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Old 07-27-2013, 03:53 PM   #1
mike88a
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Tach adaptor question

Ok so I have a 327 and am running a Mallory Unilite distributor and a promaster coil. I installed a tach and it doesn't work. I did some reading and figured out I needed the 29074 tach adaptor from Mallory. The problem is that I don't quite understand the instructions. I am hoping once again you guys can straighten me out!!! I attached the instructions. Where do I connect this thing? I get the switched 12v side, its the other wire. Does it go between the distributer and the coil? Or after the coil?

THANKS!!!
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File Type: pdf Mallory_Instructions_tach_adapter_29074.pdf (120.9 KB, 98 views)
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Old 07-27-2013, 08:54 PM   #2
haysonj
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Re: Tach adaptor question

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Originally Posted by mike88a View Post
Ok so I have a 327 and am running a Mallory Unilite distributor and a promaster coil. I installed a tach and it doesn't work. I did some reading and figured out I needed the 29074 tach adaptor from Mallory. The problem is that I don't quite understand the instructions. I am hoping once again you guys can straighten me out!!! I attached the instructions. Where do I connect this thing? I get the switched 12v side, its the other wire. Does it go between the distributer and the coil? Or after the coil?

THANKS!!!
I'm not much help but I bought the same one for my Edelbrock pro flow and have never got it to work
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Old 07-27-2013, 09:10 PM   #3
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Re: Tach adaptor question

Do you have HEI? I do, and when I installed my tach, I bought one of these and just spliced the wires to it and plugged it in to the side of the ignition and ran a power source back to the block.

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Old 07-28-2013, 12:36 AM   #4
mike88a
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Re: Tach adaptor question

No I am running a Mallory Unilite. I will just call Mallory Monday.
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Old 07-28-2013, 12:54 AM   #5
Zable49
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Re: Tach adaptor question

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Originally Posted by mike88a View Post
Ok so I have a 327 and am running a Mallory Unilite distributor and a promaster coil. I installed a tach and it doesn't work. I did some reading and figured out I needed the 29074 tach adaptor from Mallory. The problem is that I don't quite understand the instructions. I am hoping once again you guys can straighten me out!!! I attached the instructions. Where do I connect this thing? I get the switched 12v side, its the other wire. Does it go between the distributer and the coil? Or after the coil?

THANKS!!!

Honestly I am not sure why you would need a tach adapter. A tach just hooks up like this.
The green wire is the "tach" signal which also goes to the negative side of the coil. Brown wire goes to ground and red wire to ignition hot.
It shouldn't matter what kind of coil you have, and it shouldn't even touch your dizzy. Atleast thats my thinking of it. Hope it helps
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Old 07-28-2013, 01:04 AM   #6
mike88a
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Re: Tach adaptor question

Unfortunately with a unilite or a MSD or any electronic there is a possibility of needing some type of filter or adaptor. I wish it were that easy. Thanks though! At least I don't feel so bad now. I thought I would get hit right away with a bunch of guys saying oh you just do this or this.
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Old 07-28-2013, 01:13 AM   #7
Zable49
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Re: Tach adaptor question

Well d***, well when you find out please let us know.
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Old 07-28-2013, 01:47 AM   #8
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Re: Tach adaptor question

Well do!
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Old 07-30-2013, 05:41 PM   #9
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Re: Tach adaptor question

Well I am still at a loss. I talked to Mallory today and despite the fact that their website says that is exactly what the 29074 is for they say it will not help. But the guy said to hook it up to a switched hot and the other side between the distributor and the coil. Kind of frustrating to say the least. Hopefully I will get a chance to put it on and see for myself this weekend.
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Old 08-02-2013, 04:12 PM   #10
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Re: Tach adaptor question

Okay!!! Problem resolved.

I still have not hooked up the adaptor but I did check all of my connections and even sanded the area my ground was hooked up to so I was sure I was getting a good ground. Still same problem.

Soooo I connected the Tach Adaptor just using alligator clip jumpers. One side to the hot on the battery to simulate the switched hot. The other side to the negative side of the coil.

Despite the genius at Mallory insisting it would not have any affect on the Tach it solved the problem.

Now just for a little time to find a good spot to mount it and run the wires in a stealthy way!
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