Heater control troubleshooting

[SergSC]

Heater has a mind of its own these past few weeks.

It often doesnt work (go to hot) when turning the car On from cold, if I forgot to put the heater Off the previous night when putting the car to bed.

If I switch it off before turning the car off, then it almost always works properly when starting the car from cold the next morning, until the next time I turn the car Off/On while hot.
For example, if I drive the car from cold for 5 minutes with heater On, then turn off heater, turn off car, buy petrol, then back On, then it wont work again until the car goes completely cold again...

Sometimes a heater stepper error comes up, sometimes not.

Sometimes but increasingly rarely I can get it to work again If I fiddle the temp and fan speed controls.

Sometimes if its working on hot it switches itself to cold without me thouching any controls.

Any idea? Before I start replacing parts at random.

Cheers
S

[JRH63]

On my Tam it was the connector to the control unit in the pass side footwell.
The connector gets too hot, you will see that it's 'scorched'
I soldered the individual wires direct to the pins, it's been perfect ever since.

[mk1fan]

Helpful link;
http://www.pistonheads.com/gassing/topic.asp?h=0&a...

My fans stopped working so will be stripping out this weekend.

[JRH63]

If you look at the pins, they are too loose a fit into the female steel tubes in the connector. Remove the female pins from the connector and nip them tighter..... Or solder. Simples....

[EvoOlli]

The above problems are more related to the DashECU in the DRIVERS footwell and the connection between the switches and the DashECU.
They can't have anything todo with the amplifier in the passenger footwell.

First I would check all connections to the DashECU (4 plugs in the drivers footwell, in front of the A-Pillar). Then I would check the connection between the switches left from the Instrument Binnacle. These are connected with ribbon cables to a collection board behinde the DashPod.
If this doesn't help I fear you have to send in the Dash ECU to Paul Smith for repair.

[SergSC]

Thanks guys, I'll check all the connections. Hope its not the dash ecu, again, as its only just been.
Cheers

[SergSC]

Think I found the cause. The capacitors look swollen, like they are about to burst and shower the OH's legs with hot stuff. I guess they still work for a short amount time after starting the car from cold, explaining the symptoms.

I bought caps from maplins, 1000uf 63V 105c temp rating (more durable apparently), but I think they are a tad smaller than the standard?

Anyway, the plan was to take the module out and solder them on, but I cant see how its attached, any tips?
Then to relocate to glove box area as per the other thread, any more pointers re doing that?

Many thanks
S

[shep1001]

SergSC said:

Think I found the cause. The capacitors look swollen, like they are about to burst and shower the OH's legs with hot stuff. I guess they still work for a short amount time after starting the car from cold, explaining the symptoms.

I bought caps from maplins, 1000uf 63V 105c temp rating (more durable apparently), but I think they are a tad smaller than the standard?

Anyway, the plan was to take the module out and solder them on, but I cant see how its attached, any tips?
Then to relocate to glove box area as per the other thread, any more pointers re doing that?

Many thanks
S

Case is screwed & stuck with a pad in place, well mine was anyway but its a TVR don't forget! Get down and have a good look its not difficult once you have twisted yourself into the correct position!