Low oil and battery light problem - big fuse

[TimJM]

Hi,

Last week my I had a problem with my oil and battery lights on the dash. They would both come on together very dim and become brighter with more revs this went on for a few days. Then the rev counter dropped to zero and both lights went out. My main beam light then also stopped working. When I tried to start the car the next day the battery was flat.

Having searched on these forums everything pointer to the big fuse so I took off the access panel and sure enough the big fuse holder had popped open. The fuse itself was completely submerged in water. I changed the fuse which is a fiddly little job especially as mine did not have a blade type 100A fuse that could be slid in and out it had a 125A fuse that went through the bolt holes. This meant removing the bolts completely and getting them back in which is not easy given the restricted access.

But, new 100A fuse in and all is well again. So, anyone out there whose oil and battery lights start to glow with high revs check your big fuse.

Tim.

[Extra 300 Driver]

IT should be a service item changed every 12 months or 6000 miles, just like the oil pressure spring.

[FarmyardPants]

A liquid cooled fuse - cool

[fatjon]

I assume there are more than one locations for this big fuse. My alternator light came on on saturday night then the car died on the motorway slip road with a flat battery. I found a big fuse, actually a metal strip between two posts in the alternator lead, down behind the coil packs. Replaced it and the light went out and 14 volts across the battery now. This is the first car I have ever seen to have a fused alternator connection.

Jon

[jammy_basturd]

I did want to search for this, but seeing as the search has gone AWOL, and there is this ready made topic I'll just ask here. Has anyone found an upgrade for the big fuse?

I only ask because the charging voltage in the Cerb has been 12.xV for some time now, and now the charge light on the dash has JUST started lighting up faintly. Hoping its the fuse, but prepared for it being the alternator too. Might change/refurb both at the same time just to make sure.

[Extra 300 Driver]

jammy_basturd said:

I did want to search for this, but seeing as the search has gone AWOL, and there is this ready made topic I'll just ask here. Has anyone found an upgrade for the big fuse?

I only ask because the charging voltage in the Cerb has been 12.xV for some time now, and now the charge light on the dash has JUST started lighting up faintly. Hoping its the fuse, but prepared for it being the alternator too. Might change/refurb both at the same time just to make sure.

This has been done to death many many times.

The best course of action is to replace the fuse every service, it costs pence.

[jammy_basturd]

• sigh* Yes, I know its been done to death many times, I for one have read many of the threads! I know its most probably the big fuse, however I can't rule out the possibility of the alternator yet as I haven't yet looked into the problem.

The search function is currently not working, and I'm sure I've read before that someone had changed the big fuse for a more robust/permanent option.

[Extra 300 Driver]

jammy_basturd said:

*sigh* Yes, I know its been done to death many times, I for one have read many of the threads! I know its most probably the big fuse, however I can't rule out the possibility of the alternator yet as I haven't yet looked into the problem.

The search function is currently not working, and I'm sure I've read before that someone had changed the big fuse for a more robust/permanent option.

You could fit a CB, but the rating would have to be over 100A, maybe 150A due to the fact that a 100A fuse does not blow at 100A!

You could also remove the fuse and join the cables, but that would be wrong in so many ways!

[Steve_T]

I'm wondering about a better place to locate the fuse - away from the heat and vibration where it's easy to change! Has anyone done this already?

[jammy_basturd]

I'm taking my exhaust manifolds off soon to repair and wrap them. I'm hoping this will cut the under bonnet temperatures, and make it a bit less of a hostile environment for all the components that live there. I'd rather try and have less heat in the engine bay, than over-protect everything because of the excess heat.

[GreenV8S]

Extra 300 Driver said:

You could also remove the fuse and join the cables, but that would be wrong in so many ways!

Care to name some of them?

[Extra 300 Driver]

GreenV8S said:

Extra 300 Driver said:

You could also remove the fuse and join the cables, but that would be wrong in so many ways!

Care to name some of them?

Its there for a reason, I dont know what it is but it goes against all my training to remove a fuse from a system and just link the cables together!

[Byker28i]

Someone replaced the fuse with a cartridge type one and relocated it near the front of the engine, someone else swapped it for a 100A Car Audio type fuse.

I've seen Steve Heath sell the midi typr which are stronger
https://delta.securesslhost.net/~shenglt/catalog/i...

and Clever Trevor? sell the cartidge type replacement ones.
http://www.tvrspareparts.com/part/540/125-amp-fuse...

[GreenV8S]

Extra 300 Driver said:

GreenV8S said:

Extra 300 Driver said:

You could also remove the fuse and join the cables, but that would be wrong in so many ways!

Care to name some of them?

Its there for a reason, I dont know what it is but it goes against all my training to remove a fuse from a system and just link the cables together!

If I was plagued with a car that had an unreliable fuse that routinely failed causing a breakdown, while giving no obvious benefit, then I would take great delight in chucking it in the bin and yes I would connect the wires directly together. Luckily neither of my cars have got the stupid fusible link in the first place so I don't have that problem.

[Extra 300 Driver]

GreenV8S said:

Extra 300 Driver said:

GreenV8S said:

Extra 300 Driver said:

You could also remove the fuse and join the cables, but that would be wrong in so many ways!

Care to name some of them?

Its there for a reason, I dont know what it is but it goes against all my training to remove a fuse from a system and just link the cables together!

If I was plagued with a car that had an unreliable fuse that routinely failed causing a breakdown, while giving no obvious benefit, then I would take great delight in chucking it in the bin and yes I would connect the wires directly together. Luckily neither of my cars have got the stupid fusible link in the first place so I don't have that problem.

It is a pain, but I changed mine and never had a problem.

[alinton]

All it does it protect the alternator in case something after it draws too much current, which is highly unlikely.

More trouble than its worth. Toss it out.

A.

[fatjon]

The fuse is there for a reason. If the rectifiers fail in the alternator you can get a short to ground through the coils in it, the battery will then dump several hundred amps through it for as long as it can. With no fuse and an alternator sat right under your fuel rails the results don't bear thinking about. The alternator is connected to the battery even when the car is not running and the ignition is off so in theory this can even happen while it's locked up in your garage. Don't frig the fuse out and disregard my earlier comment about other cars not having one, after some research I found that most do but it is usually a fusible link built into the wiring loom rather than a discrete visible fuse.

Jon