Hey guys,

I have a 1975 ford maverick 5L in my 1984 rx7. I have it running and stuff but i cannot seem to make the tachometer work. The duraspark 2 module has a green wire that is supposed to connect to coil negative green wire. I connect it and the car will run. When i disconnect it the car will no longer run. So as per the duraspark two diagram found at the bottom of this thread:

http://www.justanswer.com/jeep/3tnrj...along-new.html

The tach is supposed to connect to the coil neg also. So if i take the tach signal wire and splice it into the connected green ignition wire that connects the module to the coil -, the car wont run. So i have no idea how to make the tach work with this ignition system. Does anyone have any ideas?

Thanks

 

I hooked mine up closer to the module and sliced in the green wire. Worked for me just fine.

 

Im no expert by ANY means but I've got a green wire in my harness that goes to the dash. I have idiot lights but I've read that many options where pre wired. I think this may be for the tach on vehicles with gauges.

I might read up on this tonight. It would give you the cause of the issue but it might be a work around.

Just a thought. Maybe better thinkers will chime in at some point.

 

For clarification it is tied into my module. Not just a random wire going into the dash.

 

Sorry but im having a hard time understanding. The first post i understand, just when i splice the tach signal wire in to the green wire that connects the coil - to the green on the module it will not run. Disconnect and its fine. Dunno what i could be doing wrong.

 

I think the only thing a can I can suggest from my limited experience is to check and recheck the connection.

Once I tested my tach I soldered and heat wrapped my splice.

Make sure everything is shiny clean and has good contact. I'm glad I didn't run into any problems. I feel for you.

Have you tested resistance and continuity?

 

Is it a factory tach or aftermarket? Something may be grounding out.

 

Okay so i took the wire that connects directly into the back of the gauge cluster, cut it and ran a new wire- directly to the durapsark green connection. Spliced it in and the same thing happens, so i can know it is not the wires fault.

 

Do you have a multimeter?

 

I do, but i dont know that much about using it. I'm sure if there's a test to do i could figure it out though.

 

Sorry for the delay. I'm in a rush to get on the road to get to work for the week.


What I think you need to look for is your tach wire grounding out. If your wires and connections are sound then it more than likely is in your gauge cluster.

 

You are very sure that the connection here is made in the proper place? Make sure nothing is touching the wire or connection.

 

I checked on my truck before I left for the week yesterday. If you use the continuity setting on your multimeter, ground to the engine, the positive side should beep the negative(tach) side should not. I had it already disconnected.

This MIGHT tell you if it is your problem.

Hopefully someone else that knows more than I will correct me if I'm wrong.

Let me know what you find out.


(I just used the top of a.c. for groundbut did have to scratch it with the probe to get a good connection)

 

Hey,

So i went out there today to check. The wire that connects the tach to the car has been cut. I had made a new wire that comes out of the back of the gauge cluster connected to the tach wire spot and runs to the duraspark/coil connection and spliced it in. With it connected the car wont run. Any way you can explain the multimeter thing a little bit better? I dont fully understand.

I have no idea why it wont work, it seems like a simple 3 wire system :S.

Thanks

 

The multimeter: you should have some sort of continuity setting. Mine looks like a volume symbols. Its my first multi meter so I don't know if there are other symbols for other brands. Owners manuals will surely be available online through the manufacturers website. Just Google the model number and include manual in the search.

Ground (black) probe can go to any ground source. The negative battery cable, the block, alternator etc. I did find I had to scratch the surface of my alternator to get a good reading.

Positive (red) probe goes to the wire you want to test.

My multi meter gives an audible signal plus the ohm reading if there I'd continuity (meaning a complete circuit.)

Disconnect your horse shoe (the black housing that the wires from your duraspark fit into, pull the entire thing straight back, not the individual wires). Stick your probe down in there so it makes contact with the metal connector.

The 'batt+' side should beep (meaning the circuit is complete). The 'tach test' should not.

It's an easy enough test to do and the basis of finding short circuits. A skill to know for sure.

I do not know for certain that this test will show you your problem. Ive never experienced this problem before and what I'm thinking your problem is (tach grounding) is purely theoretical. I might be wrong but this is how I have it worked out in my mind. Reading about how your ignition coil and what the tach work might let you follow my line of thinking.


Please keep us posted.