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snattrass

Headlight booster circuit overheating/messing up headlights!

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Last night after dark during a spirited country lane rally, not for the first time, my headlights suddenly went out leaving me with just the moon and my sidelights for illumination which, after getting home, regardless of repeated attempts to switch off, even after turning off the ignition, stubbornly refused to go out. Only with the engine idling and the stereo switched off did I finally manage to get the sidelights to switch off.

 

 

Sometime later in the small hours [after answering a call of nature] I noticed that the sidelights had [again not for the first time] "magically" come back on. This time I was only able to turn the sidelights off by running the engine after first eliminating the aftermarket headlights boosting circuit [fitted by a previous owner]. As expected, the wiring on the boosting circuit was extremely hot and the [20A] fuse that I removed from the booster circuit was so hot that it had been melting the see-through plastic housing at the top of the fuse, not surprising after the previous fuse that I replaced had pretty much completely disintegrated.

 

 

I know my lights swtiches are working fine as I replaced them a while ago [unless the booster circuit has damaged them by pushing too much current through them - but that would surely cause the fuses to break] so, unless anyone can advise me of a better plan, I plan to remove the booster circuit, which is basically a fuse, a relay and a few connecting wires, and install a new booster - recommendations appreciated!

 

 

Any thoughts / ideas? Common / similar experiences. Solutions / suggestions?

 

 

Thank you, Simon.

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Sounds like a crap uprated loom, buy or make a better one, cut the old crap out and replace, taking care to insulate everything properly.

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If i was you i'de remove the existing headlight loom and replace with a decent quality one.

If i had to guess, without looking at the harness, then i would say it's either wired up to the relay incorrectly, the relay is faulty or the wire that has been used in the harness is not of the correct guage.

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Thank guys.

 

nice to see u Tom! I got it nicely lowered now thanks for your help / advice. I'll post some pics sometime soon.

 

Any recommendation for a decent lights booster / links?

 

Just had a look at others similar problems with these devices. It seems a lot of people who have fitted them have been having similar problems as i have been having. Also it seems that moisture can also be a cause of problems and I just pressure washed my engine bay too so that will not have helped.

 

 

In any case it seems like mine is inferior quality and only has a single relay compared with others i've been reading up about which seem more sophisticated.

 

cheer, S

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OK I have now replaced the old crappy headlight loom with one I made myself along the lines of that laid out by DavidWort in his excellent project notes.

 

BUT, after I finished it and turned on the main beam it blew the 15A fuse (and a replacement) I used from the battery to the relay. Further to fitting a 20A fuse it seems to be holding OK now, but I am concerned that it should need a 20A fuse when 15A should be adequate - can anyone help? I cant understand it! Could moisture be a factor (it was raining when I was fitting it)?

 

Also I noticed that since doing the job the passenger side dipped beam is brighter than the drivers side dipped beam! Is this because I have positioned the 2 twin output relays I have used (1 for main, 1 for dipped) on the passenger side right behind the passenger lights causing voltage drop to occur along the wires that tranverse the radiator to the drivers lights? Doesnt seem like there should be any appreciable difference over such a short distance ( I have used 30A rated wire). Or could it just be that the drivers headlight bulb is not so new and I just never noticed the difference before? There is a definite difference!

 

Makes me wonder whether I should have used 4 seperate relays instead of the 2 twin output relays I have used.

 

Cheers, Simon

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What watts are your bulbs, and which lamps did you wire into your uprated loom?

Don't forget main beam on the Corrado is 2*60W plus 2*55W, which works out at about 19 Amps..

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Pass me the "Dunce Hat"! How stupid of me!

 

 

Of course dr_mat u r so right - 2*60W plus 2*55W works out at just over 19A!!!! I orignally intended to use a 4 relay design with 4*15A fuses but then decided to just use 2 30A rated relays, one for main and one for dip but in my haste forgot to work out the new fuse ratings. Using 4 relays, 4*15A fuses is all that is needed, but of course, using 2 relays, as you say, the current comes out at just under the 20A fuse for the main beam and for dip at just under 10A (2*55W/12V = 9.16 amps)!! I will now also try a 10A for the dip instead of the 15A I currently have. If I upgraded main beam to 100W it looks like I would need to go to a 30A fuse (2*100W plus 2*55W /12). Can u recommend a suitable legal wattage / decent brand bulb to go with my new loom? Are these blue tint bulbs any good or more for show?

 

 

Off to take voltage readings to see if there is any power drop on the drivers side to account for the brighter passenger side dip!

 

 

Cheers dr_mat, S

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Voltage was the same both sides (thankfully)!

 

 

Purchased 2 Halfords Zenon 90% brightness improvement and both sides are the same brightness now and nice and bright too!

 

 

Thank you for help everyone. Si

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