Cruise Control - Speedometer Question

[JDFinley]

I imagine this question have been answered a dozen times so my apologies.... I just can't seem to find the answers.

I'd like to install a cruise control and have contacted thecruisecontrolstore.com for guidance. Their question is: "Do you know if it (speedometer) has a buffered speed signal output? The electronic throttle cruise kits are software based. We only have a handful of softwares built around a few different speed signals. We have to know the speed signal or we will have to glue magnets on a drive shaft."

I have a Mk3.1 with a 302, factory/Ford EFI, and a Speedhut speedometer (not GPS). I suspect I need to take the magnet on drive shaft approach given the comments I've found here but just want to be sure (and not create extra work for myself).

Thanks in advance and Merry Christmas!!

[weendoggy]

It depends on your transmission output. If you're using a T5 or TKO500/600 you can use the speedometer output side of the transmission using any gear and the VSS. You can also use the VSS signal on a TKO if you're not using it for your speedometer, or you may be able to "splice" those wires and call it good. Would need to know what you're doing in that department to help better. You shouldn't need to use the magnets.

I've been using one for 20yrs and it's the older vacuum operated Rostra, which is now an electronic one 250-1223 which has better PPM signal ranges, along with the 250-3592 control switch. Some of the newer transmission senders are OSS which may/may not work with their system, so you need to have your transmission I.D. sorted out. I will say it is nice on long open road drives.

[Mike.Bray]

Just out of curiosity, we have GPS speedometers are there not GPS cruise control systems? Is there a safety concern?

[GTBradley]

Personally, I think the magnets are the way to go. They are easy to instal and are very dependable and accurate. I've also read in the past that the transmission signal based ones have had problems with surging, but I don't really know anything about that, so take it for what it's worth.

[weendoggy]

I've also read in the past that the transmission signal based ones have had problems with surging, but I don't really know anything about that, so take it for what it's worth.

That "surging" can be controlled by the gain. A lot is just testing to find what setting you need. Just dip switches to set. I have no issues at all with surging.

[JDFinley]

Thanks all!

I have a T5 - think I'll go with the Magnet approach as Bradley suggested. KISS seems like a good approach for me! ;)

[GTBradley]

Thanks all!

I have a T5 - think I'll go with the Magnet approach as Bradley suggested. KISS seems like a good approach for me! ;)
The only thing I would suggest is look at the driveshaft area and make sure you can mount the transducer. My driveshaft safety loop was in the way, so I mounted directly to it, instead of the floor pan. Also, replace the speed nut with a nylon locknut - mine backed out on it's own.

https://thefactoryfiveforum.com/attachment.php?attachmentid=177037&d=1671576245

[weendoggy]

Thanks all!

I have a T5 - think I'll go with the Magnet approach as Bradley suggested. KISS seems like a good approach for me! ;)

Your T5 VSS will work fine. Just need to tap into each wire at the VSS. What could be more simple? jmo

[Bob Cowan]

The VSS will put out a signal that the CC can use. However, if you read the web site, they tell you that the most reliable signal comes from the magnets on the drive shaft. Bradley and I both use magnets.

If you have a stick shift with a clutch, you can also use an RPM signal, which might even be a bit smoother.

You can't use a GPS signal because it isn't reliable enough. Lose the signal - like trees, cliffs, tunnels - the CC shuts off.