Help needed speedo stopped working '88 300 SL

[richo]

Hi,

Urgent help needed as my car has its MOT on Tuesday and my speedo has stopped working.

I've had the instrument cluster out replacing a few bulbs, plus I took the dials out (very carefully) so I could clean off the dust on the inside of the glass.

However, I've just driven the car and everying works perfectly (rev counter, oil pressure gauge etc) except the speedo doesn't work.

It's a 1988 300 SL.

Any suggestions for what the fault may be and how I can diagnose it?

Help much appreciated.

Richo

 

[television]

Your car has a cable driven speedo does it not

 

[richo]

yep, it's a cable that plugs into the back, had three prongs I think

 

[television]

yep, it's a cable that plugs into the back, had three prongs I think

OK you have not located the square drive inner cable back into the speedo head or you have broken the inner cable

Undo the cable again and re try turning the inner one as you go

 

[Myros]

I think it might be electronic on the 88

it is on my 85. I had the same fun after i changed some bulbs. It turned out that the wires had just broken and corroded themselves out of useful existence at the kink by the connector plug. Solution was to strip the plug, easily done, and resolder some good copper from further up the wires back into the connectors. it only needed a few mm of wire stripping to find some good copper. Of course, I had gone a bought a replacement speedo only to find that didn't work before I used some common sense and asked around for the right answer.

 

[stever]

For reference, you don't need a working speedo to pass the MOT.

 

[richo]

Many thanks

Thanks for all the help and advice - got it working again. Fingers crossed for the MOT tomorrow.