Porsche Enthusiasts Club Forum

Hi all,

was driving my S2 on the motorway last night and the speedo suddenly started bouncing wildly from 0 to 70 - then dropped to 0 and has been there ever since

It did do this a year or 2 ago but normal service resumed a few seconds later - not this time sadly.

Whats the best place to start - dash end or wherever the sensor might be?

Thanks

Sensor on the gearbox or connections on the cluster, or a dry joint on the motor module on the speedo head

Eeeek....

Pulse sender for 944 • 1991 • 944 s2 • Cabrio • Manual gearbox, 5 speed
Rose Passion price list 600,00 € Inc.VAT

I would just clean the connections first before you panic, and while your looking at it, you might find a VDO number or something on the side

Most of these thing are not unique to Porsche

Thanks Waylander,

Ill take a look at the weekend.

I finally got around to looking at this over the weekend. Took the cluster out and checked all connections which seemed fine. Then located the sensor and disconnected and checked the electrical plug - again looked OK.

Test drive resulted in no change so I guess its the sender unit

Does someone know what size the hex nut is on the sender?

I only had 19mm which is too small and an adjustable that is too bulky to get in there so Ill need to buy a spanner.

just buy a full set, 6mm up to 32mm, but if 19 was too small they tend to go up in 2mm jumps so 21mm

A couple of questions....

How does the plastic sender separate from the nut - does it unscrew seperately or do I need to take the whole thing out to separate them?

Can I test the speedo by applying a voltage to the pins at the sender to it to see if the speedo reacts?

It’s one thing threaded with a lock nut, I believe there is a drive flange in the end, don’t know if you can put any bolts through it

Had another go at this over the weekend. Dash out, cleaned the "rugby balls" again and also all the ribbon connectors with no joy. At omne pont the tacho also went off but after a bit of messing with the connectors thats back.

No amount of messing with connectors seems to fix the speedos though

Checked the connection on the sensor again and it looked OK.

Managed to unscrew the sender and confirmed that the plastic drive spindle is turning OK so its not a mechanical issue.

Problem is I damaged the small circuit board in the head of the sender when removing it - theres a square white electronic component that has broken off - I guess it could have been damaged already but more likley my clumsiness.

Either way, its not going to work now so im going to need a new sensor.

I can only see new ones at £500+ which seems OTT when a similar VW unit is less that £20.

Ive attached a pic of the parts showing the broken component and where it came from.

The black plastic part has what looks like a VDO number on it 214/1/5 12v IMP but I cant fine this on the VDO site

If anyone has any ideas on where to source a replacement feel free to share !

Could it be

https://rennlist.com/forums/924-931-944 ... ender.html

I would have a good search breakers and give places like EMC a call they don’t break often

Just seen this pop up on eBay

https://www.ebay.co.uk/itm/295191103277

Thanks guys,

I have sourced a s/h unit at £75 so hopefully that will sove the problem.

good find!

Just to add, I did ask my OPC and they said they are NLA, but were £86+vat when they last had them. Looks like Rose Passion are definately taking advantage of the fact thay have a few in stock!!