Ok, here goes... I installed a Superlift Truspeed on my SD a couple of weeks ago. After getting it all adjusted a nice and neat, it worked great, for about a week that is. One day i start up the truck and my speedo jumps up to 70-80 mph, with the truck in park. I troubleshot it but ended up just jumping out the wires from the ABS unit, really just wiring it up back to the stock setup. The speedo then worked again and didn't jump up when i started the truck.

I talked to Superlift tech support and they told me it was probably a bad truspeed if it works ok stock. They sent me a new one and i tryed to swap it out last night. With the new truspeed installed it did the same thing! I tryed reseting it with no luck. The speedo won't always jump up when i turn the key to run but it always does it after i start the engine, no matter what setting i'm in 1 or 2... I jumped the wires from the ABS unit and sure enough the speedo worked normally, but it's still off with the big tires on.

So i don't know what's going on, i'm calling superlift back tomorrow. Anyone ever have a similar problem with the speedo

Thanks

Nelson

 

I installed one a while back.. fun to install right? Have you checked the basic connections for the truspeed? Is it propperly grounded.. and are you using the fuse they suggested for the power source? And then are your green and yellow wires soldered on good and shrink wrapped? Make sure none of it is exposed. I know thats just the basic stuff but gotta start somewhere....

 

I finally fixed this problem last weekend. I dug my way back to the abs module and resoldered the yellow and green wires. I made sure I sealed it all up real nice cuz it seemed to be wet in the wire loom. It's been workin fine so far. At least I got a second truspeed for free outta this mess...:-)

Nelson