Stewart Warner tach wiring

[karterfred88]

If you remove the tach from the dash you can look inside the can thru the lamp hole. If the unit has been modified, you should see some empty space and a circuit board. Otherwise, you will see the tach mechanism that essentially fills the can. You will need the rectangular sender for that 765 tachometer. I have an NOS 1555474 sender but I'm heading to Warwick on Sunday. You should be able to find one from US Stude vendors.

Tim-the link I posted to SI is stubborn, I think their server need a restart or update, but if you go direct to SI, just enter "sender" without year make or model you will see the replacement unit-but it doesn't have the same part number. It is completely assembled with the correct wiring and should work-no round can needed.

[tim333]

Thanks Fred, ordered it.

[tim333]

WCP, NO WIRES were attached to the tach when I got the car except one from the right side terminal to the coil.

[tim333]

Instructions in post 16 call for 18 and 22 gauge wire. Ok to use 16gauge?

[tim333]

I received the sender today from SI which got it from Myer's. It has 4 wires; blue, brown, yellow and green. Instructions say blue to dist side of coil, brown to yellow or brass terminal of tach (says one terminal is brass, the other steel or white. They look the same to me), yellow to power source and green to ground. Unlike any diagrams in this thread. I guess I'll wait till Jon Myer gets back from Warwick and ask him unless anyone can chime in.

[karterfred88]

Tim
Looking at the back the left terminal is brass per your photo. However, I would talk to Jon, as there is no reference to the right terminal, just the ground. I did see one diagram that has the right terminal jumped to the ground terminal but I wouldn't chance that, The rest makes sense just no lead to the right terminal in the instructions you wrote.

[tim333]

Thanks Bill, let me know when you reach Jon, I'll do the same. My cell 678 773 5764.

[karterfred88]

I'm waiting for Jon to get back from New England too. Here's the way I think the tach should be wired with his instructions, but I want to make sure so that I don't burn up the new sender.

Bill L.
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I think-the two wires at the Tach are reversed, looking at your photo of the backside, the left one is brass, the right one steel. Since yellow is replaced by brown and all the diagrams have yellow on the left terminal ( all the drawings are as you would see it in the car from the backside, including the mount bracket showing on some). You need to explain to Jon that you have no trace of the original sender or it's wires, only your red power lead. I'm sure he will be able to supply a drawing that will make it work.

[tim333]

I talked to Jon Myer this morning. The brass terminal in indeed where the power source goes, the instructions with the rectangular sender are correct. The lone terminal at the bottom is a ground connection.

[56GH]

I talked to Jon Myer this morning. The brass terminal in indeed where the power source goes, the instructions with the rectangular sender are correct. The lone terminal at the bottom is a ground connection.

Thanks, Tim. I was also waiting for a reply. I'll wire the sending unit accordingly as soon as our "early summer" softens up a bit in Florida. It's 99 F today! More rain please!




Bill L.

Wired according to instructions. Still no tach!


Post note:

Turned out that the Myers sending unit was bad. Jon sent me another at no charge and it's been working fine. I decided to wire it in with a terminal strip. The sending unit from Myer is untouched as far as wire length is concerned and I mounted it to the inside upper firewall. The wiring from the terminal strip to the respective terminals of the car is "permanent." That way, if a sending unit goes bad again, it's easier to wire it in.

[tim333]

I just tested the head with a little battery per Jons tip and it works. I'll put in the sender in a day or so.

[tim333]

Humid here too. Sweated my ass just testing the tachometer and installing new kickpads.

[tim333]

I installed the rectangular sender today, tach works fine. Thanks guys.

[56GH]

The tachometer problem in my 1962 GT Hawk is solved!! Jon Myer was gracious enough to furnish me with another one of his tach sending units after many e-mails and discussions about the wiring procedure on the first unit. Turns out, the unit PCB was bad. I installed the second one he sent me today and it works great! Thanks to Jim at S-I and Jon for taking care of me!

Bill L.