HELP FIX MY TACH PLEASE...

[BPTTONE420012]

my 1982 mc had no tach wire ran to the gauge cluster plug... ran a new wire to #17, and now the tach works but its way off... reads 4 grand when at an idle and travels up from there, almost like its set for a 6cylinder not an 8... i heard somewhere about a jump wire or something to switch between 6 and 8... help please...

ACTUAL PICTURE OF BACK OF MY TACH...

 

[ssn696]

The tach wire I pulled came with a silver cylindrical condenser on it. Can't find it or even good picture at the moment. If you just ran a wire straight from the tach plug on the HEI, that may be the source of your issues. Long shot here, but you may be able to modify this harness from LMC truck (36-1885) if you can't find one for a G-body.

 

[BPTTONE420012]

The tach wire I pulled came with a silver cylindrical condenser on it. Can't find it or even good picture at the moment. If you just ran a wire straight from the tach plug on the HEI, that may be the source of your issues. Long shot here, but you may be able to modify this harness from LMC truck (36-1885) if you can't find one for a G-body.

yeah i know it was suppose to have an inline filter/resistor, so i bought a bunch of 100k ohm 1/2 watt resistors, but have not tried them yet... thought it might be more of a wrong setting thing, cause i know my after market tach acts like this when the switch gets switched to a lower setting... and i had heard something about soldering a jump wire an the back of the tach somewhere, but i forget where i heard it, might of been a pontiac forum...

 

[drogg1]

Edited:

If I remember correctly, all you need to do to switch between a V6 and a V8 is move a jumper on the back of the tack to the spot right next to it. It might even be labeled. This may be the root of your issue.

Perhaps this article will make more sense:

http://www.442.com/oldsfaq/ofmsc.htm#MISC Tic Toc Tac

Here is the schematic showing the filter:

http://www.maliburacing.com/wiring_diag ... ackage.jpg

I highly doubt you absolutely need the filter. I would not think the absence of it would cause the behavior you're describing.

If neither of those prove to be the problem, there may be something internally wrong with your tach. If you have a little basic electrical circuit knowledge and are willing to learn/do a little soldering, here is an article detailing the likely problem and fix:

http://www.montecarloss.com/community/u ... Post646206

Also, I'm not sure why the tach would be in the V6 configuration as I don't think SSs came with V6s?

I hope this helps. I'm sure someone else will chime in tomorrow. Or maybe you can private message member pontiacgp. He knows how most if not all of the circuits in our cars work.

Good luck.