Heater fan

[tobeee]

My heater fan isn't working this morning in my T350! Difficult to tell if there's any heat being produced, as it's the fan that's not running, though the lights on the fan switch are showing. Is this likely to be a simple fuse fix, or something more sinister? I've searched the forums and seen mention of amplifiers and ECU's, but all that stuff is just too scary to contemplate!

[icraigmy]

It maybe the heater amplifier. I had the same problem and repaired the amplifier myself. You can get in touch with Neil at www.tvrcarparts.com and they will send it away for reconditioning (cost approx £100). The unit is situated beneath the glove box in the passenger footwell.

Hope this helps

[justyr]

Had this problem - same widget under the glovebox but was just a dicky connection on the ground lead to said box of tricks.
Unplug - replug and see what 'appens.
J

[tobeee]

Where, exactly, does this widget lurk? Is it just hanging around my wife's knees, or does the glovebox need to be removed to access it?

[rfisher]

There is a design fault in the heater amplifier unit.

I've also just repaired mine.

The unit appears to take a low power pulse input from the fan control switch ECU hidden in the depths of the instrument pod. This digital pulse is then boosted and output to the fan motor. Presumably the pulse frequency equates to the fan speed.

The fault is that the +ve output pin on the amplifier plug is of too narrow a diameter to handle the current output and gets very hot. This leads to a poor connection which decreases the energy dissipation within the amplifier and eventually blows the output capacitor.

I've not only replaced the capacitor but also wired a direct connection from the capacitor output to the fan +ve wire thereby halving the current carried by the output pin.

Works fine and is a modification that I would recommend to all Tam/350/Sag owners.

Usual disclaimers apply as I'm a bit of a fiddler and in the finest of British tradition I may be utterly mental.

[tobeee]

rfisher said:

There is a design fault in the heater amplifier unit.

I've also just repaired mine.

The unit appears to take a low power pulse input from the fan control switch ECU hidden in the depths of the instrument pod. This digital pulse is then boosted and output to the fan motor. Presumably the pulse frequency equates to the fan speed.

The fault is that the +ve output pin on the amplifier plug is of too narrow a diameter to handle the current output and gets very hot. This leads to a poor connection which decreases the energy dissipation within the amplifier and eventually blows the output capacitor.

I've not only replaced the capacitor but also wired a direct connection from the capacitor output to the fan +ve wire thereby halving the current carried by the output pin.

Works fine and is a modification that I would recommend to all Tam/350/Sag owners.

Usual disclaimers apply as I'm a bit of a fiddler and in the finest of British tradition I may be utterly mental.

Thanks for your responses. I took the car over to TVR Centre in Barnet, and, as usual, they diagnosed the fault and fixed it within 10 mins! Fix as described above.

[hab1966]

Before i pull the passenger footwell trim to pieces, can somebody tell me whereabouts i should start looking? Is it on the left hand side or somewhere above the footwell (below the glove box?)
Thanks.

[VARLEYHYD]

hab1966 said:

Before i pull the passenger footwell trim to pieces, can somebody tell me whereabouts i should start looking? Is it on the left hand side or somewhere above the footwell (below the glove box?)
Thanks.

Here we go:details here heatercontroller

Its possibly stuck on velcro, in the passenger footwell right at the back and looks like this




G

[julianc]

VARLEYHYD said:

hab1966 said:

Before i pull the passenger footwell trim to pieces, can somebody tell me whereabouts i should start looking? Is it on the left hand side or somewhere above the footwell (below the glove box?)
Thanks.

Here we go:details here heatercontroller

Its possibly stuck on velcro, in the passenger footwell right at the back and looks like this




G

Bloody hell, what a great website you've got!

[hab1966]

Ive located the controller along with a whole load more gubbins in the footwell that could probably benefit from a tidy up.

I did find what looks like a temperature probe down there, which i guess is related to the air-con? Can anybody confirm this?

[VARLEYHYD]

Careful with the capillary

thermostat should be set to max



G

[hab1966]

VARLEYHYD said:

Careful with the capillary
G

The 'thing' i found is not a capillary, from the quick look i had yesterday, im sure its a thermistor. I was just puzzled what it was for, as its not in the best position to measure any temperature.

[VARLEYHYD]

hab1966 said:

VARLEYHYD said:

Careful with the capillary
G

The 'thing' i found is not a capillary, from the quick look i had yesterday, im sure its a thermistor. I was just puzzled what it was for, as its not in the best position to measure any temperature.

That might be the hot or cold temp sender dangling loose. If so, it should be screwed into the air duct.

Have a look at my profile or my sagaris pages it,s all on there, how to sort in so it works properly


G

[justyr]

I've footered at length with this... 24 all round is indeed the best IMO. J

[tobeee]

justyr said:

I've footered at length with this... 24 all round is indeed the best IMO. J

Was this intended for the tyre pressures thread? I've noticed a coupel of odd random posts today, so I wonder if something's wrong with the website somewhere...

[shep1001]

icraigmy said:

It maybe the heater amplifier. I had the same problem and repaired the amplifier myself. You can get in touch with Neil at www.tvrcarparts.com and they will send it away for reconditioning (cost approx £100). The unit is situated beneath the glove box in the passenger footwell.

Hope this helps

There is a place in Luton near me (SEE ADDRESS ON THREAD)that recons these bits when they go tits up cost under 50 quid and 48hr turn round

http://www.pistonheads.com/xforums/topic.asp?h=0&a... (SEE BDV COMMENTS)

Shep

Edited by shep1001 on Tuesday 3rd March 13:45