Pros and Cons, 4A Electrics

[ChrisR-4A]

For 15 years I ran my Electric fan (ex Fiesta) with a direct feed from the Ignition switch.

Never had a problem and could see the current it was taking through the Ammeter (8amps). It never stayed on for more than a couple of minutes even in temps of 40 deg and then only at tolls or in town after a motorway run.

Then last winter I took notice of the general advice given by many on the Forum and fitted a direct feed from the battery through a 35amp fuse and a relay, still using an over ride switch also from the relay.

All went well for over 1600 miles in France recently with temps up to 40deg until we got back to England and due to a delayed ferry we hit the Dartford Tunnel at rush hour with 4 miles of crawling traffic. Trying to pre-empt a rise in temp I used the manual over ride to leave the fan on, no indication on ammeter as it does not run through it anymore and after about

15mins at 0-5 mph I noticed the temp was climbing and the fan light was off, no fan and as its the only fan on the car the temp started to climb.

No hard shoulder but luckily before it boiled we found a layby and stopped. Investigation found the

Wire retainer next to the fuse had melted through the end of the fuse holder and the spring had pushed the fuse out breaking the circuit.

I made a temp repair using gaffa tape which got us home and have now fitted a clear plastic fuse holder from Maplins which is rated at 40 amps. I have run the fan for 15mins and nothing is getting warm so probably wont ever happen again.

So any suggestions as to why it happened.

Chris

[Lebro]

Probably a not very good connection between the fuse & the holder. any resistance there - given the high current being used by the fan will result in heating, which eventually will melt any plastic around it.

 

Bob.

[tthomson]

+1