Hi all. I've been a long time reader of the forum, but this is my first post.

I know a few of you guys have installed Z1s in newer F-250 super dutys. I'm installing a Z1 in a 2005 F-250 diesel and am having a problem finding a feed that works. The gray/black wire at the radio harness does not work. The gray/black wire from pin 21 of the ABS module didn't work, and the gray/orange wire at the PCM shows speed pulses when moving slowly, but at road speeds it reads grossly high showing thousands of pulses every couple seconds, and the Z1 gives a Vss error message in the hardware info screen.

What wire are you guys using? I'm about to pull out my hair.

the one at the radio harness as indicated before. but your getting an error have you reset the unit and see what that gives you?

Yes, I did a level 3 reset. It still gives the error with it hooked to the Vss wire from the PCM. I don't remember the exact error, but it's something like "Vss gross error detected. Reset unit, check connections, and try again."

When I had it hooked to the gray/black from the radio harness, I never tried driving the truck. I just tried moving it 20 feet or so in the driveway and didn't get any pulses. Do you have to get up some speed before that wire works?

why not let it go around the block, cuz the one in the radio harness is what we all use i think. so give it a little to catch it.

Thanks for the info. I'll give it a try in the morning.

My installation knowledge is limited to the very few vehicles I have worked on but I did install a Z1 into my friends 2005 F250. His radio did not have a VSS wire at the wiring harness. So I could not use it. It did not exist.

I did pull off the gray/black wire off the abs module and it works perfectly. I don't remember the exact pin number but I could look it up if need be. 21 sounds right as long as it's gray/black.

And yes, you can't just go slow in your driveway to get pulses, you need to go around the block like tillithz said.

But I used the abs module, not the radio harness cause there wasn't one in my F250.

I ma going off of how my 05 f150 was, and the info Ive gotten from others about the 250. so if ducatiboy has a similar experience with THAT exact car, go with what he is saying about abs, but again you might want to try the easier route, and drive round the block to see first.

I ma going off of how my 05 f150 was, and the info Ive gotten from others about the 250. so if ducatiboy has a similar experience with THAT exact car, go with what he is saying about abs, but again you might want to try the easier route, and drive round the block to see first.

Oh absolutely try just going around the block... do that first. I'm not saying to yank what you have before you test it and just go with the ABS location. I only had to go with the ABS location cause my particular 2005 F250 did not even have the radio harness location. It's possible that different levels or models of the 05 F250 might have the VSS at the radio location, if so I would have tried that.

But the gray/black wire on the ABS location under the hood did work with my Z1. And it works really well. I did not have a gray/black wire behind the dash.

I know you said you tried the ABS location and you said it didn't work.

If you have the same gray/black vss wire behind the dash and at the ABS location... and both give you weird results, what are the possibilities that the ford circuit that produces this signal is working correctly. How well does the cruise control work, I think they generally take the speed off that signal.

Thanks for all the info guys. I'm heading over to try the radio harness and then the ABS if that doesn't work. I bet it will work once I drive down the block a little. When I tried the radio and the ABS, I just tested it in the driveway.

One thing I can say for certain is the gray/orange wire at the PCM does not work. That's the wire the diagrams at the12volt say to use. It's definitely a Vss wire, but the Z1 doesn't like that signal.

Yah, I don't know about the one on the PCM. But my friends 05 F250 works great with the gray/black wire on the ABS module. If you can find it in the dash, by all means use that.

Each time you change, remember to reset the VSS calibration info

MENU - SETTINGS - CONNECTION STATUS - 3D Calibration (or something with 3D, second one from the left I believe).

That way it won't have calibration info from one signal and then when it sees more calibration info from a changed source, it won't get confused.

If the truck didn't have the 6 disc changer, then there will not be a vss wire in the radio harness. Next best is as was stated before to use the same color at the abs module.

I finally got a chance to finish the F250 install. The truck did have the Vss wire in the radio harness. It worked fine once I got the truck up to a couple MPH. I could kick myself for not trying that the first time. LOL I've installed a couple other Z1s for buddies, though, and I've always gotten Vss pulses from just pushing the vehicle a few feet with the key on.

Thanks for the help. I might post some pictures tomorrow. The install came out really nice. We went all out with a video screen, amps, subs, components, etc.

Very nice, you will have to post some pictures.... I thought I posed some of the F250 I did with the drop down screen (and all the police radios, it was a cop's truck).

http://www.avic411.com/forum/viewtopic. ... 5&start=15

This is also a good f250 thread for info

http://www.avic411.com/forum/viewtopic.php?t=2301