Dead battery now keeps blowing fuses

[Ruud]

I really hope someone can help me here.

1998 Ls400 Battery went dead over night. rear passenger door not closed fully so interior light must have stayed on.

Connected a fully charged Battery and now it keeps blowing fuse ECU-B, Radio NO1, CRT and ETCS.

Has to be a short somewhere I reckon.....

[Cotswold Pete]

If you take the fuse out and the measure resistance between the fuse terminal and the chassis, it reads zero implies a short to earth.

If not then it could something just drawing a shed load of current, which could be the ECU of radio.  But as to what is was if it was the ECU or radio,would mean disconnecting them (one at a time), to find out the culprit.

In my earlier Mk2, I used to find the fuse that deals with the cigarette lighter would blow if I had the lighter socket  in use with the steering on full lock as the time I started up the engine.  Never got to  the bottom of that one, just made sure I never left car in full lock when turning off the engine.

[Ruud]

I really wonder why it is blowing 4 fuses at the same time from just   the Battery going flat. It was running perfectly with no electrical issues whatsoever.

Makes no sense to me at all............

[Cotswold Pete]

25 minutes ago, Ruud said:

I really wonder why it is blowing 4 fuses at the same time from just   the battery going flat. It was running perfectly with no electrical issues whatsoever.

Makes no sense to me at all............

Does make no real sense, it would be as if all the live side had shorted, and for 4 to do it seems odd.  Any chance you can see by taking out all 4 fuses whether the 4 lives have all found a common connection.  Other than that not at all sure without having access to a wiring loom diagram.

Not sure if it would work where you take out the four fuses, then turn on ignition and insert fuses one at a time.  Someone else might know whether this is likely to create more mayhem or not.  I have had a few flat batteries over the years and never had a 'weird' problem like this.

 

[Ruud]

Solved.

I'm very ashamed to be typing this, but the Battery charger / booster was hooked up the wrong way and I never checked. My neighbour has a professional charger / booster and hooked it up the wrong way. There is a thick red wire going from the VVTi actuator to the negative side of the Battery so this was confusing.

Even with the Battery charger disconnected, the fuses would still blow. Turned out the Battery had taken a reverse charge.

Fitted a new Battery and replaced all blown fuses (7 in engine bay incl the 120amp alternator fuse and 6 under dash) It is working all fine now 

[Chris Skelton]

....and the moral of this story is.....Be careful out there/PAY ATTENTION! Don't rush things.

 

easy to do though, I guess.

[steve2006]

I only read the first 3 posts and immediately thought reverse polarity Battery connection, even got the OEM wiring manual out to see where the fuses are powered to and from, saved me looking through over 400 pages.

[Verbout]

Oh dear. 

[mikeyv]

17 hours ago, Ruud said:

Solved.

I'm very ashamed to be typing this, but the battery charger / booster was hooked up the wrong way and I never checked. My neighbour has a professional charger / booster and hooked it up the wrong way. There is a thick red wire going from the VVTi actuator to the negative side of the battery so this was confusing.

Even with the battery charger disconnected, the fuses would still blow. Turned out the battery had taken a reverse charge.

Fitted a new battery and replaced all blown fuses (7 in engine bay incl the 120amp alternator fuse and 6 under dash) It is working all fine now 

Good on you for owning up.

[Cotswold Pete]

Glad it is sorted, never thought of reverse polarity.

I  always take my Battery out to charge, and being an trained in electrics, always double - double check polarity, as in the old days when I played around with valves, 400v reverse polarity creates some interesting pops and bangs.