Heater control unit

[p4pedro]

my heater fan is not working on a 2001 4.5 chim. also the 2 triangular leds and the circular red + green leds are not illuminating,( all other dash lights are working). Would a faulty / broken control unit cause the lights not to work as well as the fan. I have checked all fuses they are OK.

peter

[QBee]

The most common non-fuse reason for the heater fan not to work is a corroded over-heated terminal on the connector block to the heater control unit. This latter is a black box about twice the size of a 20 pack of fags, and it is located in the centre of the top of the dash, so pretty well behind the controls. Dash top off and you will find it, Disconnect the unit and have a look at the terminals. I bypassed my burnt out connection (just the one wire), soldering a new wire directly to the circuit board. There is a geezer who repairs these units for £50-80, and since mine failed a second time he has had my control box and switch for repair. I don't know his name, but he designed the thing in the first place.

I am pretty sure that this has nothing whatsoever to do with the dash lights. If they all worked before and none work now, then I guess it is possible that you have a different fault. My dash lights for the heater controls work fine. At present my heater control box and switch are sitting on my desk after repair, awaiting the return of enough courage and time to re-install it and re-route the diverted wiring - my TVR guy rewired it so that i had a permanently working heater while the bits were away being repaired, with a connector sticking out of the dash so that i could manually turn the fan on and off.

[Trevor450]

Hi Peter, yep, the control unit would cause this as it is connected through the controls and the fan. Quite often it is the multiplug on the control box that fails rather than the box itself. You will need to take the dash top off to have a look though.

Mark.

Beat me to it! ^^ The LEDs for the heater control do work off the control box though.

[QBee]

....it may just be that the permanent live to my heater fan is powering the lights then.....

[Trevor450]

When I had a bad earth that was just affecting the heater, I thought the box was at fault. When I unplugged the box, all the LEDs and heater illumination that usually come on with the ignition disappeared.

[p4pedro]

A loose earth was responsible for lights not working, I think the control unit is goosed.

[p4pedro]

[QBee]

No, it's that one connection that is goosed. Bypass it (requires soldering inside the box) and all will work again.

[Hut49]

I have a non-functioning heater control box that has already had the fix described (although the LEDs are working fine, just the fan switch is FUBAR'd). As the unit's end panel was cut through to make the direct connection it has probably rendered the unit non-serviceable/exchangeable. Anyone know of source of heater control boxes - or even just one ? Or is there a fix-on-a-fix solution?
Thanks for any suggestions!

[Hut49]

Hut49 said:

I have a non-functioning heater control box that has already had the fix described (although the LEDs are working fine, just the fan switch is FUBAR'd). As the unit's end panel was cut through to make the direct connection it has probably rendered the unit non-serviceable/exchangeable. Anyone know of source of heater control boxes - or even just one ? Or is there a fix-on-a-fix solution?
Thanks for any suggestions!

Does anyone have any contact info for Spimin Controls? The website is down for maintenance.

[Shiersy]

Speak to Jody at Python racing, he’s a TVR specialist in Essex and the guru on these control boxes, he does a postal repair service with quite a quick turnaround if he’s got time I believe

http://www.pythonracing.co.uk/electrical/

Dave

[Hut49]

Shiersy said:

Speak to Jody at Python racing, he’s a TVR specialist in Essex and the guru on these control boxes, he does a postal repair service with quite a quick turnaround if he’s got time I believe

http://www.pythonracing.co.uk/electrical/

Dave

Thanks for the help

[Hut49]

Hut49 said:

Shiersy said:

Speak to Jody at Python racing, he’s a TVR specialist in Essex and the guru on these control boxes, he does a postal repair service with quite a quick turnaround if he’s got time I believe

http://www.pythonracing.co.uk/electrical/

Dave

Thanks for the help

Thanks to Python Racing for reconditioning the unit so promptly and Mole Valley for removal/re-installation including rewiring the new connector. All working again