speedometer doesn't work

[jimmy4x4]

i have alot of problems man but i paid $600 for my jimmy and it's been good to me so if you can tell me why my gauge doesn't work i might just give you a big kiss.

[BlazerLT]

please supply all information.

[jimmy4x4]

the needle and tach and mileage don't move

[BlazerLT]

no, I meant the year, the engine, the truck, did you do any repairs that might have caused it?

[jimmy4x4]

oh my bad its an 85 2.8L V6 and i bought it broken
but i got everything else in it to work except the speedo oil gauge and rear defroster

[BlazerLT]

Originally Posted by jimmy4x4

oh my bad its an 85 2.8L V6 and i bought it broken
but i got everything else in it to work except the speedo oil gauge and rear defroster

I think it has a vehicle speed sensor located on the rear of the tranny to measure the speed.

[jimmy4x4]

i'll check that out thanx

[danjgrace]

You sure got a great deal on your Blazer. Its basically the same truck as the Jimmy. The only other trouble I have had was the rear latch switch was running my battery down. Found a lose ground wire. Also the battery and alternator went out this past year and after the second alternator, I found a loose block ground wire from the battery causing all of it!

[rlith]

Actually you don't have a speed sensor in the 85, you have a gear (as your speedo is cable driven). To check the cable, pull the cable off the tranny and hook it to a drill, fire up the drill, if your speedo moves it's your speedo gear on the tranny, easily replaced. If it doesn't move it's most likely either the cable is bad or fell off the back of the speedo behind the cluster. As to your tach check the wire with a multimeter to your coil. Probably a break in it somewhere...I don't have access to those diagrams for your year but any dealer should let you look at their books..