Adrian

Dear Herbie,
Looks right to me from what I can see on the wiring diagram. It is late and I am tired so I will get back to it, hopefully tomorrow. I am very busy tomorrow first thing so I might be a while,
Ciao,
Adrian
911C4

Herbie

OK, Adrian.

I tested arm contacts also on the control unit, that you told me where it was, and they are all OK, as I described two posts ago (waiting for your confirm).

Inspecting the control unit, have noticed a corrupted component, a diode, and oxide on the board, due, I guess, to water on the floor.

I've replaced the diode with a generic one, cleaned the board, and the C.C. now doesn't work at all;

(Don't worry, I've already remounted and tested all, my car is fine except for the C.C.)

On the C.C. unit there are 14 (13) pin, and I know only 4 of them (the ones coming from the control arm).

Thank you

Herbie

Herbie

Adrian

Any indication on CCunit connections ? (1..13)

Thanks in advance

Adrian

Dear Herbie,
Please email me tomorrow that you can accept an attachment and I will send you something so you can check all this stuff yourself.
Pin 1 is normally always the 12VDC input. 13 may well be the earth. I need to check this though.
Ciao,
Adrian
911C4

964Cab

Randall:

Do you recall the color code of that cruise control wire that your seat ran over ? I ask because I was cking the wiring under the seat regarding another problem and I heard the clutch or maybe brake micro switch activating as I moved wires about with my hand. Now my CC isn't working and the fuse is good. Was that a Yellow color coded wire ?

Thanks,

Patrick

Herbie

Adrian: well, I'll send you an email tomorrow, to receive attachment. Thank you.
But... can I remove the CCU without disconnecting battery, or will this generate a fault to be reset ?

964Cab: in the CCU of my Cab Tip the yellow wire (in the 13_pin socket) is the one corresponding to the "ein" position of the cruise control arm, see my previous post.

I too heard a "click" near the passenger seat, but it was the optional amplifier power supply wires, that are under the seat guide. Replaced the radio fuse.

964Cab

Herbie:

No I meant is the wire yellow that's under the seat in that 14 pin connector ? Is that the wire that feeds the DME regarding CC ?

Thanks,

Patrick

Randall G.

Hi Patrick,

My cruise control was repaired by a pro, so I don't know what the color was of the repaired wire. That said, it had to be a fused wire, as my fuse had also blown--presumably from when the seat track shorted the wire whilst running it over.

964Cab

Hi Guys (and Melissa),

Under the driver seat (USA) there is a yellow wire running to a mutil colored yellow wire through T-15. Anway, that yellow wire is the cruise control DMe "brain" wire. Also, under the passenger seat, as Adrian noted, is the CC relay and the CC control box.

I now have fine cruise control operation back again,

Patrick

Herbie

I'm working on my Cruise Control Unit, and trying to fix it.

On this unit, water caused a light oxidation, and a component, completely oxidated, is broken.

This is a diode, I suppose an 1N4148, like the one near it.

My problem is that I don't know the orientation to mount a new one.

Can you help me to know where the "cathode" (circled) terminal has to be directed ?

Looking at the board, from component side, with the big connector up, the broken diode is horizontal in the left lower corner, between two resistors. It's the last diode in this corner, near the board limit.

Seeing some functionalities I guess the cathode has to be to the right, but I'm not sure.

Thanks in advance

Herbie

964Cab

Herbie: Did you get that diode in right yet ? I have my CC control unit out and I see too many parts to ID the diode your talking about.

Patrick

Herbie

964Cab: if you look at the board, with the connector UP, and from the components side, then, in the lower-left corner there is one diode between two resistors.

There are a lot of diodes; the one I want is the nearest diode to the lower-left corner.

The lowest and the "more left" diode.

Its position is horizontal.

To better identify it, there is a link from its right terminal, on the component side, that goes round all the board, until near the blue connector.

I need only to know if is it a 1N4148, like the one near it, and especially if the cathode is at the right or left.

Thank you

Herbie

P.S. The cathode terminal, in that diode type, is identified with a black circle.

964Cab

Herbie: I put the CC back in the car as I have a strange CC problem that somehow I caused when solving another unrelated problem. My CC comes on only when I activate the CC arm AND depress and release the clucth pedal just a tad. If I don't do the latter the CC doesn't come on. Some how the CC clutch micro is backeards and only kicks the CC ON when I tap the clutch pedal a tad. You'd thiunk it would shut the CC off, instead of ON, when tapping the clucth pedal but not in my case.

I have my right seat out. Tomorrow I'll take the CC control unit out again and let you know what I can see diode wise.

I can't seem to find that clutch micro switch. The brake micro switch is easy to see but that clutch micro sw on my 5spd '90 C4 is hidden somewhere.

Thanks,

Patrick

Herbie

Dear 964Cab

I don't have a clucth microswitch because my car is a Tiptronic.

Looking at the CCU board, the clutch microswitch terminal goes straightly to the microcontroller, I remember, so it's impossible to determine how it works without the source of the program running on that MC.

My CC is not working, else I could try to supply various signal to that "Clutch microswitch terminal" and report you results I get.

There is a message in this forum about the microswitch position, with a photo too.