SUN retro tach install??
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From: GA, USA
SUN retro tach install?? 05 H2 in a 55 Chev.
Tried to do a search.. got no responses.
Pin 10/ green plug has the tach output wired in. Checked for 5 vdc sq wave..none. [Per SUN tech dept.]
Have looked at the .tun file.. See a choice for 12vdc pullup being on or off. It's now on. Should it be "off"???
NE1 do this install??? NE problems?
TIA,
Tried to do a search.. got no responses.
Pin 10/ green plug has the tach output wired in. Checked for 5 vdc sq wave..none. [Per SUN tech dept.]
Have looked at the .tun file.. See a choice for 12vdc pullup being on or off. It's now on. Should it be "off"???
NE1 do this install??? NE problems?
TIA,
Check a couple of things. Is the tach in 4cyl mode? With the ls's square wave it reads as a 4cyl car does. Also on my 55 sedan with a 6.0 I had to place a resistor 1k ohm 1/2 watt connectd between the 12v switch and ground to the tach. Made my autometer work. Before the resistor the tach had no response. Go to radio shack they are less than 2 bucks for 5 of them. Hope either of these helped!!!
Joined: Sep 2004
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From: Downers Grove, IL
You could try with the pull up off in the tun file. However I would think it would be more likely to work with it enabled. That command takes the place of the external resistor to 12v trick. My factory el camino tach works without the pull up enabled so the sun tach should also work.
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From: GA, USA
No.. Check a couple of things. Is the tach in 4cyl mode? With the ls's square wave it reads as a 4cyl car does. Also on my 55 sedan with a 6.0 I had to place a resistor 1k ohm 1/2 watt connectd between the 12v switch and ground to the tach. Made my autometer work. Before the resistor the tach had no response. Go to radio shack they are less than 2 bucks for 5 of them. Hope either of these helped!!!
As for the sq wave signal.. My "test" was invalid... I tried to use a digital VOM meter
My EE bud quickly straightened me out on that!I guess I don't understand how/what a "pullup" is. EFILIVE .tun file has a yes/no choice,and I "understand" that 12v p/u is on the white wire pin 10.
More later!
Thanks!
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From: GA, USA
Update.. loaded the .tun with the 12v pullup off, still no tach reading.
This is w/ the cyl choice set at 4 cyl.
Using a digital VOM, set on a/c volts.. Got no volt output even near 5v. near .02-.03.
Have a scope coming... Will post the results.
In the meantime I am going to try a 10k resistor from the 12v switched stud, to the signal stud. Mite make the tach and/or the pcm scram. But, the famous "smoke test" is about to start!
More later!
This is w/ the cyl choice set at 4 cyl.
Using a digital VOM, set on a/c volts.. Got no volt output even near 5v. near .02-.03.
Have a scope coming... Will post the results.
In the meantime I am going to try a 10k resistor from the 12v switched stud, to the signal stud. Mite make the tach and/or the pcm scram. But, the famous "smoke test" is about to start!
More later!
Last edited by Old Geezer; Jun 8, 2011 at 10:48 AM.
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Thread Starter
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From: GA, USA
Update>>>> Added the 680ohm resistor across the power and signal posts on the tach. Set the cyl choice at 4...WORKS LIKE CHARM!
FWIW, never could figure out why the pcm pullup enable would not work...
Next test: Compare the tach reading w/ the rpm shown on the EFILIVE dash...
FWIW, never could figure out why the pcm pullup enable would not work...
Next test: Compare the tach reading w/ the rpm shown on the EFILIVE dash...
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