5 replies to this topic

[JamesAHolden]

Hi all,

 

I've got a '98 JDM mini (so SPI with AC if that matters) that has been blowing the leftmost 30A fuses in the engine bay.  It seems to be random, the car will drive for a while fine, then it'll blow two fuses in quick succession.

Initially I thought it was related to reverse (first few fuses blew when reversing) so I've looked under the carpet for the reverse switch wiring and seems fine but still blowing fuses, last few when just driving normally.

 

Read a suggestion to check behind the radio at the loom there, found some old tape that had hardened, exposing some wire connections, which I replaced, still blowing fuses. 

 

Someone on this forum suggested checking the loom behind the air filter.  So I've found a damaged wire that leads to the lambda sensor, seemed like the air filter metal had rubbed the insulation away completely.  I've wrapped the wire until my mechanic can replace it (I took a photo but can't figure out how to upload it here).

So my question is, have I found the culprit?  Is that wire likely to blow the leftmost fuse in the engine bay?  As far as I can tell the left most fuse is for the passenger compartment fuse box

 

I know the easiest way is to drive it and check if it still blows fuses, but I've use all the fuses at all the local automotive stores!  I only have 2 left.
 

Cheers,

 

James
 

[sonscar]

Look under the floor at the reverse switch wiring.Contact with the exhaust is not unknown,Steve..

[viz139]

Fuse 1 feeds the Passenger compartment fusebox.  If the fault was in the reverse lights or stereo it would blow the smaller fuse in the passenger compartment fusebox. Your fault is most likely a damaged brown cable earthing off something metal between the two fuseboxes. The lambda sensor is feed from fuse 4.

[Quinlan minor]

I had an issue on one of mine, where the loom had rubbed through on the clutch master cylinder reservoir. Intermittent cutouts on acceleration before finally blowing the fuse.

[JamesAHolden]

Thanks for the replies everyone, I've been told by my local mini club that J-spec minis with aircon had the engine bay fuses installed backwards, so fuse 1 is fuse 4, which would feed the lambda sensor.  I'll have a look for some brown wires worn through as well though. Thanks.

[68+86auto]

You can use a light bulb to limit the current for testing. Instead of the fuse blowing, the bulb will illuminate. A headlight is probably best for your issue assuming it's a short circuit somewhere. The bulb will glow when the load exceeds it's wattage. You can move the wiring around etc to try and replicate the short.

 

Thanks for the replies everyone, I've been told by my local mini club that J-spec minis with aircon had the engine bay fuses installed backwards, so fuse 1 is fuse 4, which would feed the lambda sensor.  I'll have a look for some brown wires worn through as well though. Thanks.

 

I've never heard of this fuse backwards thing, I'd question it.

Edited by 68+86auto, 17 January 2025 - 05:09 AM.