broken speedometer

[Riccardo]

Hello,

My speedometer has just broken and I am not sure why or how to fix it. It had been wobbly for a while (see previous post) but today it finally stopped completely. Even the odometer is not working anymore.

Can someone tell me what I need to check and where I need to look?

The car in question is a 1986 Thema 2.8 V6 with manual transmission.

Thanks in advance for any help.

Best regards

Riccardo

[Villads Bønding]

You can find a lot about this topic in older topics. It´s a wery common Thema problem.

[Mark]

Yes it is a very wery problem with these cars, the place to look is the voltage stabliser, the little white box on the back of the instrament panel, these quite often blow a component, if your good with electronics you can repair them, if you can locate the right parts, usualy the diode(little square black thing with two wire legs) and one of the resistors(cylinder shapped thing with two wire legs), more than often the speedo will just read one speed, around 110-120 mph range, its these that have gone. Hope this is some help, if not it's a new one, if you can find one, or a replacement instuument pod, which is expensive!

[Rustam]

Hi Mark,

My speedometer have not worked for a long time. Today I unmount that white box (voltage regulator) which you mean in your message and found that one of diodes is cracked and transistor has convexity becouse of overheating.

Do you remember the nominal value of the diod (transistors is readable)?

Sincerely,
Rustam