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Help desperately needed with fuses!

25K views 39 replies 7 participants last post by  0049bri  
#1 ·
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Can anyone PLEASE tell me what the correct amps of each of these fuses are? It is the fuse box on the side of the battery. I can't read what is on them because they are so badly corroded. What I can see is that the one on the far left is 60A and the one on the far right is 110A. The others I can't make out. 2nd in from left might be a 40A.

I hope someone here can help. I've had no luck from frantic Googling, going to the garage, or ringing the dealership! And if someone knows what they are for then even better! I just know the van won't start and several of them are corroded.

Thanks, Jamie
 
#2 ·
Is there continuity across them? If current flows through them, they aren't the problem. Yet. Get a multimeter on it if you have one. Unbolt them and give it all a clean-up. Spray with WD40 and put it back together again. What engine is this? There are five of them and they are big, so I reckon they might be glow plug fuses, although I could be wrong.

Vulch
 
#18 ·
Just went back to start of thread....

@ Vulch...
Never EVER WD40!!!!

Water Dispersant, trial number 40 was for, as it says!
It's oil based, and oil is an insulator....possibly the WORST thing you want on electrical connections!

Leave it in the garden shed for the kids bikes and the lawn mower (or, possibly, to spray on the OUTSIDE of the distributor cap and plug leads of a petrol engine!)

The aerosol content of it also rots plastic....

Possibly the biggest mistake many people make with electrical systems. :eek:
 
#3 ·
Thanks. They are all badly corroded with 2 broken because of the corrosion, hence why I can't make out the correct amps for them. Regardless of what they are for I know that the circuit is broken so they need replaced. Engine is the 2.5tdi.

Someone must be able to pop their bonnet and check the amps for me?!
 
#4 ·
Looking at your picture, starting at the left (ignoring the blade fuses): 60A, 40A, 40A, 50A and 175A. Your one on the far right for the alternator doesn't look like 175A as it has cut outs. The 175A is fully rectangular. I know that one, more than any others to be right as I had to replace it following the jump leads going on backwards when I took it for a test drive.
 
#10 ·
It varies from van to van, spec to spec and year to year.

MINE has 80 amp (1st position) for glow plugs, then 2 x 50 amps for the fans.
NO fuse for the 120 amp alternator.
I had 2 spare slots.

Caravelle I scrapped had an extra fuse for the aircon....but can't remember where or what value.
 
#12 ·
As I said before, not 100% sure, but 1st fuse is for glowplugs, 2nd and 3rd are the radiator fans.

4th and 5th in MY van are empty (or were, I used one for some extra lights I fitted).

The 5th is used for the alternator IF it's fitted, I don't think the 120 or 150 amp units use a fuse.

Even the diagrams are confusing, as sometimes the fuses/wiring is shown dotted. (or with a * against them.)
 
#13 ·
thanks Gaz, here is my set-up (left to right)
60A - 40A - 40A - 50A - 175A

i.e. as mistergrumpy says.
wire colours should help in ID ing them and what they supply, I have made a note of this now and will try and trace later.
I also have 3 blade fuses rated (left to ruight) 30A - 30A - 5A cant see the exit wires for these though ? wonder what these are for ?
according to my PR sticker I have a 120A alternator.
 
#14 ·
OK, seeing as I'm in my "polite/helpful" mood, I went out (in -4C...say - "Thank You" !) and looked at mine.

Yes...60 amp is for glowplugs
2 x 40 amps are the radiator fans.
I installed a 50 amp in the 4th slot for my home brewed headlight upgrade loom. (Then feeds 2 x 20 amp fuses to relays.)
175 amp in the 5th slot for the 120 amp alternator. (I was wrong about that :* )

The 3 blade fuses have a connector block underneath them....but NO connections in it.
Maybe those are used for air con....someone else may know.

Most diagrams I've seen do not show a fuse for the alternator.....but it's certainly there!
 
#16 · (Edited)
Look/feel under the 3 blade fuses.
Mine has a "connector" plugged in, but there are no cables in it.....just an oblong box stuck below the fuses.
If you look at the OPs pic, you can see the 3 blade fuses, and the "empty" connector below it.

That 4th fuse could be for anything!
Any "extras" on your van that you know about?
It could even have been used for a split charge system.
Spotlights?

As I said, in mine, it was a vacant slot....and as the box has nice, thick wire to the battery, I used it to supply my extra front spots rather than yet another cable on the battery clamp.
I'm trying to think back 6-7 years now, but I "think" the 4th slot didn't even have a fuse in it until I bought one....same as the OPs pic.
 
#19 · (Edited)
Heated seats come from the internal fuse box....from the X lines (the one fed from a separate relay controlled from the ignition).
I'm saying this, as I have heated factory seats (never used them...even at -20!), but there was no fuse in that slot.....
They take about 8 amps each....so wouldn't need a 50 amp fuse.

