THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

Okay. Dug a little deeper but had to stop. This is the sending unit, not sure how this puppy is installed or removed? I tried the lower nut, it moves about 1/4 turn before stopping and the textured piece above it does not move, at least not with the force I'm comfortable using.

I looked up some troubleshooting and got the old volt meter out to measure the red & black wires from the sender. At first I got nothing with the wires pulled from the gauge, hooked everything back up and tried again and got 14v. This was different.... Possibly a ground, I am going to re-look at the wires, clean up grounds and test drive (it got late last night) and will report back.

In the meantime, does anyone know how this sender is installed or removed? Most manuals I see online only talk about the gauge.

The sender has a knurled nut (on the right in your photo) that is screwed to the larger nut (on the left in your photo). Hold the left nut with the appropriate wrench and use a channel lock pliers to loosen the knurled nut.
>> Don't lose the short piece of inner cable that fits into the sender <<

https://swissarmyvehicles.com/pinzgauer ... nic-mphkmh

The electrical cable to the sender is easily abused by road dirt, stones, etc. and may be shorting out. If thats the case, after you repair it and reinstall, I suggest covering it with a section of plastic cable sleeving.

I am thinking you hit the nail on the head. I was able to get the unit out off of the truck (thank you!) and it appears the black wire (ground) has lost it's insulation right where you indicated the wear spot is. I can imagine this is the root issue. I guess I will play around and see if it is something that can be repaired, but I can see (at least) a new sending unit in my future.

Well iused to have a terratrip 303 computer in the orange buggy i build a long time ago and i had a simelar unit like in the picture ...but i had that sender mounted just behind the spedometer in the dash.....never had to worry about these problems like dirt or rocks

The other common failure mode for the VDO Speedo's is the LCD display.

These can be repaired -- as a DIY.

How to replace: https://www.youtube.com/watch?v=PFkSwD5-mfw

Where to source a LCD:

https://www.autoecupart.net/products/vd ... gKzYfD_BwE

https://www.ebay.com/itm/333673118882?_ ... gKkZ_D_BwE