I bought an Autometer tach to install in my 96 F250 with 351. Instructions say to wire it to a tach signal coming from the electronic ignition. Anyone know where this wire is? Or if there is another place to hook it? Also, where is the best place to install a trans. temp sensor without pulling the pan?

Thanks.

 

The ignition wire will go to your coils' ground. I routed mine through firewall an stuck the wire in the ground side of plug, if you do it right itll stay forever lol mine has.

 

tach wire goes to distributer or neg side of coil , temp sensor should go into the side of trans pan , the stock pan may not be thick enough to drill & tap , so you might need to weld a bung on it ....Lew

 

Like mentioned, look at the coil, there is a large two prong plug. One is the neg(if I recall it's brown?). Tap into this wire. With truck running, have someone watch tach as you touch your green tach wire to each wire. When it works, that's the one.

 

You do not have to go into the Ignition system in the engine compartment and through the firewall to get to the tach wire.

The tach wire is located on the back of your Instrument Cluster.
It is a white wire with a pink stripe, #648 (W/PK) on pin #9 of the Black Plug and is unused if you do not have a stock tach.

 

That tip about a tach signal from the back of the IC is great info.

I've got my cluster out to replace the clear bezel (on my '97 F350) and am wiring in an aftermarket tach while I'm at it, but the closest match is a white wire with a purple stripe. Is that the one I should try? It's in the small black center connector.

Also, to test it, will it irritate the computer or other circuits to start the truck with the IC unplugged?

Thanks...Paul

 

It should be a W/PK wire on pin #9 of C250.

 

I get the W/PK lingo, but the rest is greek to me. Is there a wiring reference thread that explains the pin/connector references?

 

Yes there is:


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Solid info...thanks!

Any thoughts on the question about starting the truck with the IC completely removed?

 

As long as the fuel selector switch is not unplugged I do not know any reason that it would not start and run. If you try to drive it the transmission will shift hard if it is an automatic if the center PSOM plug is unplugged. Also it will not charge with the cluster unplugged.

 

On the E4od the is a test port on the drivers side right above the pan. That is a great place to get trans temp, I have mine there and it work well

Jim