[DeTomaso] More cruise control issues (cruise-control-haters, delete immediately!)

[Christopher Kimball]

Dear SOBill, et al,

Today I tried using a resistor between the VSS wire and the 12v wire on the sending unit (3.3K since they didn't have a 3K), and it made no difference to the funky operation of my cruise control.  I tried various switch positions on the cc brain, including a vss pulse rate of 4,000 pulses per mile all the way up to 24,000 pulses per mile.  The 8,000 to 12,000 worked the best, but even then, the car lunges forward, then coasts, then lunges forward, etc.  I tried different positions with some of the other switches, too, to see if it made any difference--for example the manual said if the thing surges I should reduce the sensitivity, which I did.  I tried 8 cylinder "high" and 8 cylinder "low" with no change in the cc's behavior. 

I went through the entire self-diagnostic test built in to the cc unit, and everything checked out.

I tried taking the tach signal from the same wire that actually goes to the tach from the MSD tach adapter box, as well as the tach wire coming out of the MSD 6AL on it's way to the tach adapter--it made no difference.

I know the signal generator works since without it there was no response at all, if I remember correctly.  Plus, when I spun the rear wheel during the diagnostic test, the LED flashed as it was supposed to.

I'll call Dakota Digital again tomorrow to ask them what they think is the problem.  I hope I get someone who actually knows how to hook this goofy thing up!

Any suggestions would be appreciated.  Panteras Northwest has a big weekend drive coming up and I don't want to get to our destination with whiplash!

Sincerely,

Chris



From: SOBill at aol.com
Date: Tue, 8 Sep 2009 00:51:16 -0400
Subject: Re: [DeTomaso] More cruise control issues
To: chrisvkimball at msn.com








My VSS sender puts out  square wave.
 
The ZF speedo cable on my '74 turns 1 rev for each rev of the rear 
tire.
 
With a nominal 27 inch diameter tire, my VSS sender will 
produce about 12,000 pulses per mile.
 
Have fun,
 
SOBill 
Taylor
sobill at aol.com