Electrical problem - any thoughts?

[Scribe]

Herbie, by 'Battery clamp' do you mean the screw connection to the terminals on the top of the Battery?

[Herbie]

This is what I mean. If you tighten that nut too much then the post can become disconnected from the plate inside the Battery case:

[Scribe]

Mine are screwed onto the Battery terminals by a wing-nut rather than the bolt and nut like in your picture, and the idea is that they're simpler to undo - you don't need a spanner.  But they are very tight - more than finger-tight, in fact.  Could that have the same effect?  

[Herbie]

3 hours ago, Scribe said:

Mine are screwed onto the battery terminals by a wing-nut rather than the bolt and nut like in your picture, and the idea is that they're simpler to undo - you don't need a spanner.  But they are very tight - more than finger-tight, in fact.  Could that have the same effect?  

I don't know to be honest, it was just something to look at and be aware of.

[ColinBarber]

4 hours ago, Scribe said:

But they are very tight - more than finger-tight, in fact.  Could that have the same effect?  

Probably not, damaged is caused with a normal nut and bolt where someone with a socket wrench over does it. 

How is the lead connecting to the Battery clamp? Can you take a picture?

[Scribe]

Battery hasn't been reconnected after its charge, but you can see the wingnuts that screw onto the top of the terminals when the leads are in place.  The idea is you don't have to touch the nut and bolt gripping the terminal itself.

[Scribe]

Is this the problem?  It could account for the intermittent failure of connection.  I'm assuming a new pair of leads will cure the problem, though the positive one seems complete and undamaged.  Anyone know how long the cables need to be?  They're sold in different lengths.  And what do they connect to at the other end?  They have a ring at the other end too.

[Moleman]

5 minutes ago, Scribe said:

Is this the problem?  It could account for the intermittent failure of connection.  I'm assuming a new pair of leads will cure the problem, though the positive one seems complete and undamaged.  Anyone know how long the cables need to be?  They're sold in different lengths.  And what do they connect to at the other end?  They have a ring at the other end too.

That really looks like that could be the issue.

[Scribe]

Even if it isn't, it surely needs sorting!

[Scribe]

Simon and Herbie, looks like you were right with your first comments.  Garage thinks the problem was the earth connection from the negative cable.  They've added an additional one for security, attached to a different part of the Battery terminal, which should be fail-safe - though I won't know for sure until I've used the car for a while.  Alternative long-term solution is to change the cabling to the fusebox and something else (sorry, the mechanic got a bit too technical for me).  All seems well for now.

[Tinonline]

2 hours ago, Scribe said:

Simon and Herbie, looks like you were right with your first comments.  Garage thinks the problem was the earth connection from the negative cable.  They've added an additional one for security, attached to a different part of the battery terminal, which should be fail-safe - though I won't know for sure until I've used the car for a while.  Alternative long-term solution is to change the cabling to the fusebox and something else (sorry, the mechanic got a bit too technical for me).  All seems well for now.

Well I’m glad it looks as though it’s sorted. Very belt and braces adding extra earth…a complete new Battery Earth cable will do it unless…it will be fine now.👍

[Scribe]

The invoice says: Remove Battery and tray to check earth strap routing.  Found it goes back to fuse box.  It would require some stripping out work of fuse box to add a new earth strap.  Added additional earth strap from Battery to body earth point - customer to monitor.

So this is a temporary measure really.  All was well when I took the car out on Saturday, so I need to book it in to have the work done properly.  Apart from anything else, it will tidy up the terminals and make disconnecting the Battery easier.

[Herbie]

1 hour ago, Scribe said:

The invoice says: Remove battery and tray to check earth strap routing.  Found it goes back to fuse box.  It would require some stripping out work of fuse box to add a new earth strap.

Hmm.....

I've never known an earth strap to go to the fuse box, there's just no need for it.

[Tinonline]

2 hours ago, Herbie said:

Hmm.....

I've never known an earth strap to go to the fuse box, there's just no need for it.

Yes I thought it went straight to the chassis. 🧐

[ROYT]

Here is my 2cents worth

Fit new Battery cable ends, deleting the wing nuts.

Remove all chassis earths, clean them and the metal where they are attached

Any earths to the engine do the same.

Look at high amp fuses for corrosion or bad connections

Look everywhere for signs of powdery green corrosion

If everything goes completely off it's likely to be the main thick cables.

When it's running OK,  wiggle the thick cables and any you think suspect

to check for an intermittent break or poor connection

 

 

[Scribe]

Thanks Roy.  After using the car last Saturday (it behaved faultlessly) I put it back in the garage, but on Tuesday morning the connection had gone again, so I'm back to square one.  Obviously, the connection doesn't always fail because of movement - it's done this once before, while the car was parked on the driveway for a few days.  It's booked in to the mechanic next week, and I'll give him your suggestions.

I'm trying not to feel too bad about this, because the car's still so good to drive when it's working, but I'm getting a bit fed up.  It must be something simple, because when the connection's there everything works perfectly and the car drives like a dream.  Gets some stares in the Tesco car park, too.

[Tinonline]

6 hours ago, Scribe said:

Thanks Roy.  After using the car last Saturday (it behaved faultlessly) I put it back in the garage, but on Tuesday morning the connection had gone again, so I'm back to square one.  Obviously, the connection doesn't always fail because of movement - it's done this once before, while the car was parked on the driveway for a few days.  It's booked in to the mechanic next week, and I'll give him your suggestions.

