I am trying to hook up a VTAC brand tachometer. I have never used one and don’t know exactly how it is suppose to work. It activates, but I don’t think it is reading any RPM’s. It only shows 0000’s and other standard information, then after about a few minutes it goes blank. Note that it will bring up the display I described by pushing the recall and light buttons, and will also display on its own when the motor starts. I have dual MSD series 6 ignitions, one runs with a crank trigger and the other on the distributor. I have the black wire of the VTAC to ground and the white wire is run to the white wires coming from the MSD’s tachometer trigger. I have read that the VTAC needs to be grounded to the engine block, but I have an aluminum motor and have it grounded to the frame. Any ideas? Thanks for any help.
VTAC Tachometer with dual MSD, how to wire?
- Thread starter 4sracn
- Start date
Morgan
New Member
Wiring r Fun
If somehow I got the right VTAC model.
Once the motor stops, the VTAC will display 0000. Press and hold the RECALL button for 3 seconds, on the top line you will see MAX rpm + BEST lap number. The second line will show lap number then HI-LOW-HI-LOW rpm for the indicated lap. Press and hold the RECALL for 1 second. The second line will now show lap number followed by the high and low rpm results. As the RECALL button is pressed the results for laps 1-100 will be shown. The results will be kept in memory until the motor is re-started or the VTAC is reset.
After 1 minute, the display will go into SLEEP mode to conserve battery life. Push RECALL once to wake the VTAC up from sleep mode and return to the results. To turn the back light on press and hold the light button. The light will stay on for 30 sec after you have finished viewing the recorded laps.
The VTAC is pre-set for 8 Cylinder Magneto
To switch to a non-magneto system, or less than 8 cylinders, follow the SETUP instructions in the VTAC OPERATION INSTRUCTIONS
a. VERTEX INTERNAL COIL
· Attach White wire to positive post on magneto using connector marked Vertex.
· Attach Black wire to cylinder head on ENGINE BLOCK.
b. VERTEX EXTERNAL COIL OR MALLORY MAGNETO
· Attach White wire to positive post on Coil using connector marked Sprint Mag.
· Mallory must have orange wire as positive.
· Attach Black wire to cylinder head on ENGINE BLOCK.
c. MSD PRO MAG
· Do not use connectors marked Vertex or Sprint Mag.
· Attach White wire of cable to positive on kill switch.
· Attach Black wire to cylinder head on ENGINE BLOCK.
d. MSD 6A
· Attach White wire to distributor Purple wire
· Attach Black wire to cylinder head on ENGINE BLOCK.
e. GM HEI
· Attach White wire to TACH terminal on HEI.
· Attach Black wire to cylinder head on ENGINE BLOCK.
f. MINI SPRINT
· Do not use connectors marked Vertex or Sprint Mag.
· Connect to factory tach wire
I see you have power to it just make sure it has a good ground close to the tach they get really pissy sometimes if the ground is weak or far
away.
If that don't help post and yell at me, call me names and I will try to think of something else. Or if you wanna go insane here is every setup ever for all the MSD box's. Searching through 4000 setups to find what you need is fun. Start on page 40 I think.
http://www.msdignition.com/pdf/WireDiagrams/WDTN.PDF
And
http://psinnovations.net/installation.doc Vtac install doc
Morgan your friendly Dixon Crew......Ummmm what do I do again?
If somehow I got the right VTAC model.
Once the motor stops, the VTAC will display 0000. Press and hold the RECALL button for 3 seconds, on the top line you will see MAX rpm + BEST lap number. The second line will show lap number then HI-LOW-HI-LOW rpm for the indicated lap. Press and hold the RECALL for 1 second. The second line will now show lap number followed by the high and low rpm results. As the RECALL button is pressed the results for laps 1-100 will be shown. The results will be kept in memory until the motor is re-started or the VTAC is reset.
After 1 minute, the display will go into SLEEP mode to conserve battery life. Push RECALL once to wake the VTAC up from sleep mode and return to the results. To turn the back light on press and hold the light button. The light will stay on for 30 sec after you have finished viewing the recorded laps.
The VTAC is pre-set for 8 Cylinder Magneto
To switch to a non-magneto system, or less than 8 cylinders, follow the SETUP instructions in the VTAC OPERATION INSTRUCTIONS
a. VERTEX INTERNAL COIL
· Attach White wire to positive post on magneto using connector marked Vertex.
· Attach Black wire to cylinder head on ENGINE BLOCK.
b. VERTEX EXTERNAL COIL OR MALLORY MAGNETO
· Attach White wire to positive post on Coil using connector marked Sprint Mag.
· Mallory must have orange wire as positive.
· Attach Black wire to cylinder head on ENGINE BLOCK.
c. MSD PRO MAG
· Do not use connectors marked Vertex or Sprint Mag.
· Attach White wire of cable to positive on kill switch.
· Attach Black wire to cylinder head on ENGINE BLOCK.
d. MSD 6A
· Attach White wire to distributor Purple wire
· Attach Black wire to cylinder head on ENGINE BLOCK.
e. GM HEI
· Attach White wire to TACH terminal on HEI.
· Attach Black wire to cylinder head on ENGINE BLOCK.
f. MINI SPRINT
· Do not use connectors marked Vertex or Sprint Mag.
· Connect to factory tach wire
I see you have power to it just make sure it has a good ground close to the tach they get really pissy sometimes if the ground is weak or far
away.
If that don't help post and yell at me, call me names and I will try to think of something else. Or if you wanna go insane here is every setup ever for all the MSD box's. Searching through 4000 setups to find what you need is fun. Start on page 40 I think.
http://www.msdignition.com/pdf/WireDiagrams/WDTN.PDF
And
http://psinnovations.net/installation.doc Vtac install doc
Morgan your friendly Dixon Crew......Ummmm what do I do again?