I just got a new tach and im trying to hook it up but Im having a problem. I know it is supposed to go into the blue wire on the engine. When I plug it in at the blue dot it works fine, but I dont want the tach wire streched across the whole engine like that. So I attached it to the same blue wire but just farther away from the engine at the red dot. But when I do this the tach goes all the way up to 4000 rpm and im not even giving it the gas. Any ideas why this is happening?

 

the blue wire goes also to the of the stock tach plugs. Even if its the auto version

 

I dont have a stock tach

 

The wires still is in the back of the tach, if you wanted to add a cluster with a tach its all plug in play.

 

or pull apart your dash hood
unhook your wiring,
and its in the left big plug, same blue wire.
that's what i did for my 91 ef
works perfect
even the shift light works
hope this helps

 

Maybe my car is different but the tach wire isn't in that plug with the red dot. It's in the square plug with the soft plastic/vinyl dust covering. I thought the wire was green w/yellow stripe BUT I'd have to check. Then again, maybe the dude that had the car before me and did a swap jacked all the wiring up.

Anyway, you know you used the wrong wire if the tach jumps to 4K without the engine running. I've been trying to locate a wiring diagram for the inside/cabin wiring harness so if I do, I will PM you with the wire you can use under the dash. This will save you running a wire all the way from the engine bay.

If anyone has a wiring diagram/book for the cabin harness on a 90 civic hb, please let me know.

 

Thanks everyone for your help. I hope I can get it working.


Modified by E.F.Honda at 2:03 PM 4/24/2008