensor made good contact again, but who knows for how long . I am going to drive like that until the new sensor arrives

 

[LndXrsr]

I believe there are conductive materials under the black "tracks," so likely something isn't in continuity under there if you have nothing between 1 and 3. I could be mistaken. Admire your endeavor, but I'd just replace it.

 

[uHu]

I've bought some cheap sensors on AliExpress.It looks like they work just as well as the originals.

 

[Moridinbg]

So I ordered a new replacement. The repair worked for 500-600km and then went back to AHC OFF.
Really wanted to repair the damn thing instead of paying $250 for what is a couple of worn contact patches...
I saw the aliexpress and amazon sensors, but I really do not think I can trust that they won't give up in the middle of nowhere...

 

[medtro]

I've bought some cheap sensors on AliExpress.It looks like they work just as well as the originals.

Thanks for posting this. How many miles you have on them?

 

[uHu]

Thanks for posting this. How many miles you have on them?

Don't know, I don't have presise info, but it seems to me that the height sensors will last about five years regardless of make. I have changed to OE, to Dorman from Ebay somewhere, and now the latest from "Likes Autoparts Store" on AliExpress. For my driving on salted roads for half the year, the most important issue is how well sealed the sensors are. Often the lid (with the carbon trace on the inside) will not seal perfectly to the house of the sensor - because the lid is too soft or the O-ring too hard.