fan stealing power.

[SCHWARTZ]

Every time the fan comes on the Afr's go into the 10's:eek: and it tries to kill the engine, when the fan swiches off everything is normal again:scratch:
I have my fan wired on a seperate circuit taking power from the alternator, where the looms take their power. Should the fan really be taking that much power or could there be a fault with the fan? Seems to work well tho. Would taking the power for the fan from the battery instead of the alt help?

[Markey Mark (BD)]

I would say the fan itself is drawing the power and is loading the alternator up

Maybe try another fan unit mate

[SCHWARTZ]

I sorted the last problem, was just a loose connection on the starter:rolleyes: now this. I'm sure it has been doing it a while but now I have changed the alt its more noticeable. Is it ok to take the feed for the fan and the looms from the alt? Could a bad earth for the fan cause this? I will have a look for a new fan was looking for a nice slim one anyway:wasntme:

[Markey Mark (BD)]

I sorted the last problem, was just a loose connection on the starter:rolleyes: now this. I'm sure it has been doing it a while but now I have changed the alt its more noticeable. Is it ok to take the feed for the fan and the looms from the alt? Could a bad earth for the fan cause this? I will have a look for a new fan was looking for a nice slim one anyway:wasntme:

I take the feed for the fan circuit from the alt +terminal, i use the diesel wiring curcuit so not sure if thats same as yours but it basically goes through fan switch and then onto fan

Just wonder if your fan is getting old and drawing abit more current which pulls the alternator down

[SCHWARTZ]

I have power from the alt to a relay then to fan and temp switch triggers it. Can I do away with the relay then and just go from alt to temp switch then to fan?

[Markey Mark (BD)]

I have power from the alt to a relay then to fan and temp switch triggers it. Can I do away with the relay then and just go from alt to temp switch then to fan?

Actualy mine does have a relay too but its a fair bigger one compared to the gt turbo relay, mine dips alittle when the fan kicks in but not a great deal
I'll see what relay it is and see if Mike could poss source a few of them

[SCHWARTZ]

The whole relay circuit seems to work well allways comes on but just saps all the power I'm gona double check the earths for the fan, if no change il take the feed off the battery then if still no joy il order a fan.

[Nick k]

My old engine did exactly the same thing, Fan cuts in and it sputtered or cuts out, Did my rack in :brickwall: Never did work out what was causing it??

[SCHWARTZ]

Poxy things:laugh: if I get to the bottom of it il let ya know;)

[Scoff]

If the fan makes the idle rpm drop noticably then it might just be that the ECU's map is dropping in to a different load cell which may be richer than the one it's in during normal idle. If you have a bypass pipe then the map will be up the wall anyway.

Or, if it's the old GT style fan then I had no end of trouble with those in cars with standalone. They generate a load of inteference compared with a modern brushless jobbie. It might be that the fan is intefering with a sensor, like air or coolant temp, or MAF signal, etc.

Or, it could be a crud earth somewhere that's causing a sensor to misread when the fan is running.

I bet if you swap to a decent modern brushless fan then you'll be ok.

[SCHWARTZ]

Yeah it is a standard fan, when it comes on idle drops sometimes stalls and goes really rich. Looks like I may need a new fan then.

[SCHWARTZ]

Got a little time with the car so I gave the fan anorher earth, no change. Gave it power from battery not alt, no change. So looks like I need a new fan, the battery holds 12.33v when I turn the fan on that drops to 12v with the engine off but with the engine running there is little to no change. So my basic understanding is that everything is working ok but like you say scoff there is interference from the fan. :scratch:
So the only way to sort this is to get a new fan then I guess.:rolleyes::D

[SCHWARTZ]

I have half sorted the prolem, turns out the fan was blowing air down the bypass hole and that was messing up the maf and making it rich. I have made a little plate to shield the bypass hole from the air which helps but only gets it into the 12s:mad: