blade fuse values please!

[zygoma999]

hi there. as i've seen from other threads, fuses burning out in the fuse box on top of the battery is a common problem. i have a '99 t plate toledo 110 tdi and the only fuse that seems to have got hot is the blade fuse on the far right as you face the engine bay. i basically need to know what the value of this fuse is (as its burnt away!) and what it is for.
the owners manual has not been helpful as it shows 5 blade fuses whereas mines got 4 and the values are different. the values on mine from the left are - 110a,110a,40a and then the burnt one. i've been in touch with seat and they were a waste of space! can anyone help me?!

 

[glynnd]

Has your car got air con?
If so then do the air con fans come on?
Dose your radiator fan work.
I had the common problem of the air con fans not working on my leon which when I repaired with two resistors managed to blow one of the fuses you are talking about. I believe the one you are talking about is also a 40 amp and could be the fuse for the air con fan circuit or your radiator fan.
Hope this may help you
Glynn

 

[zygoma999]

cheers glynnd. my toledo has got aircon and when i turn it on both fans work as they should. everything seems to be working ok, no warning lights so i presume that the fuse has not blown despite how it looks! are you sure that its a 40 amp fuse - if so, i'll order one? any other idea what that fuse protects?
cheers again.

 

[glynnd]

cheers glynnd. my toledo has got aircon and when i turn it on both fans work as they should. everything seems to be working ok, no warning lights so i presume that the fuse has not blown despite how it looks! are you sure that its a 40 amp fuse - if so, i'll order one? any other idea what that fuse protects?
cheers again.

Tbh I cannot b 100% sure I am correct but its a 40 amp fuse that controls the fan for the ac and the rad fan.
Noticed anything thats stopped working?
Difficult with the rad fan as it does not come on much and is very quiet.
Make sure its working b4 summer gets here!
Glynn

 

[Muttley]

First let's be certain we're talking about the same thing here.

Fusebox mounted on top of the battery, has positions for five big fuses and three smaller ones. The big ones are what I'm assuming you're calling "blade" fuses, but I think of the smaller ones as blades, because they have two big blade connectors on the bottom that fit into sockets on the fuse panel. The really big fuses in the battery-top box are unlike any other fuses I've seen, metal strips that are screwed down at each end, to make sure of good contact. These are high-value fuses, a lot of current is going through them, so good contact is essential.

All the books I've seen show five screwdown fuses in there as well, but mine only has four of the positions occupied, as does yours I presume.

The fuse values on my 51-plate Toledo TDI 110 SE (which has aircon) read 100A, 100A, 40A, 50A left-to-right. Above and to the right of them are three plug-in blade fuses, all green 30A ones.

Pics:

Battery-top fusebox location

Battery-top fuses, close-up

Battery-top plugin fuses

Fuse positions are labelled as follows in the electrical diagrams.

Standing in front of the car, going from left to right, first the flat screwdown metal strip fuses

S177	110A	Alternator
S176	110A	Interior
S164	40A	Radiator Fan
S163	50A	Engine Management
S162	50A	Glow Plug Heater

and the plugin blade fuses are

S180	30A	Radiator Fan
S179	30A	ABS
S178	30A	ABS (pump)

So in mine at least the one that is missing appears to be the Glow Plug Heater.

Just for reference, what engine code is yours? Mine is ASV, but yours being earlier might be AHF or something?

I'm sure I've seen other threads about water getting into this box and corroding the contacts, which leads to higher resistance, which generates heat as the current flows through, which eventually blows the fuse. I think this particular fuse location gets wet first or something?

 

[zygoma999]

cheers for that comprehensive reply muttley! my fuse box looks exactly the same as yours but mine is the ahf engine number. the furthest right of the 4 blade fuses (50a) is the one that has corroded. from your info the 5th position is for the glow plugs which is empty on ours. do you think that means that the 4th one is for the glow plugs and we dont have the 50a engine management fuse?
the only problem with my tolly is that, when its warm, it turns over for a few more secs than it should before it starts.
look forward to your reply and i'll order one of those fuses! cheers again.

 

[Muttley]

Checking where those fuses are wired to is not always easy.

S177 is the Alternator, that's easy to see. S176 seems to be the main power feed to the cabin for instruments, inside lighting, air blower etc etc. No easy way to check for sure.

By poring over the wiring diagrams I think that S164, third from the left, is the radiator fan high power feed, as the red/black wire colouring matches the diagrams on the rad fan control and aircon system pages.

That leaves the last one, in the position for S163. The wiring diagrams show this leading to a red wire which feeds the glow plugs, so the annnotation in the books is misleading for the case when the fifth fuse is not fitted.

The wiring diagram for fuse S162 shows a red wire leading to a pair of relays controlling extra glowplugs set into the coolant flow, and used to heat up the coolant to operating temperature quickly. When they are fitted I think they show up on the righthand end of the head, so I'm pretty certain I don't have them. Whatever the manuals might say.

So 50A is correct for S163, but it feeds the cylinder glow plugs and not "engine management". S162 is missing on our cars, as is the associated system, the coolant heater (sounds odd doesn't it) which I guess is a cold-climate add-on for markets like Norway and Sweden.

 

[glynnd]

If its not blown remove it and see whats not working then
Glynn

 

[zygoma999]

cheers guys. i've ordered a 50a fuse - 2 quid from seat but 43p from vw!! might be the same for other parts aswell!
glynnd, the condition of this fuse is that bad that, if i touch it, it looks like it will disintegrate. so, i'll wait till i have my new one in my hand before removing this one. but, i will check what isn't working with it out!
cheers again guys!