Exmoor Beast Posted December 1, 2013 Share Posted December 1, 2013 I had a bit of spare time earlier so thought I'd investigate why the heater stopped working in the 110 a couple of years ago. I had a quick look at the fuse, being ye-olde-glass ones it looked OK so I fired the engine up and thought I'd have a quick fiddle with the connections as far as I could see them. I turned the switch to 2, popped the bonnet and went in search of bits to wiggle, noticing a connection just outside the heater box I pulled it apart to give it a clean and noticed it felt quite warm, odd? Anyway, alarm bells rang so I went back to the fusebox and pulled the fuse to see it was a 35A one, checking the fuse layout I have it should be 10A...errr... I haven't got any 10A fuses so I can't replace it to see if it blows but I'm thinking it would. Why is the wiring getting hot? An ideas what to do next folks? Will :-) Quote Link to comment Share on other sites More sharing options...
western Posted December 1, 2013 Share Posted December 1, 2013 where the wires go into the heater case, there is a resistor, item 4 in http://lrcat.com/#31/4/52984 maybe that's dead & the wiring is getting warm due to to much current does the fan/motor turn easily ? remove the air intake grille from top of wing & then you can get a hand/fingers in the duct to see if the fan/motor will turn. Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted December 2, 2013 Author Share Posted December 2, 2013 Thanks Ralph, I'll have a look :-) Will Quote Link to comment Share on other sites More sharing options...
GW8IZR Posted December 2, 2013 Share Posted December 2, 2013 An appropriatley specified or sized connector only gets warm because its resistance has gone high. The current may be much lower than expected yet it may still get warm, clean the contacts or replace them and the joint should then behave normally.. It is possible that the motor is jammed or stalled and the increased current was blowing the correctly sized fuse, maybe someone tried a bigger one but if it isn't blowing the 35A fuse and the joint is getting warm you have two problems. Free up the motor to make sure it draws the correct current and clean the joint to make sure it allows current to the motor and doesn't get hot. For interest - the power dissipated (heat) in the joint is the square of the current times the resistance, dirty or bad contacts have high resistance. A good clean joint carrying 10A with a low resistance of 0.001R will dissipate 100mW - that will feel cold A bad joint with dirty contacts carrying just 1A with a high resistance of 10R will dissipate 10W - that will feel hot. HTH Quote Link to comment Share on other sites More sharing options...
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