fan cuts in revs drop

[jayzcycles]

please help ,i cleaned the stepper and the car has been fine.last night when the car had warmed up sitting at traffic lights the revs dropped the fans kicked in then it was ok.as i got to home i pulled on the drive the revs started up down then the car cut out.can someone help .thank you.

[mongoose]

Often when the fans kick in,if the revs drop badly,it's the battery thats weak.

[RCA]

Yep, Agree with the above, I would look at getting the alternator tested perhaps. Brushes could be low or regulator on its way out.
cheers Rich

[Cider Andy]

The fans draw such an enormous current that they can make the engine revs drops even with a healthy battery and alternator.

[john57]

At least your fans cut in ....... which is why mine is currently residing at Austec

[deano400]

Its due to the load the fans put on the alternator and it has no load device to pick the revs up to allow it to produce the current needed.Hence the revs drop.

[that daddy]

when the fans first cut in the revs willdrop slightly because of the load on the alt,but the injection ECU should sense this revs drop and adjust the idle stepper motor accordingly to pick up the RPM if all is well.

[crackedfinger]

I have just fixed this on mine last week - for me it was the earthing strap between the engine block and chassis (behind drivers side front wheel). Everytime the fans cut in the engine struggled to run, and was getting little puffs of carbon/ brown smoke.

New strap was £3.99 from halfords, and the engine runs perfectly now.