I'm trying not to feel too bad about this, because the car's still so good to drive when it's working, but I'm getting a bit fed up.  It must be something simple, because when the connection's there everything works perfectly and the car drives like a dream.  Gets some stares in the Tesco car park, too.

Ok now I’m feeling very annoyed for you.

My opinion and feeling is, you have to NOT give the car back to your regular garage or mechanics that have not been able to resolve your issue to date. 

Maybe a mobile auto electrician or just a different garage: not an easy choice.

I am concerned about the rat smell you had a while back…so you need to mention that so the unexpected is taken into account.

Agree this is fixable…just a pain getting to it.

[Herbie]

At this point you need to specialise - aircon specialist for aircon problems; mechanics for general mechanical problems and in your case, auto electricians for electrical problems.

[Scribe]

That makes sense but my options are limited.  There's no auto electrician in the area, certainly not a mobile one.

My usual mechanic (Toyota/Lexus trained), who's always looked after the car, is very busy, which is why I recently went somewhere else (also Toyota/Lexus trained) for the Battery cables issue.  The car's booked into there again on Friday as my usual mechanic is away at the mo.  As there has been nothing left switched on (I've checked the boot light goes off) they think there must be a drain that completely flattens the Battery in 2-3 days, as this has happened before.  Whether it's related to the recent connection issue is another question.

When my usual mechanic last had the car in, he confirmed the Battery (less than two years old) was taking charge as it should, so he doesn't think it's the problem.  And I wouldn't expect a Battery to go completely dead in 2-3 days even if a boot light was on.  The Friday garage suggest trying to charge the Battery but not on trickle (which never does anything, maybe because the current's trickling out as fast as it goes in?) or jump-start, i.e. on the medium charge.  Is it true I don't need to disconnect the Battery if it's not on jump start?  I don't want to fry anything.  If this works and I can get the car to the garage on Friday they'll check the circuits for a drain.  I don't know what else I can do.

[Scribe]

'If you think you have a parasitic drain, a mechanic can easily diagnose this by performing a parasitic current draw test.'

Let's hope so.  And I'll mention the rat!

[Herbie]

3 hours ago, Scribe said:

That makes sense but my options are limited.  There's no auto electrician in the area, certainly not a mobile one.

Then get your wife/brother/friend/whoever to follow you out of the area to an auto electrician where you can leave the car with them.

'Auto electrician' is a proper trade in itself and it's becoming patently obvious that the people you're going to are not auto electricians.

3 hours ago, Scribe said:

they think there must be a drain that completely flattens the battery in 2-3 days, as this has happened before. [...] I can get the car to the garage on Friday they'll check the circuits for a drain.

Back on October 12th both Supafly and myself posted videos showing how to do parasitic drain tests. The thing is, even if your garage does find a parasitic draw, they then have to start looking for the cause of that draw and rectify the problem and again, this is where a proper auto electrician will have the proper tools, knowledge and expertise to get it done quickly and efficiently.

[Malc1]

finding a competent and useful Proper AutoElectrics person is very very challenging  .  I had this problem a while ago locally and each i approached , by phone tho'. was just PATHETIC  ............. then the issues vanished .  as they can so do on our Ls400s ...............  thankfully

Best wishes with your problem

Malc

 

[Scribe]

The problem has been: when all power was likely to cut out without warning, leaving the car without lights, indicators, electric windows etc., I refused to drive it further than necessary.  It's nerve-wracking, driving as slowly as possible in case there's the dreaded 'beep' and everything dies on you.  What happens if there's nowhere to pull over safely?  My normal Lexus mechanic is 7 miles away, the one I've been using recently half that distance, and I'm always relieved when I make it there.  There are garages nearer than that but they're not Lexus specialists.

Herbie, you kindly listed some auto-electricians for me, but some of them turn out to be 'normal' mechanics who don't actually specialise in electrics.  None of them answers the phone.  One of them is about 35 miles away, and I don't feel comfortable driving the car up the motorway that distance.  So no, the places I'm going to aren't specialist auto electricians - because I'm having the problem Malc had.

[Herbie]

Well, I can see what you mean but there's no getting away from the fact that a 'general mechanic' will cover electrics as one module of an HNC/HND/NVQ/whatever or one part of their training, whereas an auto electrician specialises from start to finish in that one thing. There's just no substitute for knowledge and expertise in a given field.

However:

7 minutes ago, Scribe said:

My normal Lexus mechanic is 7 miles away, the one I've been using recently half that distance, and I'm always relieved when I make it there.  There are garages nearer than that but they're not Lexus specialists.

At the very least, try one of the other garages.

It may be a Lexus but it's just 'a car' with wires and cables and a Battery, just like any other car from any manufacturer - there is nothing Lexus-specific about this type of problem and they may just have someone on the payroll with a greater understanding of auto electrics than your normal places.

[Scribe]

There may be no substitute for knowledge and expertise in a given field, but you have to be able to access it.  And I imagine most garages will claim to be competent in car electronics - that's why it's so difficult to find one who's actually a specialist.  Meanwhile I thought I was doing the right thing by going to a Lexus specialist, but maybe I shouldn't bother.  As you say, it's just a car.