440 source Street distributor

[Houle #382]

Issue solved

 

[pnora]

What dash do you have?

 

[pnora]

The tach is not in the dash it's a Sun Super tach 2 mounted on the steering column and when I have the Mopar performance distributor in the tach works perfectly

The ones I have used also had a 12 volt keyed feed. If yours is just 3 wires cut the wire from the coil and splice the red going to the coil and yellow to the tachometer.

 

[pnora]

Where on the tach do you put the yellow wire? I know the red goes to the negative side of the coil and black is ground but there is nowhere to hook it to the tach. The three wires coming out of the tach are attached to a circuit board

The yellow goes to the tachometer. You cut the wire in two that now goes to the coil from the tachometer. Then splice yellow on the tach side of the wire and red on the coil side of the wire.

 

[Geoff 2]

Congrats on using HEI, a great ign system.

Three wires out of the tach suggest:
- one wire for 12v + [ most likely red wire ]
- one wire to coil neg for triggering
- one wire for the internal lamp
Case is the grd connection. You should call Sun to verify wire colours etc.
Some tachs require a filter/adaptor to work with HEI. One of the MSD adaptors will likely work, contact MSD for more info.

 

[pnora]

I re read you text I have 3 wires out the back of the tach, black is ground red is to the negative side of the coil and green to the lights

Makes no sense. The tachometer should have a keyed 12 volt power source. Just about all Sun tachs are wired like this.
1-Red 12 volt keyed power.
2-Black ground
3-Green negative side of coil.
4-White lighting circuit.
Unless you have a very old tachometer with a box that acts as a driver interface.

 

[pnora]

Yes it's an old

Yes it's an older Sun tach 2 with only 3 wires. Red to negative black to ground and green to lights

So you do have an interface box.

 

[pnora]

Best to post some pics of what you have going on. Makes no sense to me.

 

[pnora]

No there is no interface box. I got the tach from a buddy and it was just the tach and 3 wires

Just google tach wiring. Red does not go to the coil its keyed 12 volts.. Black is ground. Green is to the negative side of the coil. White is lights. Maybe if you hook it up right it might work correctly.

 

[pnora]

MY TACH DOES NOT HAVE 4 WIRES it only has 3 as I have stated many times only 3

AND READ WHAT I HAVE SAID MANY TIMES IT SHOULD HAVE 4. You have a screwed up tach then. It defies all logic. Just google sun tach wiring. Use the 3 wires. red 12 volt keyed. Green tach negative, Black ground.

 

[pnora]

I have had this tach apart there never was a 4th wire, this tach is a good 40 years old and works perfectly with my Mopar performance distributor

OK you win.

 

[pnora]

Explain how your tachometer works without a 12 volt keyed power supply.

 

[Geoff 2]

There are two types of triggering methods for Tachs. Voltage triggered, the most common, connects to the coil - ve terminal.
Current triggered connect between the ign sw & coil positive terminal.