1994lexus3

.....Ok so bought a referb. dash board it lights up and worked for a while then I killed engine and it went out clicked switch several times and came back on. Then shut off and workedfine for several tries I could here relay coming on then it did not work and relay under glove box never clicked and all was off. I ask before ad someone thought it could be, ECU is bad which one? The car seems to have several. Which ECU do you think needs to be replaced? When I turn on switch if I hear a click from relay under glove box everything works good but if no click is heard EVERYTHING IS OUT! Even the fan does not work. Is the ECU under glove box the problem and or what powers it?

Thank You

PFB

What exactly goes out? The lights, the gauges? What?

Does the car start when that happens? Why did you change your cluster?

More details needed

1994lexus3

The entire panel goes out no gauges the speedometer and the tack do not work, Changed the panel because it would work for ten seconds or so then the entire instrument panel would go black

1994lexus3

car does start but dash board is black.

PFB

Does the car start and run normally when that happens?

1994lexus3

Yes except at highway speed the car either shifts out of overdrive or will not go into overdrive when the instrument panel is not working

PFB

Even though it's a 1994, your car is OBD2. So you can use a code reader to see if you have any codes in memory.

Start with that at least.

1994lexus3

Can anyone answer this question, what powers the relay that clicks under the glove box just as you turn on switch when it clicks the panel lights up and everything is fine when it does not nothing works ie no speedometer, tack, no, lights on gas gage, nothing...also it has gone out when driving. The relay is called a circut opening relay it is behind the glove box does anyone know what sends power to that and if that powers the instrument panel.

LeX2K

From the service manual:

THE ENGINE CONTROL MODULE (ECU) OPERATION OUTPUTS TO TERMINAL FC AND CONTROLS THE CIRCUIT OPENING RELAY
AND THUS CONTROLS THE FUEL PUMP DRIVE SPEED IN RESPONSE TO CONDITIONS.

If the circuit opening relay is not working properly the car will either never start or the engine will die as soon as that relay is not energized or the circuit fails in some other way. The circuit itself gets power from the EFI fuse I believe.

LeX2K

K I looked over the wiring diagram a bit, when you lose power do things like the wipers, turn signals and cigarette lighter work? The combination meter gets power from the ignition switch/10 amp gauge fuse.