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View Full Version : Couldnt find a tach signal wire



TSimpler
11-13-2004, 17:34
Went to the dyno today. It is a dyno jet and we couldnt find a tach signal wire. I was only able to get Horsepower, no torque. :mad: The HP was at 378, very cool. I really want to know the torque. Highest HP of the day by 6 horse. Thats right just by 6, 3 rice grinders and 2 mustanges. I had braging rights for power and for blowing open the door of the shop

Does anyone know the location of a tach signal wire? It is very important for the dynojet. :confused:

Thanks
Trent

More Power
11-14-2004, 14:03
CKP - Crankshaft Position Sensor connector pin-C DK BLU/WHT wire

ECM Connector C1 - pin-12 LT BLU/WHT wire (CKP Sensor Signal)

ECM Connector C2 - pin-10 WHT wire (Engine Speed Signal)

MP

TSimpler
11-14-2004, 14:10
Can you give me locations of these? Please?

Are they on the computers or some place else?

Thanks
Trent

More Power
11-14-2004, 15:14
There are two long skinny electrical connectors that attach to the rear facing side of the Engine Control Module (computer). These are ECM C1 & C2.

I'd go for the "ECM Connector C2 - pin-10 WHT wire (Engine Speed Signal)"

Disconnect the negative battery terminal from each battery.

The ECM connectors are held in place by a single 8mm hex-head bolt. Loosen that bolt, and it'll automatically back-out the connector pair out of the ECM. Each connector is identified with pin numbers, but looking for a white wire on pin-10 shouldn't take all that long.

I installed and removed that connector pair several times during the buildup of our Project truck, and didn't experience any difficulty. Just be careful and don't force things.

Once you identify that wire, connect a pigtail lead to the white wire, and secure the connection in ways that will prevent future corrosion in the wiring and to prevent a shorted electrical connection, now or in the future. Find someone who is comfortable working on the vehicle wiring if you're in doubt.

MP

Kennedy
11-18-2004, 06:32
This wire runs to the instrument cluster to drive your tachometer. It reads approx 22hz at idle IIRC. You can get it at the cluster too like the remote start guys do.

Now the thing is, can the dyno read the low current pulsed signal???

Both of my Dmax trucks have a shunt run up to the electrical center for quick and simple dyno hookup...

TSimpler
11-18-2004, 09:50
"Both of my Dmax trucks have a shunt run up to the electrical center for quick and simple dyno hookup..."

Kennedy,

Please explain how you did this, I don't think the dyno will read a low current.

Thanks
Trent

Kennedy
11-19-2004, 06:28
It may not be able to read it. Most use the optic tach and reflective tape. My Superflow can read about anything that pulses consistently. I can easily alter the "pulses per rev" to suit the signal source.

I 've been splitting the tach wire, and splicing in using a dielectric filled 3m UR-100? connector. This is the kind that the phone company uses, and has 3 wires inserted parallel to each other then the tap is crimped down...