Hi, I have a diesel combi 1600cc Escort 1989. Lately I have been having over heating problems. While having to mess about putting in extra water every now and then, I noticed somthing strainge happen, somthing that defies explanation. ok.
Some years ago because I was going over onto the continent, I fitted a back up wire, a wire ready to tap into my baterries live terminal to bi-pass the switch that turns on the heater fan when in trafic, I never did trust the things. mind you, I have never had to put it on the live terminal until resently.
The other day infact. I had stopped to top up my rad as she was hot, the fan had not kicked in along with other things. I also noted that the engine was running at high revs, now, as I touched the wire onto the live terminal of the batterry to start the fan. I noticed that the revs dropped off on the engine by alot, I thought this was just a coincidence and thought no more of it. Some time latter when disconecting this wire to turn the fan off, the engine revs dropped at the same time. I tapped the wire on and off about six time to be shore and it did it every time. Now how can this be? the only other electrics going to my fuel pump is the wire going to the fuel on off servo, wich was okay or she would not have been running. And things like the temp sender and oil presure switch.
I have been over and over it in my head and just can not come up with any answer. SO. Any sugestions would be well welcomed.
It did it again today strainge. Still I think I have the over heating sorted as I found the bipass hose from water pump to thermostate houseing blocked, sort it tomorrow with luck. But any thought on this other would be great.
Cheers all Diesel combi Pete.

 

The fans are putting quite a load on the alternator and this drops the engine revs as it takes more power to run the alternator. You'll notice it on quite a few motors when you load up the electrics by switching on high load items such as fans, lights and heated screens.

 

Cheers for that mate. I was down my favourite auto shop this morning getting bit for my heating or cooling system and the chap in there knew streight away.
I now fill daff and I wonder had I not been haveing so much trouble with my combi over heating and other thing. 'Would I have seen this myself' ???? I us a Genorator quite alot. Still thank god some of us are awake Thanks again ,Pete

 

You will notice it on all cars, OP the fan switch does not switch the live, it is also very dangerous just to spur off the battery that feed has no protection!

Get the fans working SAFELY and properly, I would guess they aren't automated at the moment as you have modified the existing wiring?

Martin

 

No.. they are working great. I have not until latly had to use the wire, but it is fused with thirty amps inline, so should be safe. I hope I never need to use it again, but for some reason, I think it is because I never hear my fan kick in. I have always worried about being stuck in trafic and over Spain you would not believe some of the jams we have been in. But thanks for the thoughts, Cheers Pete