Vacume Guage question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

farside847 · 03-20-2006, 12:20 PM

Got a new Tach and Vac kit and installed it over the weekend (thanks PICKMUP!)

Im sure it was set up correctely, but Fedex must have smacked it at some
point because the vac guage was pegged at 30 without any vaccume. With
vaccume it went further to the right. So I bent it back untill it made sence
to me. Now, at warm idle the guage says 18. It will go up to 25 coasting
downhill in gear, and drop to 8 going up hill. 0 when I floor it

- Does this
sound right?

Also, my new tach workes great, but when I turn on my blinker the needle
jumps with every blink. Is this normal? Or did I do something stupid?

Thanks!

67chevemall · 03-20-2006, 01:16 PM

sounds like a blinker wire is shorting with the tack or your wires are crossed.
Did you rewire it from a 3 gauge cluster to a 7 gauge?

farside847 · 03-20-2006, 01:46 PM

No, it had a guage cluster, but no tach or vac so they were added.

The tach works fine, the whole cluster works fine, but when I turn on my
headlights the tach jumps up for a sec then is fine. If I turn on my blinker
the tach will jump a second every time it blinks.....

67chevemall · 03-20-2006, 02:30 PM

where did you ground the tach?

farside847 · 03-20-2006, 02:46 PM

Quote:

Originally Posted by 67chevemall

where did you ground the tach?

I didnt.

The tach had a wire harness with two wires, a red one that plugged into
the fuse box, and a brown one that went to the coil. I assumed the entire
cluster was grounded..... Am I wrong?

68/72parts · 03-20-2006, 03:18 PM

The tach should be grounded somehow with a wire or by the mounting surface! your vacum seems to about right as long as you have a faily stock cam etc.

67chevemall · 03-20-2006, 03:51 PM

your cluster might now be grounded to the dash...maybe from paint ect...
When strang things happed it is usally a ground....

03-20-2006, 12:20 PM	#1
farside847 Registered User Join Date: Feb 2005 Location: Bay Area, California Posts: 995	Vacume Guage question Got a new Tach and Vac kit and installed it over the weekend (thanks PICKMUP!) Im sure it was set up correctely, but Fedex must have smacked it at some point because the vac guage was pegged at 30 without any vaccume. With vaccume it went further to the right. So I bent it back untill it made sence to me. Now, at warm idle the guage says 18. It will go up to 25 coasting downhill in gear, and drop to 8 going up hill. 0 when I floor it - Does this sound right? Also, my new tach workes great, but when I turn on my blinker the needle jumps with every blink. Is this normal? Or did I do something stupid? Thanks! __________________ 1971 Chevy C10 Shortbed Stepside, 307v8 3-on-the-tree

03-20-2006, 01:16 PM	#2
67chevemall Registered User Join Date: Apr 2003 Location: NB Posts: 3,367	Re: Vacume Guage question sounds like a blinker wire is shorting with the tack or your wires are crossed. Did you rewire it from a 3 gauge cluster to a 7 gauge? __________________ 1968 Chevy C10 307 3ott fleetside 1967 Chevy C/10 V8, 3spd, fleetside lwb.Sold 1967 Chev C/10 step, 383, M21. SOLD

03-20-2006, 01:46 PM	#3
farside847 Registered User Join Date: Feb 2005 Location: Bay Area, California Posts: 995	Re: Vacume Guage question No, it had a guage cluster, but no tach or vac so they were added. The tach works fine, the whole cluster works fine, but when I turn on my headlights the tach jumps up for a sec then is fine. If I turn on my blinker the tach will jump a second every time it blinks..... __________________ 1971 Chevy C10 Shortbed Stepside, 307v8 3-on-the-tree

03-20-2006, 02:30 PM	#4
67chevemall Registered User Join Date: Apr 2003 Location: NB Posts: 3,367	Re: Vacume Guage question where did you ground the tach? __________________ 1968 Chevy C10 307 3ott fleetside 1967 Chevy C/10 V8, 3spd, fleetside lwb.Sold 1967 Chev C/10 step, 383, M21. SOLD

03-20-2006, 03:18 PM	#6
68/72parts Registered User Join Date: Jan 2006 Location: Chilliwack B.C Posts: 59	Re: Vacume Guage question The tach should be grounded somehow with a wire or by the mounting surface! your vacum seems to about right as long as you have a faily stock cam etc.

03-20-2006, 03:51 PM	#7
67chevemall Registered User Join Date: Apr 2003 Location: NB Posts: 3,367	Re: Vacume Guage question your cluster might now be grounded to the dash...maybe from paint ect... When strang things happed it is usally a ground.... __________________ 1968 Chevy C10 307 3ott fleetside 1967 Chevy C/10 V8, 3spd, fleetside lwb.Sold 1967 Chev C/10 step, 383, M21. SOLD



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.