Hi All -
Last week my gas gauge died - pegged full when the key is turned on . Being that my horn went away about a month ago, I was thinking I had (another) issue with a bad ground. I also know from past experience with other Porsches, this is common if the ground is bad, or the sender is disconnected.
I did a pile of searching on the site, but some things seemed vague to me - and discsussions were either very old/locked or spread across severl posts. Thought I would pull everything I found after a several hours of work and post it here.
After reading everything I could, I decided to be anal and order a new sender just in case it was not a wiring issue. First I checked fuses and cleaned every flipping ground connection I could find on the whole bloody car. No change. Used my test light on the gauge and had power and ground. Had to be the sender or sender wire (which would have been a strange failure). I replaced the wire - no change. Has to be the sender. Pulled the sender and replaced it with VDO part number 221-021.
Still no change.... ugh.
So, there are several posts here referencing having to bend the float support. However, I attributed that to a clearance issue. The sender I pulled out looked 100% unmodified and in brand new condition. However, the float arm pointed to the drivers side of the car. The new senders float arm was pointing to the passenger side. Being that the sender is clocked (it will only bolt down one way) you cant just turn it on the mount. So I slipped the unmodified sender into the tank expecting some interference. It went right in! Before bolting it down, I looked inside the tank and could see that the tank was exactly the same left to right - so having the float on the passenger side should have no ill effect.... right?
Wrong.
Turned on the key and the gauge immediately pegged full again - ugh. I checked all of the wiring again - even used jumpers - and nothing would fix it. I grabbed the old sender and jumped it to the gauge - it moved the gauge (poorly, but it did move). Crap, was I the guy that got the one bad new sender on that the parts place had on the shelf??
I pulled the new sender and jumped it to the gauge. It worked perfectly - but BACKWARDS! lifting the float up pegged empty...…...
That's what the bend is for. For some reason the Chinese gauges and the VDO sender are opposites. I bent the float arm 180 and jumped it to the gauge before reinstalling - success!. As well, there are two tabs on either side of the float arm that can be slightly bent to ensure the gauge is accurate (as it can be at least....)
I now have a fully functional, *fairly* accurate gauge that sways a bit with the movement of fluid on corners, but does not bounce at all. Here is a down and dirty diagram of the bend needed - hope it saves another newbie some time.
now... about that damn horn...…..
