Headlights dodgy connection

alinton · Post by **alinton** » Tue Dec 29, 2015 6:05 pm

This is annoying, sometimes when I switch on the heads, one doesn't come on. If I lift the bonnet and barely touch the back, it comes on.

So it's a dodgy connection, but I've not been able to work out exactly what it is, as every time I try to find it, once the light is on I can't make it go off.

Anyone else had this? Any tips?

Ta

A.

nitin_s1 · Post by **nitin_s1** » Tue Dec 29, 2015 6:09 pm

This is happening to my car too..

The passenger side headlight doesn't turn on, but as soon I give it a tiny push on the connector it comes on and doesn't go off..

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Tue Dec 29, 2015 6:46 pm

Quite common on 4g's - every single one I've had has done this.
It's just caused by standard car electrical gremlin stuff.
Clean up the terminals in the plug properly and the back of the bulb.
You can open up the back of the plug (small clip either side, then back hinges open) to pull out the terminals. Check that the wiring isn't stiff/suffering from heat etc. and that the terminals engage tightly with the bulb (i.e. aren't spread too wide apart) if they are then close them up slightly with a pair of pliers.
If you do pull the terminals out, be careful you put them back in the right holes in the plug, otherwise you'll end up with them not working, or bulbs being on main when they should be on dipped etc.

Post by **vanzep** » Wed Dec 30, 2015 10:15 am

like others have said its a common problem and normally traced to poor connection in the connector plug itself due to corrosion or overheating - these connectors dont like higher rated bulbs than 55/60w
once you get this problem your best to buy a replacement connector off ebay - ive seen waterproof ones listed as well. They are only a couple of quid
when i asked Honda about replacement connector they said i would have to buy the loom that had the connector on it and the loom was sold in pairs

alinton · Post by **alinton** » Fri Jan 08, 2016 1:02 pm

Why is the OTHER connection on the H4 lamps not used in the dip beam lights then? Are they dual filament lamps, the other one being meant for main beam maybe?

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Fri Jan 08, 2016 1:44 pm

alinton wrote:Are they dual filament lamps, the other one being meant for main beam maybe?

Exactly that

alinton · Post by **alinton** » Fri Jan 08, 2016 1:45 pm

Ah. I now wonder what would happen if I pressed them into service?

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Fri Jan 08, 2016 1:51 pm

If you use the main beam filament for dipped, the beam pattern is all wrong.
You'll blind other drivers and fail the mot - hence my note in my original post, re: reconnecting the connectors to the right terminals.

If you put extra wires from the (current) main beam bulb onto the extra filament on the other bulb (so you have both wired up to light up with the main beam) then in theory you'll get more light. However, if you simply wire across from the current main beam bulb to the other, you'll either overload the existing wiring and switch (burning them out) and/or also get less actual output from each individual bulb (due to the increased resistance of the circuit, if you've wired them in series...).

If you want to double up the main beams, you will need to make sure you wire them in parallel and add in an additional relay on the circuit (to feed the bulbs direct from a supply off the battery, with the old switch/wiring just feeding the new relay).