Saturday, 10 February 2018

Solved battery problem

Very good session today, spoilt only by having to spend a maximum of 30 mins in the garage each time before coming in to thaw out.   Only outstanding problem was the battery draining overnight, so the first thing I did last Thursday was to get it tested at Halfords.  Passed with flying colours.   So there was obviously a current drain somewhere.   

When I took the battery out the tray was rusty and soaking wet, and the wiring was resting in it.  But when I wiped it the rust all came away and it cleaned up quite nicely.   I thought the water had come from the last time I filled her up, but when I looked closely I have a small leak in the washer bottle, so that wasn't helping.   I initially thought that was the reason for the current drain, but it turned out to be a red herring.    But glad I found it.

I'm the first to admit my wiring is 'ad-hoc' and really needs sorting out so I thought that might be the problem.   So I stripped all the diagnostic wiring out.
No, another red herring.
So then it was time to check the circuit.   By undoing the mounting of the isolation switch I was able to isolate the battery then bypass the switch by putting a multimeter across the terminals.   And Bingo, there was a 160ma drain.    That doesn't seem much, but in theory it should be zero, so needed investigating.

Now, I thought the only things that are live all the time are the 12V charging socket, which shouldn't take any current, the lights, the horn and the Voltmeter I had fitted, which should take zero current.   But then I realised that because the horn, the voltmeter and the oil pressure gauge are on the same panel, I had also wired the oil pressure gauge to be permanently live as well and I had no idea what the current drain on that was.    So I unplugged that and the drain dropped to 60ma, so that was a help.  Then just to check I unplugged the voltmeter and the current drain dropped to zero.   So my voltmeter does take a current drain of 60ma (cheap off E-Bay from China so shouldn't really be surprised).   
So both rewired to become active only with the ignition.

I then wondered if that was why my previous battery had started losing charge.   Luckily I hadn't taken it to the tip so for the time being I have put that back in to see if it holds charge.   I'll know tomorrow afternoon.

So everything replaced, with a cloth underneath the washer bottle as a temporary measure.   And the wiring tied up.   And extra insulation added to the positive terminal of the battery just to make sure.

Tuesday, 6 February 2018

Repaired Bonnet

Picked up the bonnet today.   It wasn't cheap, but they have done a very good job on it (2 man hrs work apparently).   They have shaped it correctly so it sits square and all 4 catches lock very positively.   They have knocked out the dents but were unable to get a perfect finish, so I have an area about 10" x 6" that is 'dimpled'.   His advice if I was worried about it (which I'm not) was to put two 9" strips of 'sticky backed plastic' either side of the bonnet as 'go faster stripes', either carbon fibre lookalike or blue to match the rest of the car.  That would hide the damaged area.  These would be on the bend of the bonnet, leaving the central part with the louvers untouched.  I'll take that under advisement.

And I have also riveted in a replacement louvre as the previous one was destroyed.


So that just leaves the nose cone, but I am going to wait for the weather to warm up before I tackle that, as it is perfectly serviceable as it stands.

And I now need to figure out why the battery is suddenly draining overnight.  I recall knocking off the protective sleeve on the positive terminal while I was playing around shaping the bonnet so I could have shorted it and trashed the battery. (There is only a few mm clearance between the terminal and the bonnet).  Or I might have damaged some of the wiring that runs down the sill.   So I am charging the battery up off the car and will get it tested on Thursday and if it has failed catastrophically I'll get a new one.   If not I need to trace the residual leak.