Discussion
I just discovered that the fuses for my cooling fans get very hot (when the fans are operating). The fans are staged and each has a separate fuse (25A) and relay, but the fuses get too hot to touch when the fans are running. The plastic body of one of the fuses has melted quite noticeably, but the fuse hasn't blown.
I'm not sure if the heat is being generated in the fuse element itself, or whether the contact between the fuse carrier (inside the fuse board) and the fuse has enough resistance to get hot.
Has anyone else experienced this or been able to fix it?
Peter
I'm not sure if the heat is being generated in the fuse element itself, or whether the contact between the fuse carrier (inside the fuse board) and the fuse has enough resistance to get hot.
Has anyone else experienced this or been able to fix it?
Peter
Ive got the same issue with my Ginetta, the plastic fuse bodies melt, but the fuses dont blow. I replaced the fuse holder for a better quality one, thinking it was a lack of contact area on the blade fuse, but the problem has persisted. I think at least some of it is down to the construction of the blade fuses- they are aluminum that's not the best of conductors, so they get hot around the contacts, and Im pretty sure blade fuses used to be ceramic, not plastic, so they would not have melted like they do now. The 30 Amp blade fuses used on modern cars for the fans are about 4 times bigger.
Mark,
Interesting point about the fuses being Aluminium - indeed the conductivity will be less than that of the copper wires connecting to the fuse holders, so it is probably predictable the fuse will get hotter. I guess one way to reduce the heat is to increase the amount of Aluminium in the fuse - i.e. use an over-rated fuse like 40A. I think I might try this. I'll also do a quick G**gle to see if ceramic carriers can be had - thanks for the suggestion.
Nice Ginetta BTW!
Cheers,
Peter
Interesting point about the fuses being Aluminium - indeed the conductivity will be less than that of the copper wires connecting to the fuse holders, so it is probably predictable the fuse will get hotter. I guess one way to reduce the heat is to increase the amount of Aluminium in the fuse - i.e. use an over-rated fuse like 40A. I think I might try this. I'll also do a quick G**gle to see if ceramic carriers can be had - thanks for the suggestion.
Nice Ginetta BTW!
Cheers,
Peter
The brand I bought was Auto King 100 piece box set (made in Korea). Don't think this will help you much as I'm in Australia. However I did buy them from a Halfords style auto factor. You can definately see and feel the difference in the quality of the plastic body. Just don't buy the stuff from China
petepetrolhead said:
Mark,
Interesting point about the fuses being Aluminium - indeed the conductivity will be less than that of the copper wires connecting to the fuse holders, so it is probably predictable the fuse will get hotter. I guess one way to reduce the heat is to increase the amount of Aluminium in the fuse - i.e. use an over-rated fuse like 40A. I think I might try this. Nice Ginetta BTW!
Cheers,
Peter
Interesting point about the fuses being Aluminium - indeed the conductivity will be less than that of the copper wires connecting to the fuse holders, so it is probably predictable the fuse will get hotter. I guess one way to reduce the heat is to increase the amount of Aluminium in the fuse - i.e. use an over-rated fuse like 40A. I think I might try this. Nice Ginetta BTW!
Cheers,
Peter
I know this is an older post now but NO NO NO the fuses are there to protect your circuits, your cars! why would you want to risk you pride and joy by putting a higer rated fuse in, this may just mean your wiring is goin to melt!!!
This is not the answer.
If it is not contact resistane then it could be that your fan motors are getting tired and drawing more current than originally intended. Fuses do not blow the instant they exceed the rated current, to blow they need to get hot enough to melt. If the increase in current is subtle then I can see the fuse getting really quite hot without blowing.
I think I'd want to check what current is being drawn before trying to fix the problem. I'm sure fitting 40A fuse would work but it reduces the protection to the wiring, ultimately the wiring will melt if you take this too far.
If you measure the current draw then you can know whether you have a real issue or just a dirty contacts/crap fuse problem, hence that being the first step. How to do ti of course is a little trickier as most DVMs will measure a maximum of 10A so you will need to get hold of a higher rated ammeter. Got a friendly pro who can measure the current for you?
Basically, it is best to understand the cause of the problem rather than just trying to fix the symptom. From the little I know of TVR's electrics it would not surprise me if the fuses were marginal originally.
Rob
P.S. I'm an electronic engineer, not a auto-electrician, despite the name.
I think I'd want to check what current is being drawn before trying to fix the problem. I'm sure fitting 40A fuse would work but it reduces the protection to the wiring, ultimately the wiring will melt if you take this too far.
If you measure the current draw then you can know whether you have a real issue or just a dirty contacts/crap fuse problem, hence that being the first step. How to do ti of course is a little trickier as most DVMs will measure a maximum of 10A so you will need to get hold of a higher rated ammeter. Got a friendly pro who can measure the current for you?
Basically, it is best to understand the cause of the problem rather than just trying to fix the symptom. From the little I know of TVR's electrics it would not surprise me if the fuses were marginal originally.
Rob
P.S. I'm an electronic engineer, not a auto-electrician, despite the name.
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