Audiovox cruise installed - top speed is 68 mph??? - PeachParts Mercedes-Benz Forum

rgnprof · #1 05-19-2009, 09:44 PM

I got the Audiovox system installed and wired thru my stock cruise switch on the steering column. Took it for a spin and it works fine - with one noticeable problem.

The top speed it will hold is 68 mph... No matter where I set the cruise it drops down to 68 and then it holds fine. Really does a nice job holding the speed pretty constant, but I can't figure out why it only goes to 68 mph??

I am attaching a picture of how I hooked it up to the throttle at the valve cover - it is actually hooked up exactly like the stock cable, but I'm wondering if I have maybe restricted the length that the cruise cable can pull the throttle open??

Anyone got any ideas?

ryan

Oracle12345 · #2 05-19-2009, 09:51 PM

does any literature that comes with it have any insightful info?

just skimmed the owners manual and what do you have the ppm set to?

rgnprof · #3 05-19-2009, 10:00 PM

I have read, and re-read the manual and I am also wondering about the PPM... I set it to 2000 per the manual - options are 2000, 4000, 6000, and 8000.

Linkage was my only other idea...

rgnprof · #4 05-19-2009, 10:13 PM

I just found this website - I will try setting my ppm's to 4000 and see if that makes a difference.

http://www.edgesz28.com/edgesz28/cruise.htm

ryan

#5 05-20-2009, 06:22 AM

Are you sure it has enough movement range to pull the linkage far enough to go faster than 68mph?

Find a fairly long hill, set it to 68mph and see if it will maintain that speed with the added workload.

rgnprof · #6 05-20-2009, 07:38 AM

A long hill? In Oklahoma? Ha! I will take it for a drive today...

#7 05-20-2009, 07:42 AM

I lived in Oklahoma for 11 years, I know there are hills all over the place. Ever heard of Turkey Mountain? http://en.wikipedia.org/wiki/Turkey_Mountain_(Oklahoma)

http://www.mountainzone.com/mountains/state.asp?s=OK

pawoSD · #8 05-20-2009, 08:00 AM

I agree that the vacuum element is likely running out of travel before the throttle linkage is.

I will have to keep that in mind as I will be installing the same setup soon!

rgnprof · #9 05-20-2009, 08:08 AM

Yea, I know about the occasional Oklahoma hill! Just being funny - I'm not from here and I still haven't gotten used to the terrain....

Anyway, I have switched the ppm's to 4000 and I'm going to try that and see what happens. I'll post back later.

79Mercy · #10 05-20-2009, 10:01 AM

where did you buy this unit? Were you able to use the original switch? How much wiring is involved?

pawoSD · #11 05-20-2009, 10:18 AM

Quote:

Originally Posted by 79Mercy

where did you buy this unit? Were you able to use the original switch? How much wiring is involved?

I have the kit but have not installed it yet.

I got it on ebay a few years ago for just under $180.

Wiring = 12 volts to the system, it has its own wiring between its switch and the control unit (which is integrated into the vacuum thing under the hood), or you can splice it into the stock switch in the car. There also is a drive shaft sensor you attach to the shaft and then mount the sensor to detect rotation speed. Its a "project" but probably not that difficult to install overall. The biggest issue would be fabricating a bracket for the attachment to the throttle linkage on the cars with the electric actuator. I will have to do this....

79Mercy · #12 05-20-2009, 10:21 AM

180, i'd rahter buy 25 dollar cruise amps when they go bad.

rgnprof · #13 05-20-2009, 10:40 AM

I bought the unit from Amazon - less than $90 with the magnet kit included. On my '78 with the vacuum actuator, hooking up the cable was easy - the kit came with a bracket that fits the existing bracket on the valve cover, so that was easy (see my picture). I did have to manufacture a plastic grommet...

You only need to mount one magnet (rear wheel drive vehicle) to the driveshaft and I did this about 3-4 inches to the rear of the front flex disk. You'll have to finagle the bracket some, but it will work...

The wiring wasn't too bad to figure out either - using the wiring diagram and a voltmeter to double-check, I figured out which wires were 'hot' when I pressed the cruise switch on the steering column - #9 Accel/Set, #10 Resume, #8 12v, 0 volts when lever moved to OFF, #5 12V always, #6 12V when brake pedal depressed, #4 Decel/Set. Test with Key ON. Once you run the wires from the new cruise unit into the cabin, you will have 5 wires to connect - RED to #5, Brown to #8, PURPLE to #6, GREEN to #4, and YELLOW to #9.

So I wired it up the way a previous post described, using a junk amp and soldering the wires to the the correct pins and then plugging that piece in to my existing plug (the one that plugged in to the original cruise amp).

Works great - and changing the PPM setting to 4000 rpm, it now holds speed at 75 mph. Very responsive and everything works on the steering column stalk as before, except for the RESUME function. Now to RESUME, you have to press up and not toward you.

Hope this helps.

Ryan

pawoSD · #14 05-20-2009, 12:16 PM

Quote:

Originally Posted by 79Mercy

180, i'd rahter buy 25 dollar cruise amps when they go bad.

I've bought 2 or 3 of them so far, all didn't work. So rather than throwing money away on the stock system I picked up the audiovox kit.

A proper replacement cruise amp is like $350+....and if the actuator is bad too, there's another few hundred.....the audiovox kit is a much better solution....

pawoSD · #15 05-20-2009, 12:17 PM

Quote:

Originally Posted by rgnprof

I bought the unit from Amazon - less than $90 with the magnet kit included. On my '78 with the vacuum actuator, hooking up the cable was easy - the kit came with a bracket that fits the existing bracket on the valve cover, so that was easy (see my picture). I did have to manufacture a plastic grommet...

You only need to mount one magnet (rear wheel drive vehicle) to the driveshaft and I did this about 3-4 inches to the rear of the front flex disk. You'll have to finagle the bracket some, but it will work...

The wiring wasn't too bad to figure out either - using the wiring diagram and a voltmeter to double-check, I figured out which wires were 'hot' when I pressed the cruise switch on the steering column - #9 Accel/Set, #10 Resume, #8 12v, 0 volts when lever moved to OFF, #5 12V always, #6 12V when brake pedal depressed, #4 Decel/Set. Test with Key ON. Once you run the wires from the new cruise unit into the cabin, you will have 5 wires to connect - RED to #5, Brown to #8, PURPLE to #6, GREEN to #4, and YELLOW to #9.

So I wired it up the way a previous post described, using a junk amp and soldering the wires to the the correct pins and then plugging that piece in to my existing plug (the one that plugged in to the original cruise amp).

Works great - and changing the PPM setting to 4000 rpm, it now holds speed at 75 mph. Very responsive and everything works on the steering column stalk as before, except for the RESUME function. Now to RESUME, you have to press up and not toward you.

Hope this helps.

Ryan

Awesome, perhaps I will try and get around to installing mine soon!