tach wiring harness. where to connect? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Gregsmx · 12-28-2003, 06:28 PM

I am upgrading my instrument cluster with a tach. The tach wiring harness has 3 cables:

Brown, which is a long cable and has a rubber firewall grommet on it indicating it goes into the engine compartment somewhere.

Reddish pink, which looks like it stays under dash.

Black. This is a ground wire.

Can someone tell me where to connect these 2 cables?

To make things more interesting, I am also installing a Painless wiring kit. Included with the under dash wire cluster is a pink wire labeled "Tachometer". So the question is which wire does it connect to, and where does the other go?

Thank you, Greg.

ElGracho · 12-28-2003, 08:34 PM

For the original harness, the pink wire plugs into the fuse box to an open "IGN" terminal and the brown wire hooks to the tach connection (marked "TACH") on your distributor cap.

apstguy · 12-28-2003, 08:47 PM

It seems like it would be tough, but once you find the terminal markerd TACH on the distributor cap, you'll wonder why it was so easy.

Shouldn't there be a 4th wire for the gauge light?

**N2TRUX** · 12-28-2003, 09:13 PM

This is funny! I just walked back in from doing the same thing on my 77. No, you don't need an extra lead for the lights. They are controlled by the dash lights...

Gregsmx · 12-28-2003, 11:13 PM

These boards are fantastic. Thank you all for the information. Sometimes what seems so difficult can be fairly easy. And the project doesn't have to be scrapped afterall!

12-28-2003, 06:28 PM	#1
Gregsmx Registered User Join Date: Jan 2003 Location: San Antonio Tx Posts: 338	tach wiring harness. where to connect? I am upgrading my instrument cluster with a tach. The tach wiring harness has 3 cables: Brown, which is a long cable and has a rubber firewall grommet on it indicating it goes into the engine compartment somewhere. Reddish pink, which looks like it stays under dash. Black. This is a ground wire. Can someone tell me where to connect these 2 cables? To make things more interesting, I am also installing a Painless wiring kit. Included with the under dash wire cluster is a pink wire labeled "Tachometer". So the question is which wire does it connect to, and where does the other go? Thank you, Greg. __________________ '75 Blazer RAT 4X4 "BLAZIN" - Custom frame off Here's the website I'm uploading pics to: Greg's frame off project

12-28-2003, 08:34 PM	#2
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,550	For the original harness, the pink wire plugs into the fuse box to an open "IGN" terminal and the brown wire hooks to the tach connection (marked "TACH") on your distributor cap. __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed

12-28-2003, 08:47 PM	#3
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,088	It seems like it would be tough, but once you find the terminal markerd TACH on the distributor cap, you'll wonder why it was so easy. Shouldn't there be a 4th wire for the gauge light? __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

12-28-2003, 09:13 PM	#4
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,023	This is funny! I just walked back in from doing the same thing on my 77. No, you don't need an extra lead for the lights. They are controlled by the dash lights... __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

12-28-2003, 11:13 PM	#5
Gregsmx Registered User Join Date: Jan 2003 Location: San Antonio Tx Posts: 338	These boards are fantastic. Thank you all for the information. Sometimes what seems so difficult can be fairly easy. And the project doesn't have to be scrapped afterall! __________________ '75 Blazer RAT 4X4 "BLAZIN" - Custom frame off Here's the website I'm uploading pics to: Greg's frame off project



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