Login | Register
SearchMy Stuff
My ProfileMy PreferencesMy Mates RSS Feed
Reply to Topic
Author Discussion

wongthecorrupter

Original Poster:

1,132 posts

56 months

[news] 
Thursday 11th October 2012 quote quote all
Has anybody else had there heaters switch on for no reason, allthough it makes me laugh i think i need to fix them,any ideas gents.
Regards Simon

scruggs

352 posts

51 months

[news] 
Thursday 11th October 2012 quote quote all
Sounds like the Heater Control Unit. Metal box about 10cm square above the passenger foot well. A known source of trouble. Mine used to give me intermittent cabin heater/fans or sometimes fans that would not turn off.

Should be easy to get to, just find it and unplug the multi-pin electrical connector. Some people on the forum suggest sending it way to have a duff connection repaired. I took mine apart and cleaned up the circuit board and removed any corrosion from the contacts (internal and external). I also found a very small piece of solder, about 1mm round, that was stuck between two contacts. It must have been rattling around shorting across various connections.

wongthecorrupter

Original Poster:

1,132 posts

56 months

[news] 
Thursday 11th October 2012 quote quote all
scruggs said:
Sounds like the Heater Control Unit. Metal box about 10cm square above the passenger foot well. A known source of trouble. Mine used to give me intermittent cabin heater/fans or sometimes fans that would not turn off.

Should be easy to get to, just find it and unplug the multi-pin electrical connector. Some people on the forum suggest sending it way to have a duff connection repaired. I took mine apart and cleaned up the circuit board and removed any corrosion from the contacts (internal and external). I also found a very small piece of solder, about 1mm round, that was stuck between two contacts. It must have been rattling around shorting across various connections.
Thanks mate i will give it a clean up tomorrow.TVR's do so funny things.

Pacman1972

303 posts

147 months

[news] 
Thursday 11th October 2012 quote quote all
I'm glad someone brought this up.

Does anyone know if the vents on the MK1 steering cluster should blow hot air? - Mine just blow cold.
Also noticed the Air con is much colder on left most dash vent and gets progressively weaker across to the right.

Is this common on Tuscan or does it sound like a fault?

scruggs

352 posts

51 months

[news] 
Friday 12th October 2012 quote quote all
I have only had mine working for a week but the driver vents appear to be linked to the aircon.

The HCU is dismantled this way.

On the end of the unit opposite the multi pin connector undo the 4 black screws and remove the cover plate. This gives you a better view.

Half way down one side of the unit you will find a silver nut, on the opposite side is a hole through which you put your screwdriver to undo the screw attached. Catch the nut and drop the screw out of the unit (if it wants to). All this does is fasten the heat sink to the casing but a secondary effect is to secure the circuit board.

At the connector end undo the 4 black screws (not the 2 silver ones) and the circuit board should drop out.

Check that the 2 silver screws/nuts alongside the multi pin connector are done up tight, they can work loose.

A magnifying glass would be useful to check the row of several connectors on the edge of the circuit board for corrosion and bridging. On mine two connectors were intentionally 'bridged' together but any more need to be checked as loose metallic crap appears to be common place.

Clean up the board and connectors with yuor favourite abrasive, corrosion and crud promote electrical tracking.

Re-assembly needs to be via the heat sink screw first using a pair of tweezers to feed the screw through the heat sink, through the casing and secured by the nut.

Then refit the end plate screws.

Job took me 20 minutes.


Advertisement

ChrisnChris

716 posts

107 months

[news] 
Saturday 13th October 2012 quote quote all
I had my heater ECU refurbed, it was too damaged to try & sort out myself. When that was done the heater was only blowing cold, that turned out to be the stepper motor.
Reply to Topic