Rev's jump when fans kick in

[pepper]

Can anyone help? When she warms up and the fans kick in, my rev's jump between 1-2k, making the car kangaroo unless I give it loads of revs...! Not cool off the lights...

[beano500]

They all do that, Sir!










Admittedly not to the extent you describe though

[victormeldrew]

Yup, the fans put quite a shock load on the alternator (thats why they are converted to two 30a fuses!) and the revs will flare to compensate. Should settle back though. Are your fans flipping on and off? Maybe there is a loose connection to the fans, or possibly the otter switch.

[pepper]

Yes, the fans come on after running for less than 15 minutes! (It's a '93 Griff, so it has it's faults!). I had a new alternator 4 months ago, but it's only recently started to happen... Hmm. Looks like a trip back to the garage...

[pepper]

Yes, the fans come on after running for less than 15 minutes! (It's a '93 Griff, so it has it's faults!). I had a new alternator 4 months ago, but it's only recently started to happen... Hmm. Looks like a trip back to the garage...

[simon.b]

I think it is a case of TADTS, but if you’ve only noticed it recently then check your earth’s as a poor one will make it worse (so I’m told).

Cheers,

Simon.

[tvr4ever]

simon.b said:

I think it is a case of TADTS, but if you’ve only noticed it recently then check your earth’s as a poor one will make it worse (so I’m told). Cheers, Simon.

Mine is a 93 one also, no problem with revs etc. So probably not a case of TADTS. Like you said I would check the earth, I clean mine once a year. So my guess would be the earth.

Fred