Fuse Blowing Hell!

[Jesse16v]

Ive just about had enough lol ive posted more topics in this section than on any other forum.

My Valvers engine fuses keep blowing and i have no idea why, im thinking water is getting in to something, maybe wires under the car? im talking about the 25amp fuse 5 rows down in the fuse box.

Sometimes the fuse will hold out, the car will start but then i get down the road then the car stalls, then i check the fuses and that same fuse has blown again.

When the weather is hot and dry, i dont seem to have this problem? the scuttle area is completely protected from the rain

 

[bmh.01]

Got a multimeter? Can you test from the fuse terminals to ground and see what resistance you get.

 

[ben_p]

maybe its shorting out? loose wire?

 

[Jesse16v]

Yeah i got a multimeter but im no expert with it, do i need to put it on amps and put red pin in the fuse hole and black pin on the bodywork?

 

[bmh.01]

ohms and polarity won't matter but one pin in the fuse holder and one on a proper ground ideally. Needs to be unpainted metal or a bolt head etc. Do both sides of the fuse holder.

 

[Jesse16v]

Hi, right ive stuck the multimeter on the fuse holder, on the 2000ohms bit on the meter.

And one side reads 1 and the otherside fluctuates between -430 -107 & -380 when wiggling it about. ?

 

[bmh.01]

Swapping the probes round makes it read positive right? Did you get the same readings for both of the fuse terminals?

Its shorting to ground somewhere by the sounds of it anyway.

 

[Jesse16v]

I didnt check but knowing my luck ive got them round the wrong way lol. But only one of the terminals would read 1 and the other terminal next to it read the 430,107 and 380...but it was going up and down like it couldnt choose a number.

If it is shorting out somewhere is there any suggestions you have?

 

[gaz_5103]

follow the wire down the car and find where its shorting.

 

[bmh.01]

Right thats fine, the terminal that read 1 is reading overrange for the meter which means that ones fine. The one thats dancing about is where your earth fault is and i'm guessing it a cheap meter that'll be why its jumping around as its pushing the limits of it.

Without a set of decent wiring diagrams it'll be difficult to follow but you need to trace the wiring to find the fault, with a wandering resistance and one that high i'll put money on it being water ingress somewhere.

Never had a Mk1 so I can't really suggest where to look, this in the engine bay fuse box? (if they have one) or the interior one?

 

[Jesse16v]

Yeah this is in the Engine Bay fusebox, to be honest i only paid a fiver for the multimeter so thats probably why yes lol.

Is there anyway this could be related to the lambda sensor wiring underneath the car?


Here is where the fusebox is located on the valver:

 

[Jesse16v]

such as this? although it hasnt done it before

 

[bmh.01]

Why is there a problem with the lambda wiring? Its possibly powering the lambda heater circuit yes.

 

[Jesse16v]

This is so frustrating, i got it running for 10 minutres last night then the fuse blew again, there has to be something shorting it out in the engine area