tac wiring question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MARIOS68PANEL · 03-16-2012, 08:24 PM

I would like to wire in my tac .I didnt see it on the wiring diagrams the are posted. Can some one tell me the ins and outs on wiring the tac.

jjtackleberry · 03-16-2012, 08:28 PM

DittoPosted via Mobile Device

treveiger · 03-16-2012, 11:59 PM

Same here lol
Posted via Mobile Device

Sport/Truck · 03-17-2012, 10:16 AM

IIRC it a single wire that runs through a specific hole in the fire wall.
s/t

bmfm64 · 03-17-2012, 10:44 AM

It's a two wire set up. One goes to a switched spot in the fuse panel and the other goes out to the distributor or coil depending on points or hei dist. I also ran a ground wire from the stud on the back to the dash. Try searching more, this is were I found how to wire mine. If nothing else you can buy a repro harness that's plug and plug from any of the big suppliers.

MrSchaeferPants · 03-17-2012, 12:32 PM

3 or 4 wire depending on your tachometer.

Probably a White/Red/Black/Green setup, on a lot of aftermarket tachs, the 4th being white, for a lighted tach, if applicable.

Red -Switched 12v from panel/block/wherever.
Black - Ground
Green - Dist-Hei-Coil hook up. (Labled 'Tach' on most Hei's, not sure about a coil)
White- Lights, splice in junction with dash lighting past the dimmer

Not sure if you have a general aftermarket tach, someplace there's settings for 4,6,8 cyl that has to be adjusted.

bmfm64 · 03-17-2012, 01:28 PM

Good call, are you trying to wire in a factory tach or aftermarket tach?

**special-K** · 03-17-2012, 01:45 PM

Factory or aftermarket/points or HEI?

jjtackleberry · 03-17-2012, 02:13 PM

Factory points
Posted via Mobile Device

MARIOS68PANEL · 03-17-2012, 02:22 PM

Thanks all. Got it wired and it working fine . Stock tac - HEI dizzy- two wires. one to fuze block ond to dist cap = perfect

MrSchaeferPants · 03-17-2012, 03:14 PM

Quote:

Originally Posted by bmfm64

Good call, are you trying to wire in a factory tach or aftermarket tach?

Yup, should of been what I asked first.

03-16-2012, 08:24 PM	#1
MARIOS68PANEL Active Member Join Date: Mar 2005 Location: North Highlands. California Posts: 449	tac wiring question I would like to wire in my tac .I didnt see it on the wiring diagrams the are posted. Can some one tell me the ins and outs on wiring the tac. __________________ 67 short step 71 Custom

03-16-2012, 08:28 PM	#2
jjtackleberry Registered User Join Date: Feb 2011 Location: kansas Posts: 306	Re: tac wiring question DittoPosted via Mobile Device __________________ '71 Chevy LWB all OG '86 Chevy LWB all OG It's all a matter of perception

03-16-2012, 11:59 PM	#3
treveiger Senior Member Join Date: Jul 2010 Location: South Dakota Posts: 4,093	Re: tac wiring question Same here lol Posted via Mobile Device __________________ 1969 Chevy c20(Miss Hackjob)

03-17-2012, 10:16 AM	#4
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	Re: tac wiring question IIRC it a single wire that runs through a specific hole in the fire wall. s/t __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe.

03-17-2012, 10:44 AM	#5
bmfm64 Registered User Join Date: May 2011 Location: Covington, Wa Posts: 5,240	Re: tac wiring question It's a two wire set up. One goes to a switched spot in the fuse panel and the other goes out to the distributor or coil depending on points or hei dist. I also ran a ground wire from the stud on the back to the dash. Try searching more, this is were I found how to wire mine. If nothing else you can buy a repro harness that's plug and plug from any of the big suppliers.

03-17-2012, 12:32 PM	#6
MrSchaeferPants Registered User Join Date: Feb 2012 Location: JBLM, WA Posts: 153	Re: tac wiring question 3 or 4 wire depending on your tachometer. Probably a White/Red/Black/Green setup, on a lot of aftermarket tachs, the 4th being white, for a lighted tach, if applicable. Red -Switched 12v from panel/block/wherever. Black - Ground Green - Dist-Hei-Coil hook up. (Labled 'Tach' on most Hei's, not sure about a coil) White- Lights, splice in junction with dash lighting past the dimmer Not sure if you have a general aftermarket tach, someplace there's settings for 4,6,8 cyl that has to be adjusted. __________________ 68 GMC C2500 - 305 V6 - 4spd

03-17-2012, 01:28 PM	#7
bmfm64 Registered User Join Date: May 2011 Location: Covington, Wa Posts: 5,240	Re: tac wiring question Good call, are you trying to wire in a factory tach or aftermarket tach?

03-17-2012, 01:45 PM	#8
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,862	Re: tac wiring question Factory or aftermarket/points or HEI? __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

03-17-2012, 02:13 PM	#9
jjtackleberry Registered User Join Date: Feb 2011 Location: kansas Posts: 306	Re: tac wiring question Factory points Posted via Mobile Device __________________ '71 Chevy LWB all OG '86 Chevy LWB all OG It's all a matter of perception

03-17-2012, 02:22 PM	#10
MARIOS68PANEL Active Member Join Date: Mar 2005 Location: North Highlands. California Posts: 449	Re: tac wiring question Thanks all. Got it wired and it working fine . Stock tac - HEI dizzy- two wires. one to fuze block ond to dist cap = perfect __________________ 67 short step 71 Custom



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