Tach test
Racer
Joined: Jun 2005
Posts: 460
Likes: 0
From: Point Pleasant NJ
Originally Posted by WP23N
is there a test i can do to determine whether the tach is bad
or something is amiss in my wiring?
or something is amiss in my wiring?
Pro
Joined: Oct 2005
Posts: 581
Likes: 0
From: Boynton Beach Florida
most of the time its the circuit board behind the tach, its an easy replacement. the card is about $60 from most catalogs. try ECKLERS.. if your handy and have a tach and dwell remove the tach ,there are 3 contacts behind the tach, one is 12volts.one is a ground and the other is the tach signal..hook up the dwell meter if it works its probably the circuit board
Thread Starter
Drifting
Joined: Nov 2005
Posts: 1,795
Likes: 1
Originally Posted by palazzopl
most of the time its the circuit board behind the tach, its an easy replacement. the card is about $60 from most catalogs. try ECKLERS.. if your handy and have a tach and dwell remove the tach ,there are 3 contacts behind the tach, one is 12volts.one is a ground and the other is the tach signal..hook up the dwell meter if it works its probably the circuit board
exactly what i was looking for, i hate throwing parts at something.
would rather test and determine first.
thanks again
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
Originally Posted by palazzopl
... there are 3 contacts behind the tach, one is 12volts.one is a ground and the other is the tach signal..hook up the dwell meter if it works its probably the circuit board
Pro
Joined: Apr 2005
Posts: 603
Likes: 2
From: Illinois, USA
Originally Posted by WP23N
is there a test i can do to determine whether the tach is bad
or something is amiss in my wiring?
or something is amiss in my wiring?
Check this first:
1. Make sure you don't have any blown fuses -- the tach needs power
2. Check to make sure all the connections are tight and secure (some of them look fine, but you may want to pull and reseat them to be sure and remove any oxidation)
3. Bypass the filter that is inline right near the tach. it's a round barrel looking thing screwed to the intake (if it's stock).
If all that fails, then it is probably the board, and since I have done a replacement of that, it's a day project to get the dashboard apart to get at the board (it's mounted to the back of the guage) and reassemble. In my case, the replacement board was crap, too -- so I had to fix all the solder connections on the board.
One more thing, the board will often need to be "tweaked" to have it read right -- there is a adjustment pot on the board.
Compared to the other things I ended up fixing, this one wasn't that expensive to fix -- but it was certainly laborious. I also replaced all the lamps in the dash at the same time -- figured why go back in a month for a burned out bulb.
Brian.
Thread Starter
Drifting
Joined: Nov 2005
Posts: 1,795
Likes: 1
OK here is what mine is doing,
if i tap on the dash in front of the Tach repeatedly the needle will move
up to above the "0" as soon as i energize the ignition it drops all the way
to the bottom, when i shut it off the needle come back up ever so slightly to about 1/4 inch below the "0"
ideas?
if i tap on the dash in front of the Tach repeatedly the needle will move
up to above the "0" as soon as i energize the ignition it drops all the way
to the bottom, when i shut it off the needle come back up ever so slightly to about 1/4 inch below the "0"
ideas?
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Racer
Joined: Jul 2005
Posts: 499
Likes: 1
From: Winnipeg Manitoba
If the tach is working, but has no signal input, then it will drop to 0 and stay there.
Its possble to modify an low voltage A.C. Adapter into a tach tester by removing the filter cap.
A full wave rectified A.C. Signal should result in a tach reading of 1800 RPM
Its possble to modify an low voltage A.C. Adapter into a tach tester by removing the filter cap.
A full wave rectified A.C. Signal should result in a tach reading of 1800 RPM
