Gary820
Well-Known Member
Right folks have an issue with the heater on the 80 (97 vx petrol with auto ac), set to cold it's well cold, ac on or off, auto on or off. Now adjust the temp off cold even a couple notches it goes full hot, nothing inbetween regardless of setting. It stays like that untill slide back to cold.
When it's hot the ac doesn't do much to cool it!
Switched the auto on the back of the heater panel off, no change. It's had a panel as it was playing up anyway.
Tested the system as per the FSM (have them from dealer next door) and all voltages etc all come back as they should, all sensors return the correct values, basically states the amplifier is at fault. now it has 2 different control units and a couple of amplifiers (ridiculously over complex system imo, why so many control elememts) well they've been swapped with a known good vehicle and no it's not any of them. Little temp sensor on the panel (has a white tube going to the heater box) is good too.
Dash has been out and the heater box checked to make sure no issues there, it's now been modified mechanically so the blend flap can't open more then half way, still a pretty warm heater at half way tbh but it's better then driving a sauna!!! No wiring corrosion, no water leaks etc..
Valve on the bulkhead gets operated by a little motor and opens when it goes to hot setting, closes on cold setting. Rear heater works as it should.
So any ideas before it gets a cable fitted lol. this is the last of the niggles I've got with the old girl!!
Anyone had similar?
Read various where people had issue's with the amplifier units but doesn't seem to be those!
When it's hot the ac doesn't do much to cool it!
Switched the auto on the back of the heater panel off, no change. It's had a panel as it was playing up anyway.
Tested the system as per the FSM (have them from dealer next door) and all voltages etc all come back as they should, all sensors return the correct values, basically states the amplifier is at fault. now it has 2 different control units and a couple of amplifiers (ridiculously over complex system imo, why so many control elememts) well they've been swapped with a known good vehicle and no it's not any of them. Little temp sensor on the panel (has a white tube going to the heater box) is good too.
Dash has been out and the heater box checked to make sure no issues there, it's now been modified mechanically so the blend flap can't open more then half way, still a pretty warm heater at half way tbh but it's better then driving a sauna!!! No wiring corrosion, no water leaks etc..
Valve on the bulkhead gets operated by a little motor and opens when it goes to hot setting, closes on cold setting. Rear heater works as it should.
So any ideas before it gets a cable fitted lol. this is the last of the niggles I've got with the old girl!!
Anyone had similar?
Read various where people had issue's with the amplifier units but doesn't seem to be those!
