I Have An 03 Gmc Truck With The 5.3 And I Just Installed The A 5" Tach On It. I Attached The Green "coil Wire" To The White Wire On The Back Of The Guage Cluster And I Am Only Getting Half Of The True Rpm. I Need To Know Has Any One Had This Problem And How Do I Fix It?

 

read the instructions. with these trucks you have to read the 4 cylinder instructions. can't remember how many wires you have to cut though.

 

yeah, go figure.... the LS1 style motors require you to run the tach as a 4 cyl. setup, something to do with the reading vs. the individual coil packs

 

So Run It As A Four Cyl. And Cut Both Wires? Whats The Reasoning For That? Ill Go Cut Em Now But For Future Reference - Why?

 

Thanks For The Help Guys It Works Like A Charm Now. Finally A Site That Offers True Assistance. Thanks Again

 

no prob buddy. glad it worked out for you.

 

which wires did you cut?

 

I Used The Autometer "autogage" Series (the Cheapest) And Cut Both The Orange And Brown Wires. This Set It Straight And Thanks Again For The Help.

 

Got any pics of where you mounted teh tach? Just curious, because I got rid of my small digital tach and am now thinking of going with an autometer c2 to match the rest of them. I haven't found a place i like to mount it yet, though.

 

Sorry, No Camera Or Scanner Here. I Mounted It On Tha A-pillar With These Little Foam Blocks On The Backside. I Got The Blocks From Hobby Lobby. My Concern Was That The Plastic Piece Wouldnt Hold Up. The Blocks Are About 1/4-3/8" Thick And Have An Adhesive On The Back. They Hold Well And There Is No Flimsyness Whatsoever On The Pillar Cover. Worked Out Really Well. I Ahve Also Seen Them Mounted On The Trans Hump Pointing Up At The Driver, Just For Your Info.