Tic tock tack and MSD ?

[boneheadsGeTeX]

My trouble (this time) is tack. I have 70 gtx. Reswiring and gauges. Yesterday it was turn sign thanks for help got them working. Now I need to wire up tach. The car didn't come with tech I got a used one on ebay. I have MSD I put the board for MSD in the tach and I have new harness yearone. What I need to know 1 I can't find where the tach ties into harness. 2 serv book said it's a blue wire I can't find. But I have two big wires at end of harness but can't find anything about them in serv book (they have eyelets) I put a new engine harness also

 

[bigmanjbmopar]

I'm going to need pictures on this one if you are going to try to use the harness wiring, otherwise just run one wire to the msd box to the tach output follow the instructions on the msd box for connections.

 

[boneheadsGeTeX]

I was Thinkin I could just run a wire from MSD tach output over to back of tach but didn't realy know. That's what I'll do next thing. Them wires. They don't show up on my book but my books old grease stained pages gone anyways here is picture of them it almost end of harness

 

[bigmanjbmopar]

Here are your basic wiring diagrams now that I see its a 70 GTX lol I say basic because they are mostly generic but will give a good idea where each wire goes and where it is on the firewall block

http://www.mymopar.com/downloads/1970/70BelvedereGTXSatelliteRoad RunnerA.JPG

http://www.mymopar.com/downloads/1970/70BelvedereGTXSatelliteRoad RunnerB.JPG


Also here is a good link to the tic toc wiring, in your picture I don't see the grey wire with the square connector to the tach? Blue goes to 12vdc on the tach not sure what the green and the other connector is in your harness.

http://www.performancecargraphics.com/images/Catalog/Catalog3.pdf

 

[boneheadsGeTeX]

Ya Iv got the gray wire pluged on tach my book said it was to the clock ? The blue wire is the one to the tach ? Thanks

 

[bigmanjbmopar]

No blue is supposed to have 12vdc on it. Grey should go to the negative side of the coil in the factory harness. There is a grey from the fuse box to the clock for power. don't get them mixed up you will ruin the tach

 

[Hemirunner]

You'll need a tach adapter to get it to work.

 

[boneheadsGeTeX]

Tach adp ? Ok I see now it's right there in the MSD book. It said to try it first the. If it don't work get one. Bigmanmopar thanks for links. So tell me if righ in. The blue wires with the one eyelet it goes on the 12 volt pole. The other one ( gray wire) I'm not going to use it But run a wire from MSD box outlet. Will that work? If not then use the adp ? Am I right in my thankin?

 

[Car Nut]

You'll need a tach adapter to get it to work.

:yes: