Calling all EJs - I need some electrical system troubleshooting help. I've been trying to troubleshoot a wierd problem involving my cruise control and Modifry DCI.

In October, I had a reputable audio shop install all new upgraded stereo equipment. I had Modifry's DCI (that I had pulled from my MY'02 when it was totaled). The shop hooked up the speed control volume feature, which entails connecting the gray wire from the DCI to the vehicle speed sensor (VSS) wire on the convertible top control unit. Initially, everything worked fantastic.

Shortly afterwards, I tried using the cruise control for the first time (the car only has about 2k miles on it). I set it, but then it would randomly cancel. I could then reset it but it would cancel very quickly.

Strangely, I also noticed that the DCI would stop working after awhile, too (except for the mute button, which always worked).

So - I took it to the shop and they said, "It sounds like the DCI might be defective, and once it starts heating up, it fails. You should really install the 'Alpine' DCI." According to Modifry the "Alpine" is just a PAC DCI.

I really didn't want to give up on Modifry's DCI, so I decided to cut the gray DCI wire and see if I still had the same problem. I "thought" I had isolated it. The DCI now works all the time (except for the speed controlled volume feature, naturally), and I "thought" the cruise control was still exhibiting the same failure. But then I realized that what's really going on (at least now) is that with the cruise control on, any time I use my blinker, the cruise cancels. As long as I don't use my blinker, it seems to be staying on fine.

I checked my old Helms manual (for the '00 to '03 models), and it honestly seems like the cruise control circuitry is totally separate from the convertible top module and/or VSS wire.

I'm about ready to take it into the dealer, but because I had the stereo installed and they were mucking around with wires and such, I thought I would check with you guys to see if you had any ideas first.

Can anyone shed any light here?

Kathy

 

Anyone? C'mon, I know you guys are electrical geniuses.

 

To me it sounds like they tapped into a power source for the blinkers. In most cars, all the triggers for a multifunction lever are negative. Meaning the individual wires (since this car doesnt use data for that) rest at 12v and when a function is submitted (using the turn signal) the act of pulling or pushing the lever to go left or right is the trigger and thus changes the polarity from 12v to ground activating the relay or circuit for that particular function (the turn signal lights).

If it only does it when you use the blinkers thats my guess, but if it were through the dci's speed sense input something else is going on.

Does the dci stop working when you use the blinkers and the cruise main is NOT on?

 

The DCI is now working all the time, but I disconnected its speed sensor wire. What's weird to me is that it didn't work when the speed sensor wire was connected - but what does that have to do with the cruise control? It almost makes me wonder if the cruise had a problem from the outset - I just never used it before having the stereo installed.

 

did the speed controlled volume work properly when it was hooked up?

 

Yes, it worked great, except that after everything heated up (after about 15 or 20 minutes), the DCI wouldn't work at all, except for the mute button.