Cruise Control Options - Now that Cruise King is gone

[chessie4905]

When I got my 4905, it had a cruise control on it. Similar to a Rostra, but different brand unknown to me. The actuator cable was rusted fast. It was installed in engine compartment. If it was a Rostra, I would just have replaced it. Instead, I mounted my King under driver's compartment.. all my connections were up front. The speed signal came either from tach or speedo, don't  recall. Had an issue with it not retracting during setup. Called new King owner about issue. He said, I needed to change dip switch #1 to other position, since 4905 was auto and 4104 unit was from had a clutch. It worked then. That info wasn't  in my instruction sheet. The King is very heavy duty built, but with an air throttle, Rostra will be fine.

[luvrbus]

Unless Richard does a lot of flat land highway driving I question why he would even want a cruise on a 8v71,LS speed governor on the engine with a 4 speed manual transmission 

[richard5933]

Unless Richard does a lot of flat land highway driving I question why he would even want a cruise on a 8v71,LS speed governor on the engine with a 4 speed manual transmission

I rarely drive at governor. On rolling hills or flat the bus will easily cruise at 75+ if I'm not careful to keep the speed down. Only on steep/long grades do I need to keep the pedal to the floor.

On a trip to norther Wisconsin this past weekend I tried to keep the speed at about 65, but even through the rolling hills the bus just loves to go.

My problem is not lack of top end. My problem is lack of low end. Getting started on any type of incline is slow and tedious, sometimes to the point I worry I'll make it at a stop sign with a steep uphill.

[Jim Blackwood]

I wonder why you couldn't consider an all electric unit from one of the later generation Ford cars? (Mid 90's on) They use an electric motor driven actuator, probably a stepper motor, and have three components: the actuator which is reasonably compact and usually has a fairly long cable, the brain which is built into the actuator, and the switch module which can be popped out of the steering wheel. I think that's all there is except the wiring. It'll need a speed sensor of some kind, either road speed or engine speed. I've used them successfully in sports cars. I've heard the late model GM units are good too but I haven't looked at them yet. The switch module works on discrete voltage levels so it is just switches and resistors and you could probably get by with only one wire going back to the engine. I think the four connections are B+, B-, signal, and signal ground.

Jim

[richard5933]

For now I'm going to try and install a Rostra electronic unit. A few details to work out, but I think that with a few magnets mounted on the back edge of a front brake drum I should be able to install without any modifications other than running the cable to the accelerator pedal and the control switch wiring to the dash.

[buswarrior]

The trick to steady speed on the pedal is musical.

Listen to the machine, set the tone, keep it humming in tune.

Everything makes noise, engine note, exhaust, tires.

Find the rhythm that sings your desired speed.

Happy coaching!
Buswarrior

[richard5933]

Starting to get the install started on the new cruise, and have a question about the speed sensor...

My bus has the OEM electric speedometer installed by GM. The generator works but the speedometer itself was having problems so I switched to a GPS speedo.

Is there any way to use the output from the speedo generator for the cruise control's speed signal? Not sure if the speedo generator is producing a steady voltage or a pulsed signal, so hoping someone here will know. If it is pulsed, my thought is that this might be usable and mean that I don't have to mount magnets on the brake drum.

[chessie4905]

My King runs off the speedo signal. Just needed to select wire at the head. I'd try it. Just be sure to get the signal wire. If that doesnt work,  epoxy magnets to brake drum flange and mount the optional speed sensor. I used two magnets opposite distance on Burgman. Btw, my speedo is a Dixson.
You can also contact Rostra if it doesnt work.

[oldmansax]

FYI, BadAndy over on the Wanderlodge board used all 90s model GM components to replace the Bendix cruise that came on the 6V92s. Works like a charm.

Of course, he is a electronics wizard and runs all his ACs on a battery setup that actually works. LOL! He says the cruise hack was easy but that's like Clifford saying something on a Detroit is an easy fix!   

TOM

[richard5933]

Continuing with the install prep...

The installation guide calls for putting the magnets on the driveshaft or a front axle. I called tech support at Rostra today to get information on how to set the DIP switches if mounting the magnets on the back edge of the brake drum. The guy wasn't much help.

He said that if I followed the instructions and did it on the driveshaft, I'd end up with 2,000 pulses per mile and use that setting. A bit confusing, because the number of revolutions per mile would really depend on the rear axle ratio & tire size, but he was dead set that it's always 2,000.

So, my tires (Firestone FS561 12R22.5) are spec'd to rotate 487 times per mile. Assuming that means my brake drum will also rotate 487 times per mile, and with 4 magnets mounted on the edge of the brake drum, I'll have 1,948 pulses per mile.

My only fear is that the thing needs to see the 2,000 pulses precisely, but I don't see how it can be a hard number like that. I'm assuming that the Rostra cruise will be fine with this and continue to function. Does anyone see a problem here?

[chessie4905]

On the Burgman, I glued two magnets on rear wheel and it worked fine. Remember you are selecting the vehicle speed you want it set to. It uses that signal to maintain that speed, it doesn't know what that speed in mph is. it just knows what the sensor speed signal is and locks on to that. I don't like the magnets on the driveshaft idea. The shaft is too short to work with, requires long wires,  tricky to mount the sensor,and is hard to access. I would try the signal wire from speedo too. Could make wire up really easy.

[richard5933]

On the Burgman, I glued two magnets on rear wheel and it worked fine. Remember you are selecting the vehicle speed you want it set to. It uses that signal to maintain that speed, it doesn't know what that speed in mph is. it just knows what the sensor speed signal is and locks on to that. I don't like the magnets on the driveshaft idea. The shaft is too short to work with, requires long wires,  tricky to mount the sensor,and is hard to access. I would try the signal wire from speedo too. Could make wire up really easy.

Thanks.

I did look into using the speedo, but it looks like the OEM unit uses voltage rather than pulsations to make it work.

I understand about the cruise just comparing the pulsations from one moment to the next. What I'm confused about is why there is a DIP switch setting for this at all. Why does it need to have a setting of 2,000 or 3,000 or 4,000 and up to 38,400? Maybe to give it a frequency to look for?

Also confused why the tech said that all cars with rear wheel drive using magnets on the driveshaft will have 2,000 pulses/mile - there is no way all cars spin their driveshafts the same speed.

[chessie4905]

I think you are over thinking it. I think the dip switch setting is probably what works best for response or accuracy of setting you can always change it to see if a different setting works better

[freds]

The cruise control unit needs to know the pulse rate in order for the increase or decrease speed functionality to work for the +/- 5 mph functions.

Also some units have a 20 MPH minimum engagement speed.

[buswarrior]

Likely, too few pulses, the unit will surge speed up and down. Had one like that years ago in a car... useless...

If the tech is adamant about this 2000 setting, it is for a reason, whether how he explains it is any good, matters not.

Happy coaching!
Buswarrior