[EdCarpenter]

I am in the finishing stages of my 70SS restoration. I have the original in dash tach. The tach is not working. I traced the brown wire to the coil, negative side. My quetion is, will I have to modify the wiring with a petronix pick up in the distributor?

Please give me some pointers on where to start.

Thanks!

 

[Chevl_Steve]

Hey Ed! how's the south treating you?

The negative side of the coil is correct. Are you sure the wire is good and not broken? Did the tach work before?

I put one of those Petronix modules in my 58 truck I bought and it crapped out very soon after the first run. I sent it back and had it replaced by a different brand name unit.

I don't have a tach in the truck though, so I am not sure about the signal being right for the tach. You might have to contact Petronix.

Steve

 

[EdCarpenter]

Steve,
Sorry it took so long to respond. I'm about tired of winter. We had about 2 weeks of below 30 degree temps at night and it was only reaching the mid 40's to low 50's at that time. At least now we are seeing the 60's and 70's. My 2 months of winter are coming to an end. HA HA.

I traced the tach wire back to the dash plug and found I have good wiring. The printed circuit is new and, as you know, the car was in pretty rough shape before the restoration. The tach may have never functioned for years. I just ordered a replacement tach for the time being and will save the original for restoration.

I just hate having to remove the dash to the point I can replace the tach.

The petronix fires the tach in my tach / dwell meter fine.

I hope the replacement tach does the trick.

 

[70ss427]

I am having the same problem with my Tach, when you jit the key to start the tach goes to 1400 and stays??? doesn't move when engine is running, but then goes back to 0 when key is off???

 

[70ss427]

I guess I should say that it is an original Tach 70 chevelle gauges SS