Speedo Issues after swap

[bigblockford79]

Just finished my 5.0 HO swap into a 95 ranger 2WD. This is the first year for the electric speedo.

Here is my issue -

The truck had the 2.3 in it when I bought it, I pulled and sold the 2.3L and sent the ECM with the engine. I also hooked the guy up with all wiring that was attached to the engine. This even included the loom that ran down to the transmission, which also contains the speedo wires. I assumed that the speedo was still cable driven like the one in my 93 is, of course I was way wrong. I have since tracked down the speedo sending unit and the wiring harness from the sender. I have also found the wires were they come into the bulkhead connector, but when I spin the sender in my drill with the key in the on position I get nothing on the speedo.

I then went to the local u-pull-it yard to hunt down a similar truck to trace the wires and see where they went. The wires (2) come from the trans to the main engine harness and they "y" off with 1 leg going to the bulkhead connector and the other to the ECM plug.

My major question is this - Does the speedo sender signal HAVE to run to the ECM for the speedo to work? Or Should I be able to get it to work without the ECM? I am thinking since the wires both split and one set seems to run directly to the dash/speedo I should be good to go. (In Theory, but we all know how those work).

Thanks in advance for the help.

I am ready to drive the truck but don't want to use GPS on my phone to monitor my speed. Not to mention my insurance company is going to wonder whats up if the mileage on the odometer never changes.

 

[--weezl--]

i seem to remember that the speedo module in the dash, is paired with the ecm, to eliminate people being able to swap gauge clusters out, to commit odo fraud... i wouldn't have figured that the speedo would be effected too, but that would make sense, thinking about it now

even a replacement ECM, i don't think will bring your speedo back, it's got to be the one that your speedo came with

sorry for the bad news

 

[modelageek]

 

[bigblockford79]

No engine harness on my truck, just a carb and MSD. I did figure out my speedo and it works now. I ended up going right to the plugs on the gauge cluster and tracing the wire paths on the backside to figure out which wire did what.

Thanks for the help.