S1 . . . . When the fan kicks in there is an eratic clicking sound around the ECU area and car starts to run hesitantly. When temp comes down, fan goes off and car runs spot again Is there a relay or something around this area for the fans ? I think there may be a back feed problem to the fuel pump possibly as i think i can hear it priming on and off during the fan being on but not sure. any help greatfully appreciated

 

Sounds like the wiring to the fan is causing a decent sized power drain, a new fan loom could do the trick

 

Car has twin Kenlows. Has override switch fitted to bring fans on as and when via a supply from switch inside car, to bring in 2 relays (one for each fan) Switch wire from stat also brings relays in. When fans brought in manually, car runs fine. When fans come in normally, clicking starts and car runs bad until fans go off.

 

disconnect the plug to the temp switch and use a bit of wire to bridge the connections inside the plug, if the car runs fine(i doubt it) then change the switch, if the car still buggers about then change the wirng to the plug

 

It's got to be the cars fan wiring circuit at fault when under load cos when the override switch is on and no load going through car fan circuit it's fine. Bridging the temp switch won't make a difference as this brings the cars wiring into play.(I'll try it though) There is a definite ticking/clicking sound around the ecu area which makes car judder each time it clicks when fans are on via temp switch.

 

Try it just to prove that's actually the problem

 

The clicking sound maybe the yellow relay on bulkhead change this as it supplies ecu ,ignition,fans
the override may use power direct from battery