89 k2500 speedo

[hammertime371]

has anyone had trouble with the speedo stop working on an 89 k2500. occasionaly it just stops working while driving. I notice it because the tranny unlocks the converter. a simple smack of the dash board and it starts working again. it has done this for years. ive taken the cluster out and checked for bad connections and such but no luck. it must be a problem in the guage itself. any ideas?

[black dawg]

It is weird that smacking the dash gets it to work again. In that body style, the ecm would get vss before it goes to the cluster right??

[EagleMark]

IIRC that truck would have turbo 400 or 700R4 and a VSS still behind speedo, now if it were 4L60E or 80E then VSS would be in trans and differant ECM/PCM. Actually I don't think the E trans was even out then... but was in later years of that body style.

[hammertime371]

its a 700r4. the vss is on the transfer case i believe. its a 4x4. but even so if it was vss how would smacking the dash make it work again?

[EagleMark]

Fear?

If the VSS is not back there then I'd say a wiring issue, but would really look gfor the DRAC. This is where the VSS signal is sent and adjusted for outputs to Speedo if Electronic, CC, ABS etc...

[jameslleary]

E trannys didnt show up in trucks till late 93.
smacking the dash like something came loose. I would take out the VSS and gander at that too, just for the heck of it.