Tampa 928s

Cruse control, I bought one off of E-bay and briefly tested it on my Euro went to 45 Mph it did not engage. I tested vacuum servo per manual and everything checks out. I could not test the speed sensor but I assume its the speedo sensor the manual is referring to. One Abs sensor is out waiting on replacement or could that be the sensor they are referring to causing my problem.

Gtaebr

I had no set on my 86.5 and vacuum checked out good....

I pulled the "Cruise brain" (behind drivers side of center console) cleaned back of circuit board and resoldered all connections, as others have done and documented.

Cruise working fine now.

The solder joints get hairline cracks and no longer make good connections...this refresh should last years, well worth the effort.

Joe

Tampa 928s

Did anyone find out where the cruse speed signal comes from; the wheel sensors or tranny speed sensor?

Bill Ball

The speedo signal, which for an 86 is from the differential.

Tampa 928s

This is an 85 Euro:
I just checked the test procedures with unit removed and the only thing I found is this:
Pin 6 on unit shows 4.5 volts from brake switch brake off this should br 0 volts. With brakes pressed it does go to to 12v which is correct, I wonder where the 4.5 volts is coming from and maybe that this is why its not working. All other tests check out and I purchased a used one and since the car is in pieces its had to go for a ride and test it. I need to either return this or find out why its not working.
With car running and shorting pins as required it goes full throttle. I took my old one apart and re-soldered most of the contacts I must of had a solder bridge and it took off at wot. I found the bridge "eyesight is not as good as it was", so I know the vacuum portion is working fine. This leaves the brake voltage issue or a bad box.
Any feedback!

Lizard928

I believe that it opens and closes the ground connections.

Clean the ground connection just under the dash and verify that your E-brake switch is there and working properly as that could cause your 4.5V alternatively pull the 2 wires off the brake switch and see if it goes away then.

If it still does nothing then pull the plug on the Lampkontroller.
If you do all these things and it still is showing that 4.5V I think that you most likely have a shorted wire somewhere.

Tampa 928s

E-bake has one wire that grounds removed it, lamp control is removed. I beginning to think that since I have all the lamps disconnected getting ready for paint I have a floating ground and it maybe ok.