hey,
I just bought an 88 supra turbo about two weeks ago, its great, new engine, nice solid car. I'm not very familiar with this car yet, but i'm getting there. when i bought this car, the speedometer didnt work. the guy i purchased it from told me that the short cable behind the dash was broken, so i took it to a shop. the shop was driving down the road with my speedometer working, and all of a sudden, it stops and drops to zero again. they say that the long cable in the back is broken now. I have them replace that, a couple hundred dollars the speedometer is still not working... i have another speedometer that the guy i bought it from included with the car, but when i installed it, it still didnt work. Is there anything i should look for, any moving parts behind the dash/speedo? I'm not sure what else to try. Any help would be appreciated.

well....if i were you...i will disconnect...both end of the cable....n spnd. the cable inside n see if its spnding... if it does then.... thats good... well i not sure bout mk3 but on mk2 sometime...the trainy have a little adapter to the trainny....if you have that little adapter then its better for you to took that one out...n do the same on like the cable...usually...thats the one that caause the speed cable by not moving or not working....so you need to check on that adapter too...from the mk2 that adapter is like an L shape or it bent like a 90* so yeah...hope that work for you...cause i have this problem on my mk2 before...so i think it might be the same on ur too but i not sure....hows the mk3 tho...this one day i drive from 209 area to 559 area in cali....n on the highway 99 going south....n i went half way to my point b n my speed just stop....n it didnt move...so when i came back home n i check n the cable is no good n i check the adapter n the cable in that adapter is broken n it cause my speed cable damage...so i went to the junk to get myself a use cable n the adapter....n i replace n it do it... so hope its same problem like me...n hope you get to work...n have a good one...