GENERAL
De-icer
Q Thank you for your article on glass cleaners in the March 2022 edition of Car Mechanics. Very informative. I have had problems with a de-icer – it seems every one that I have used keeps foaming up. I have tried several makes and it seems to be happening with all of them.
Can you please tell me if you have done any research on de-icers or are going to in the near future? George Vincent
A Looking back, it seems we have not carried out a product test on de-icers for many years. This is something we will consider.
I suspect that the de-icer manufactures do encourage the foaming of the product to save the amount of de-icer needed to cover an area.
By allowing the product to foam this gives a greater area to the same amount of liquid.
GENERAL
Jump pack
Q I have a little lithium jumpstart pack that has worked well in the past but on the last attempt has failed to start the engine. I scratched my head a bit wondering what had changed and came to the conclusion that the vehicle battery was flatter than previous times (no ignition lights) and had sucked all the charge from the lithium pack before it had chance to start the engine.
To work around this situation, I considered lifting the floor panel (Ducato) and connecting directly to the starter battery (with the vehicle earth disconnected) to give full power for starting.
A problem might arise with this method as the earth would need to be reconnected to the battery negative with the engine running (as it would still be flat and couldn’t start the engine).
Can you see any potential problems with this method (damage to electronics etc)?
Ian Pedley
A I have in the past encountered a problem where the vehicle battery was so flat that it was sucking the life out of the jump pack, and by disconnecting the battery and using the jump pack directly, I was able to start the vehicle. This was however quite a few years ago and things have moved forward, and not always in a positive way.
Connecting the battery once the engine has been started may cause a problem with a sudden surge of current, and this could cause problems. For this reason, I would not now consider it.
Another very possible scenario is that the lithium jump pack will not operate without being connected to the battery, most have a smart circuit and will know if battery voltage is present and without this will not power-up.
One possible solution to a continually draining battery may be to connect a solar trickle charger – this may maintain enough power in the battery to prevent the same situation occurring again.
GENERAL
Headlamp bulb upgrade
Q I’ve been struggling lately with night-time vision on wet and unlit roads and so I looked into upgraded bulbs. I have found that many of the leading bulb manufacturers are offering legal 55-watt bulbs that they claim are up to 150% or brighter and further illuminating than standard bulbs.
Do you have any experience or endorsements of any of these from anyone that you know?
Dean Savage
A Although CM covered the topic of bulb legalities in the May 2016 edition, we have not done a headlamp bulb comparison test. I would start by saying that ensuring the headlamp lens is clean and has not become opaque would be the first point to check. This can cause light output problems.
The Road Vehicles Lighting Regulations 1989 do not actually specify the maximum wattage of a vehicle headlamp bulb but the bulb does need to meet the EEC regulations which state that the luminous intensity of all the switchable high-beam headlamps must not exceed 300,000 Candela.
There is often a confusion around how one 55W bulb can be brighter than another, and it is said that this is achieved by a more accurate placing of the filament. It has been said that a thinner filament is used to create a brighter light, but as the size of the filament is also covered by legislation, this should not be the case. A thinner filament would of course mean that the bulb had a shorter life due to its higher running temperature.
Tests have been carried out by different bodies and from looking through the results from a range of tests, it would appear that a compromise is made between the beam length and the beam spread. The same amount of light can in effect be used
