broken tachometer

[dizzidave]

Like the title reads. 83 mini. How do I fix this? What is wrong. It works when it wants to, which is about once a month when it all of a sudden comes alive, then dies again 30 seconds later. Thanks

 

[2ndGenToyotaFan]

Sounds like your tack wire is grounded somewhere, it's pretty easy to run a new wire from the tach to the coil in the engine compartment.... I'm not sure where it hooks to on the coil, but I'm sure someone here does!

 

[WristPin]

a tach will work when connected to either side of the coil.

 

[2ndGenToyotaFan]

See I knew someone would know!

 

[Trevor]

My tach only worked when wired to the negative side of the coil.

 

[2ndGenToyotaFan]

I had thought negative too..... but I've only read about tach hook ups, the one I did put in my 86 toy pickup I just used the tach connection that was coming off of the coil.

 

[WristPin]

negitive is where toyota puts it, but it will work on either terminal.

 

[dizzidave]

Thanks, will check.

 

[dizzidave]

can anyone take a picture of the wire or location of coil. I looked but don't know nuthin' like you guys. I have factory manual and Chiltons, you'd think one of those would be helpful...but no,great if you're replacing tach in instrument cluster, but that's not the issue. Makes sense and all but need to actually find wire. Thanks mucho compadres.

 

[2ndGenToyotaFan]

Here's Wristy's video on the 20R coil, the 22R is probably just about the same, I'm sure Wristy will chime in on that one.

http://s93.photobucket.com/albums/l58/ultimatemeat/?action=view&current=Default-1.flv?t=1168408644

 

[KY854RUN]

If the 79 to 83 trucks are like the later ones, the tach wire comes off of the igniter. According to my 85 FSM the black wire from the igniter goes to the tach, A/C amplifier and the emission control computer. Bypassing the igniter, by running a wire directly to the coil, could burn out the tach if it is OK.

I would suspect that the tach is going bad. You can swap your instrument cluster into another truck to test it. If it works, then start checking the wire harness for any damage.

 

[WristPin]

Here's Wristy's video on the 20R coil, the 22R is probably just about the same, I'm sure Wristy will chime in on that one.

http://s93.photobucket.com/albums/l58/ultimatemeat/?action=view&current=Default-1.flv?t=1168408644

it is simalar but the wire colors and connectors are different. so referencing the 20R vid to the 22R engine would be challanging.