Bouncing Speedometer- How to fix?

[944jeff]

'86 NA... My speedo sometimes works: fine/bounces/not at all. Could it be the cable or hall sensor or the guage itself? Waht is most likely the problem? Coincidentally my odometer doesn't work but that is surely the plastic gear. Thanks...

[mambodave]

new speedo cable probably.

But check the seat on the back of the gauge first before you by a cable.
There not cheap.

[944jeff]

$30 for a cable here at Pelican> I wouldn't call that expensive. What about the speedometer impulse sender? Could that cause an intermittent problem? Thanks!

[mambodave]

not sure there.....

I guess I got lucky.

$30 isnt bad. I think I paid $75 for mine at a local shop.

[mikemurcia]

The late (like your '86) 944 speedo is not cable driven. There is a sensor on the tranny that picks up your speed. If the car in question is truly an '86, there is no speedo cable.

[Cebu]

It is most likely the speed sensor on the transaxle

[mambodave]

Sorry man, Forgot i did it on the early 944.

[scheistermeiste]

how about on my 88 924S, the 924Ss are the same as early 944s right? if so mine would be a cable.... if im right...

[1.2gees]

Yes, the 924S uses a cable as well.

PS: If you don't mind an extra long cable, a lot of VW cables will fit. If the bouncing is extreme, the problem is likely internal to the speedo.
Ahmet

[944jeff]

The bouncing is not extreme. It does not peg to the max side, usually just past the actual speed and then down to zero. Which sensor are you describing, the hall sensor or the impulse sender? BTW, the car is a 1986 MY. Thanks guys!

[Cebu]

The Speed sensor/sending unit is located above the left rear wheel drive axle where it attaches to the transaxle. Has an electrical plugged into the sensor or sending unit.

[Trevor]

Mine will sometimes stick at 0 then catch back up after a few seconds. Does that mean something is wrong with the sensors or is it most likely the guage?

[944jeff]

Trevor, mine is doing the same thing. I think this is what we need to replace, "speedometer impulse sender", right guys?

http://www.pelicanparts.com/catalog/images/electrical/94460621000.JPG

part # E-606-210-00 ($54.25 at Pelican)

[Trevor]

I think I can live with it....

[bull4u2me]

my speedo/odo stopped working. A mechanic suggested replacing the impulse sender.

Heres a list things of what could have gone wrong....
1) the impulse transmitter
2) the wiring/clips along the whole speedo setup, from the transmitter to the instrument cluster
3) the speedo cluster itself (which I hear, very rarely screws up),however you can purchase a second hand one on ebay for around 150$.
4) there could be a problem inside the transmission itself (where the sensor is attached to).

I guess there could be more places things could go wrong, but from what I hear, its usually the transmitter that quits first.

Till then the only way to judge my speed is with the rev meter (with the 3 speed auto its rev X 2 = approx speed in mph).

So Cal... is there a way I could test the speedometer cluster myself?