Keep the ideas coming.....
Either I say "Yep...possible", or I "Shut you down in flames"...I:

Have you seen the response I got from this guy for trying to help?

http://www.vwt4forum.co.uk/showthread.php?t=1107242

OK.....I speak my mind....but my comments were exactly the same as I'm making to you. T:
 
#22 ·
I finally find out what the previous owner of my T4 did to her and what that 70amp diy inline fuse for.
182031

Looks like the alternator fuse was burnt with the socket in fuse holder, and he replaced it for inline maxi fuse 70A (for 105A alternator, lmao).
182032


It looks like there is a hole in the fuse holder where the bolt fore the eyelet should be, but not sure how it should look when it's new.
Is it easy fix with bolt+but and just connect the fuse and cable with eyelet like the other cables?
The new box costs at least 60 eur.

The old solution is working, but yesterday I had already second time blown fuse for past year. But this time it also melted a bit the fuse holder so now I should replace it. And that's a pain in the ass because it's just impossible to find maxi fuse inline holder in Norwegian offline "car parts stores". Need to order it, lol.
So I'm thinking to replace it temporary for AGU fuse (80A) but I'm not sure if it's a good idea because these fuses can work different (like slow melting, not instantly), stores don't have such information about how fast it will burn with different raise of amps.
Any thoughts about it?

Also, isn't the wire from 105A alternator too thin (first pic, red cable with black tape below the hand)?
 
#23 ·
Are you sure it's a 150A alternator?
AFAIK, they were only fitted to Multivans/Caravelles. (With Klima Aircon).
I have one as a spare in my garage from a 'velle that I scrapped.
Connection for that did NOT have a fuse, and the cable IS a lot bigger.

Maybe someone upgraded the alternator from a 90A, and so the fuse melted?!?!?!
My current (no pun intended) one is a 120A one.....again, connected direct to the battery, NO fuse.

Circuit diagrams in manuals show that there was no fuse for the bigger alternators.......
 
#24 ·
Not 150, I think it's 105A (if I remember correctly, it was replaced, but not sure)

Cable is definitely underrated, I checked the spot with a tape and it looks like added piece of cable is slightly smaller than original (black), which is stupid. I will change the whole cable for something bigger in the future. But now I need to fix fuse holder.
 
#25 ·
Standard ones are/were 90A, 120A, and then 150A.
Whatever, as far as I see, it was ONLY the 90 that had a fuse inline.

Btw, BLACK is the standard colour for the +ve cables....Brown (mud/soil) is for the "ground" (LOL) wiring.
Confused me for a while, as being red/brown/green colour-blind, I almost tried to fit a battery wrong way around!!!!!!
 
#27 ·
It's to prevent an explosion if the cable wore and shorted to the engine!
Nothing to do with protecting the alternator....if that goes faulty, it's FAULTY!
You'll notice the newer cables have thicker insulation.

ALL fuses (both vehicle and household/etc are there to protect the CABLE....NOT whatever is connected.
It's the one good thing about the big UK plugs....they have a fuse inside from 1 to 13 amps....that depends on the size of the cable. (And the cable should be sized to the power of what is connected!).

Vehicle electrics are a little different. as only having 12 volts to start with, dropping a volt or 2 makes a difference.
When you have 230 to play with, losing a few volts makes little difference.
That's why a car bulb that takes 5 amps, "should" have much thicker cable than a household 60 Watt lamp. (That takes 0.3 amps......)

Alternators are "voltage regulated, current controlled", so will never provide more current than is required.
After 1st starting, it may supply 50 amps for a SHORT time, then drop to around 10-20 to charge the battery.....
But add on 15 amps for the head/sidelights, another 5 -10 for blower, 20 or more for aircon, 10 for heated rear screen, plus etc, etc....it soon adds up.
If you have a split charge system, the leisure battery will also requir current (quite a lot if it dis-charged over night).
Hence the reason Multivans/'velles have a bigger alternator fitted.
Remember, 40 years ago, 20 amp dynamos were common, then came the (whole) 28 amp Lucas alternators....plenty to cope with demands at that time.
35Watt headlights....no aircon, no rear heaters, no electric windows, etc etc.
With modern/more electronics in cars...that simply went UP.
 
#28 ·
Found out that melted fuse box is quite a common problem, as described on t4-wiki.de (and also when I was searching used part, I could see some burning spots on used fuse box)
google translated:
The factory cable lugs are not always up to the requirements. In particular at the fuse connection for the alternator (far right in the picture) there were contact problems with various vehicles that could only be recognized externally by the fact that the cable lug heats up considerably during operation. In the worst case, this can cause the fuse box at the lower right corner to melt, making it unusable. A professionally pressed tubular cable lug (16mm², 6mm hole) from switchgear construction instead of the original provides a permanent remedy. To determine whether the respective vehicle is affected, let the engine idle and switch on as many electrical consumers as possible (high beam, air conditioning, blower, rear window heater, etc.). The cable lug must not heat up significantly.
 
#31 ·
Found a similar box on Aliexpress
Only ~10 eur (without blade fuse plug) vs ~70 eur for original (quite a price for the plastic box with 5 bolts, lol)

Also found a lot of topics with common problems, where you can find such boxes (Skoda, VW, Audi).
Best tip learned = check nuts and tighten them if they lose because that's the reason for melting the box and not the fuse.