Tach Problem...GRR - The 1947 - Present Chevrolet & GMC Truck Message Board Network

71GMCer · 05-25-2010, 10:20 PM

Hey all,

I recently just bought a Tach. Nothing to fancy but i needed one because my truck never came with one from the factory.

So anyways...after hooking up the main wires... my truck will not start!

I have an HEI distributor and there was already a green wire that ran from the tach plugin and looped around the firewall then came back to this little plug...

If you can notice where i snipped the wire...but that doesnt seem to be the problem becasue i took the time to reconnect the green wire there and still no cigar.

Leviticus · 05-25-2010, 10:25 PM

From the picture it looks like you have no power to the dizzy. There are two blades where you hooked your tach up, one is the tach lead, and one it the hot wire for the dizzy.

The green wire you cut may have been your hot wire, and a poor color choice by the previous owner

Get some 10Ga wire and run from the "Unfused Ignition" slot on your fuse panel to the "Batt/Bat" terminal on the dizzy and you should be golden.

Hope this helps.

71GMCer · 05-25-2010, 10:28 PM

alright...well the two blades i belive were labeled...8+ and 8- or somthing or rather....and the instructions were to hook the green wire on the tach to the negative on the dizzy.

Leviticus · 05-25-2010, 10:33 PM

If you look at the picture, you will see "Tach" and "Bat" written on top of the dizzy cap. The same way you hooked the green wire to the tach side, you need to hook a ignition switched 12V lead to the Bat side.

Without this wire, no vroom vroom.

71GMCer · 05-25-2010, 10:48 PM

ah ok i think i figured it out...that plug in the fire wall seems to be a connector of some sort...the green wire was connected to it as well as a white wire....the green wire ran from the plug to the tach "batt" side of the cap....all i need now is some wire to run connect from where i snipped the old green wire to the Batt side of the cap and i should be rockin?

Leviticus · 05-25-2010, 11:06 PM

If you can, run at least a 10Ga wire to the dizzy, it does help. Glad you got it figured out.

71GMCer · 05-25-2010, 11:08 PM

alright..thanks for the help...why does it help with the gauge of wire?

Leviticus · 05-25-2010, 11:16 PM

Bigger wire=less resistance=better voltage delivery=better performance. Also make sure if you don't run a new wire and hook into your old one that it is not the stock wire with the resistor on it.

71GMCer · 05-25-2010, 11:50 PM

ya..im jsut gonna get some new wire and run it from that plug to the dizzy

05-25-2010, 10:20 PM	#1
71GMCer Registered User Join Date: Apr 2010 Location: Kelowna, Canada Posts: 116	Tach Problem...GRR Hey all, I recently just bought a Tach. Nothing to fancy but i needed one because my truck never came with one from the factory. So anyways...after hooking up the main wires... my truck will not start! I have an HEI distributor and there was already a green wire that ran from the tach plugin and looped around the firewall then came back to this little plug... If you can notice where i snipped the wire...but that doesnt seem to be the problem becasue i took the time to reconnect the green wire there and still no cigar.

05-25-2010, 10:25 PM	#2
Leviticus Shake and Bake! Join Date: Feb 2010 Location: Central Coast, CA Posts: 609	Re: Tach Problem...GRR From the picture it looks like you have no power to the dizzy. There are two blades where you hooked your tach up, one is the tach lead, and one it the hot wire for the dizzy. The green wire you cut may have been your hot wire, and a poor color choice by the previous owner Get some 10Ga wire and run from the "Unfused Ignition" slot on your fuse panel to the "Batt/Bat" terminal on the dizzy and you should be golden. Hope this helps. __________________ "All tyranny needs to gain a foothold is for people of good conscience to remain silent." Thomas Jefferson "You are remembered for the rules you break." General Douglas MacArthur "Support Our Troops And The NRA"

05-25-2010, 10:28 PM	#3
71GMCer Registered User Join Date: Apr 2010 Location: Kelowna, Canada Posts: 116	Re: Tach Problem...GRR alright...well the two blades i belive were labeled...8+ and 8- or somthing or rather....and the instructions were to hook the green wire on the tach to the negative on the dizzy.

05-25-2010, 10:33 PM	#4
Leviticus Shake and Bake! Join Date: Feb 2010 Location: Central Coast, CA Posts: 609	Re: Tach Problem...GRR If you look at the picture, you will see "Tach" and "Bat" written on top of the dizzy cap. The same way you hooked the green wire to the tach side, you need to hook a ignition switched 12V lead to the Bat side. Without this wire, no vroom vroom. __________________ "All tyranny needs to gain a foothold is for people of good conscience to remain silent." Thomas Jefferson "You are remembered for the rules you break." General Douglas MacArthur "Support Our Troops And The NRA"

05-25-2010, 10:48 PM	#5
71GMCer Registered User Join Date: Apr 2010 Location: Kelowna, Canada Posts: 116	Re: Tach Problem...GRR ah ok i think i figured it out...that plug in the fire wall seems to be a connector of some sort...the green wire was connected to it as well as a white wire....the green wire ran from the plug to the tach "batt" side of the cap....all i need now is some wire to run connect from where i snipped the old green wire to the Batt side of the cap and i should be rockin?

05-25-2010, 11:06 PM	#6
Leviticus Shake and Bake! Join Date: Feb 2010 Location: Central Coast, CA Posts: 609	Re: Tach Problem...GRR If you can, run at least a 10Ga wire to the dizzy, it does help. Glad you got it figured out. __________________ "All tyranny needs to gain a foothold is for people of good conscience to remain silent." Thomas Jefferson "You are remembered for the rules you break." General Douglas MacArthur "Support Our Troops And The NRA" Last edited by Leviticus; 05-25-2010 at 11:06 PM.

05-25-2010, 11:08 PM	#7
71GMCer Registered User Join Date: Apr 2010 Location: Kelowna, Canada Posts: 116	Re: Tach Problem...GRR alright..thanks for the help...why does it help with the gauge of wire?

05-25-2010, 11:16 PM	#8
Leviticus Shake and Bake! Join Date: Feb 2010 Location: Central Coast, CA Posts: 609	Re: Tach Problem...GRR Bigger wire=less resistance=better voltage delivery=better performance. Also make sure if you don't run a new wire and hook into your old one that it is not the stock wire with the resistor on it. __________________ "All tyranny needs to gain a foothold is for people of good conscience to remain silent." Thomas Jefferson "You are remembered for the rules you break." General Douglas MacArthur "Support Our Troops And The NRA"

05-25-2010, 11:50 PM	#9
71GMCer Registered User Join Date: Apr 2010 Location: Kelowna, Canada Posts: 116	Re: Tach Problem...GRR ya..im jsut gonna get some new wire and run it from that plug to the dizzy



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