when i turn the fan switch on the a/c the large relay on the side if the delamair clicks in each position of the switch but the fans dont come on, i have to switch the selector
back and forth and they eventually the fans will start, even on demist.., once there on they stay on until i turn the ignition off then they dont start again when i resume the trip, and i i have to repeat the abuse of the fan switch, does this point to a faulty relay or something not so easy to fix,?

 

Rex
Lower dash off, on the wing side of the blowers dangling from them you will find the power loom connection. The actual connector is a grey two-wire affair. If you unplug it (bit of a strugle to find it) then you can use a test light on the loom end of the plug to see if one of the two wires is live or not. If not maybe relay.
If you then go through your routine and the wires goes live, more proof.
If that is what it proves to be, the relay cover can be taken off, and you may find a corroded relay arm. I also have a feeling that the Great Palm has a scheme to use individual ones in place of the large OEM (NLA) one.

 

thanks gregg, nice little job coming up then,

 

Just to rule out other things, does the amplifier have anything to do with fans operating or not, I puchased and fitted a second hand shot gun cartridge type amp
and as it was condition unknown I'm wondering if that could cause the problem,, i found that the fuse that oporates the fans was a loose fit in the holder, now ive tightened that the demist works
straight away.

 

Also,

RHD, up behind the glovebox, mounted to the heater Inlet pipe is a "pad style" thermo switch. They play up, so join the wires and be done with it.

BUT

The fault you have has NOTHING to do with that switch, just advising an old age related issue yet to annoy you.

My Series cars mostly did that. Remove the radio, remove the Master Control knob. You will see 2 small hex (mostly) heads looking at your at 12 and 6 O'clock. Reach through the radio opening, and push you finger on the tiny nut (other end of the hex you see at the fascia), and tirghten the 2 through bolts. NOT Rock Ape Tight, just nice and firm.

That fixed all mine, and the XJS beasts as well.
I could not get a spanner in the backside, so the finger worked mostly, and a rag around the finger for the few that were just too thread bound for bare skin.

Amps?, no idea, never had one go out on me.

 

rex
I have a shotgun cartridge amp. In principle the amp can affect the fans, in as much as the signal from the amp to the cam servo unit moves a potentiometer and this activates the rods AND the signal to the blower relay. BUT what you describe as "curing" the problem at least temporarily, would be very unlikely to be caused by the amp-to-cam part of the system, as the cam servo unit would not suddenly start reacting to the switching you are doing, I am pretty sure, if it was not working.
So Grant's fix is favourite with the relay second, I feel.

As for amps failing, Oz must be to amps like it is to rust: does not happen. I have been through 4 in 20 years.

 

glad i didn't delve to deep after i fixed the fuse everything works again, thanks for all the advice though chaps.