Several seconds is quite long enough, and if there IS a spark, I've never seen it.

 

per the posting 120 seconds. you are just touching two cables both disconnected from the battery so no spark

 

sorry im being thick again but this is just removing the negative cable, not joining the 2 together. Really interested to know why the difference, which is right or do both achieve the same thing?

 

Modules contain capacitors, capacitors hold electrons.
Disconnecting a battery will cause capacitors to slowly discharge, resetting volatile memory........ eventually.
Shorting a positive lead to ground will actively discharge capacitors, resetting volatile memory, but this will happen nearly instantly.

Therefore, EITHER disconnect the battery for many minutes, or touch the two DISCONNECTED battery leads, the Positive Lead and the Negative Lead, together for a few seconds.
MAKE SURE there is NO connection between the battery's + and - posts!

 

Got it, very much appreciate the patience and the informed answer. Thank you

 

I haven't seen a spark, but I did this a couple of weeks ago and heard what sounded like a spark, more like popping a breaker actually. Since then, my TPMS warning has gone away and not come on again.

 

Took some time on a gorgeous fall afternoon to refinish the headlights.
Wet sanded with 2500 then used the 'rag and spar varnish' technique to recoat them. I'm very pleased with the results.

Before


After

 

1. A few (10) seconds
2. No, unless you forgot to disconnect at least one of the cables from its respective battery terminal💥🙀

 

Do you flat off the outside of the lense I presume? Ive not taken one apart so don't know if it comes apart.

 

Had winter tyres and (newly ceramic sealed) Vulcans fitted, just in time as 4c outside.

As they took my Summer vortex's off I asked for 2 mins with the wheel oft to clean shocks and arms with g101 cleaner, then sprayed everything with bilt hamber atom-mac.

Will take a few miles to break in new tyres but could tell the difference in rhe 2 mile drive back with 8mm of tread. Oh, winter tyres running 3psi higher due to softer compound

 

I'm not sure I follow the logic. More pressure than recommended (over inflation) will still still mean that the tyre is running more on the central part than it is designed for regardless of rubber characteristics, resulting in less rubber on the road and faster central tyre wear. Does your handbook/door plate suggest to use more pressure for winter tyres? I don't remember seeing such a recommendation in the 25 years I have been using winter tyres.

 

wsn03, sorry I don't understand your question.

"England and America are two countries separated by the same langauge."
Attributed to G.B. Shaw

 

I refinished the outer lense on the car. No disassembly.

 

technically he didn't say overinflate, he just said 3psi relative to his usual figure. both figures could be just below spec.

since winter tires are both a slightly softer compound and the tread is cut taller (and a little differently), overinflating in theory should put back a tiny bit of the mechanical grip that you very reasonably give up when you go from summer to winter tires, and only in the center band as you've stated. but of course that's holding all else equal, which means, both tires he uses would have to be rated the same, and the same size exactly, and so on: i'm not sure you would be able to just add pressure to a totally different radius/aspect/etc. tire and get any effect out of it. but you might experiment until you do observe one, and then decide on 3psi or so to reproduce it regularly.

and you're right that no manual would ever recommend it, but then, plenty of manuals are written by the lawyers instead of the engineers.

 

Thank you. Mine seem to be perfect, but its really interesting to know I can use 2500 on glass like that - every day's a school day

 

Ha!
Sorry - in plain speak I'm asking if he does the inside or outside of the glass unit with his wet and dry 2500 grade (if that makes sense)

 

A

 

outside.

 

Getting to the inside of the headlight cover (which is plastic) is a little more complicated.

I've not done this myself, but I understand you need to remove the headlight assembly and then separate the cover from the headlight body. There is a butyl rubber sealant holding the two pieces together and this needs to be heated in an oven or other enclosed space using a heat source (heat gun, e.g.) to be pliable enough. There are also spring clips that need to be removed. Some care is required in these steps. Overheating the plastic parts can cause melting and the butyl rubber can mar the surface of the bright parts in the headlight itself. On reassembly you need to add some butyl rubber to make up for that lost in disassembly, clamp cover and headlight together and reheat to ensure a tight and complete bond.

Others here have done this work but I did not find a good thread to link to. However, this is a very detailed video that I think is helpful.


Once you have the cover separated, you can work on the inside in the same way you would work on the outside (several threads here on this) but of course you don't need to coat the inside with an anti-UV coating.