Heater Control Unit

[chris1972]

My fan heater has stopped working inside the car. Nothing happens when I operate the switch. The dash top is off and everything seems connected and the LED behind the switch is illuminated. The ribbon doesn't seen to be damaged or corroded. Is there anyway I can test the heater control box? How do I do it?

[chris1972]

[Trevor450]

I wouldn't have a clue. People have had issues with the plug where it goes into the side of the unit though IIRC. Is the fuse for the fan OK?

I suppose that if you found the wire from the control unit to the fan, you could put 12v to this to rule out the fan but I suspect that this may be better left to a sparky.

[chris1972]

Is there nothing available from other vehicles?

[Trevor450]

I think it is a bespoke part but I may be wrong.

[Julesprivate]

Just reading back a lot of the issues seem to have been with the blower motor itself seizing, if you can manage to get to the wires for it and put 12V across it (or do a resistance check across them) that'd point you in the right direction.

Seemingly a right royal PITA to get to though sorry...


EFS - actually reading a bit more it seems to be a mix of Heater Control Units and Fan Motors so it could easily be either (or the 15A fuse)

Edited by Julesprivate on Friday 16th August 15:08

[Julesprivate]

There's on on eBay at the moment but you'd be better off testing your motor before spending the money (I'd have thought)

http://www.ebay.co.uk/itm/TVR-Chimaera-Heater-Cont...

[chris1972]

Julesprivate said:

Just reading back a lot of the issues seem to have been with the blower motor itself seizing, if you can manage to get to the wires for it and put 12V across it (or do a resistance check across them) that'd point you in the right direction.

Seemingly a right royal PITA to get to though sorry...

Thanks. Where is it, under the pax footwell?

[Julesprivate]

chris1972 said:

Thanks. Where is it, under the pax footwell?

Yep - early cars (pre 95 i think) had an access flap for you to be able to clean & lubricate it - later ones don/'t and it's rivets and mastik removal :-(

[chris1972]

Thought as much. Will leave it till winter to fix I think! Thanks for the heads-up.

[s6otty]

Pretty sure I've got a spare one of these, if you need it give me a shout.

Scott

[chris1972]

s6otty said:

Pretty sure I've got a spare one of these, if you need it give me a shout.

Scott

Cheers for that Scott, will do. Will get round to testing it later this week.

[S7Paul]

My heater blower failed a while ago. I was keen to make very sure I eliminated every possible cause except the motor, because it's a pain to remove. As it turned out, it was the control unit, and it seems like it's a fairly common problem. One of the terminals isn't man enough for the job, overheats and causes the failure. Before you do anything else, remove the control unit, open it up and check all the terminations inside.

[chris1972]

S7Paul said:

My heater blower failed a while ago. I was keen to make very sure I eliminated every possible cause except the motor, because it's a pain to remove. As it turned out, it was the control unit, and it seems like it's a fairly common problem. One of the terminals isn't man enough for the job, overheats and causes the failure. Before you do anything else, remove the control unit, open it up and check all the terminations inside.

Thanks!

[over_the_hill]

see here

http://www.pistonheads.com/gassing/topic.asp?t=585...

and here

http://www.pistonheads.com/gassing/topic.asp?t=760...

maybe some help