Idleing electrical question

I have a query in relation to my 68B. I have recently installed a kenlowe electric fan to the engine removing the mechanical one. since installing this i noticed that the idle speed drops off when the fan comes on. i also noticed subsequently that the same thing happens when the headlights are switched on (not necessarily with the fan running at the same time). is this an alternator problem? It makes driving in traffic very difficult as the car keeps cutting out. The alternator was replaced about a year ago with a stock replacement item and i think that the battery is in good shape too.

Thanks for any ideas in advance.

Nicholas.

I had the same problem when all the elects were on at night. with everything off it would idle at 800 to 850 with all on it would idle at about 550 or 600 turned up the idle to aroung 1000 or 1050 with everything off and all is well.
you are just putting a load on the system i think what you are saying is normal but maybe somebodt else will know a lot more then me..

Dwight

What's happening is the extra load on the electrical system is causing the alt to charge more, thus creating an increased load on the engine. Just increase your idle some to compensate. The other way around this is to find an idle solenoid from an old car and rig it up to increase the throttle slightly whenever the fan is on-way too much trouble for a minor problem

at present the idle is set quite high. It is at around 1200rpm. This drops right off when the fan alone kicks in. I would not have thought that such a low additional load would reduce the idle so much.

Make sure your battery is at peak performance. If it isn't and is constantly taking a charge your situation will crop up. It's not the fault of the alternator, it's doing it's job or it wouldn't slow the engine down.

I ran the battery flat a couple of times before the alternator was changed so maybe that has done some damage to it. Is there a particular votage the battery should achieve if it is in top condition?

If you suspect the battery condition then get it load tested by your local auto sparky. This will determine if the battery is good or not. If not then buy a new one.

Russ