not cranking after tach - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**PowerdbyChevy79** · 02-17-2017, 01:13 PM

hey guys..having an issue.. working on 70 that had idiot lights.. I installed a factory full gauge set up repined the harness.. all that is good.. now it wont start.. getting fire at the dist.. new rotor.module...it just cranks over no spark..so I go and disconnect the tach wire from the dist.. and bam it starts right up.. help me out guys..never had this issue before..

davepl · 02-17-2017, 01:18 PM

Must be a ground or power path through the tach lead, so I'm guessing that line is pinned wrong or somehow shorted?

Check continuity from your distributor to the back of the tach, and if that's good, check it to ground and power too (which it shouldn't be a direct path to).

*randy500* · 02-17-2017, 01:37 PM

Tach wire hooked up to positive instead of negative side of coil.
Tach and distributor wires should be connected to negative on coil.

**PowerdbyChevy79** · 02-17-2017, 03:42 PM

I have the wire connected to the negative side of the dist..

02-17-2017, 01:13 PM	#1
PowerdbyChevy79 Senior Member Join Date: Apr 2013 Location: Houston,Tx Posts: 743	not cranking after tach hey guys..having an issue.. working on 70 that had idiot lights.. I installed a factory full gauge set up repined the harness.. all that is good.. now it wont start.. getting fire at the dist.. new rotor.module...it just cranks over no spark..so I go and disconnect the tach wire from the dist.. and bam it starts right up.. help me out guys..never had this issue before.. __________________ 1966 C10 "Mary" 1972 C10 Cheyenne "Betty" https://67-72chevytrucks.com/vboard/...d.php?t=847364 1976 C35 Sierra Grande "Mr. Harvey" 1979 C10 Silverado "The BIG TEN" https://67-72chevytrucks.com/vboard/...d.php?t=841339 1982 C10 Silverado "Lucy" C10 Club Texas -HMIC

02-17-2017, 01:18 PM	#2
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: not cranking after tach Must be a ground or power path through the tach lead, so I'm guessing that line is pinned wrong or somehow shorted? Check continuity from your distributor to the back of the tach, and if that's good, check it to ground and power too (which it shouldn't be a direct path to). __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

02-17-2017, 01:37 PM	#3
randy500 Account Suspended Join Date: Jul 2016 Location: Tacoma, WA Posts: 6,873	Re: not cranking after tach Tach wire hooked up to positive instead of negative side of coil. Tach and distributor wires should be connected to negative on coil.

02-17-2017, 03:42 PM	#4
PowerdbyChevy79 Senior Member Join Date: Apr 2013 Location: Houston,Tx Posts: 743	Re: not cranking after tach I have the wire connected to the negative side of the dist.. __________________ 1966 C10 "Mary" 1972 C10 Cheyenne "Betty" https://67-72chevytrucks.com/vboard/...d.php?t=847364 1976 C35 Sierra Grande "Mr. Harvey" 1979 C10 Silverado "The BIG TEN" https://67-72chevytrucks.com/vboard/...d.php?t=841339 1982 C10 Silverado "Lucy" C10 Club Texas -HMIC



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