CRT Issue

[BB89]

The CRT on my '89 is turning on and off with the engine running. Every time it comes back on it reruns the startup diagnostic. Then, on its own, it randomly rotates through the climate, radio and phone screens (this car does not have the phone). While doing this, without any input from me it has turned on the heater and maxed the volume on the radio. I was able to turn off the radio and heater when it cycled through the screens.

There are no driveability issues. I might have seen a flicker on the IPC which made me question if it is a voltage issue but nothing else is interrupted. The battery cables are tight at both ends and are in good condition.

Initially there were no error codes but I got some yesterday:

B335

C553

C710

C331 - I could not find a reference for this one.

I replaced the touch screen, the associated circuit board and the six buttons around the touch screen with good ones that I had on hand.

I checked all of connections and the wiring between the CRT and the CRTC -- no problems. I also checked the voltage going to the CRTC which was steady at 10V for as long as I had the meter attached.

I have had the intermittent screen wobble for maybe 6 years, and recently it has progressed to about half way up the screen but that seems like a different issue to me. This seems to be what is controlling the CRT rather than a display issue.

Any ideas?

- Bryan

[harry yarnell]

There is a CRT controller under the dash. This MIGHT be the problem. Have not run into this kind of problem.

[Guest crtnrds]

CRT possessed!