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HID Conversion with check control

Posted: Sat Jan 20, 2007 5:22 pm
by gazebo
Hi, I'm new to the forum but a long term owner of a 1986 325 Cab.

I've just test fitted a HID conversion kit and experienced a couple of problems. With the ignition on and only the side lights switched on the HIDs flicker. I think this is caused by having Dim Dip headlights as, when the Dim Dip plugs are disconnected, the problem goes away. Has anyone else experienced this and is my "fix" sensible?

The second problem is that the Check Control system shows a dipped headlight failure when the HIDs are switched on. I can only conclude that the resistance of the ballast resistor is higher than the original halogen bulb and the system reads this as a blown bulb. Has anyone else experienced this with HIDs and is there an easy fix?

Steve. :?

Posted: Sat Jan 20, 2007 6:59 pm
by ifty
welcome to the zone steve

I have the same problem to when the side lights are on the HID flicker was ment to find the low beam plug to disconnet it as its not used with the HIDs.where abouts did you find the plug?? that will sort the problem and the check control indicator its i have the same problem aswell.If i pull the light switch out quickley the its ok no check light comes on.

Hope i was of help.

Posted: Sat Jan 20, 2007 7:22 pm
by gazebo
Ifty, the Dim Dip resistors are located on the near side inner wing just under the front panel. They look like two ceramic AA batteries clamped together and screwed to the wing. If you follow the wiring loom from the resistors they lead to two plugs that you can disconnect. The plugs are quite close to the resistors on mine but the loom loops down to the chassis rail and then back up to the plugs.

I tried pulling the light switch out quickly to try and fool the check control system but that did not work in my case.

Thanks for the tip though and I hope you find the Dim dip resistor connections.

Steve.

Re:

Posted: Sat Jan 20, 2007 11:17 pm
by Brianmoooore
Pulling the two rubber connectors apart is the correct fix for the dim dip. You can remove the resistors from beside the LH headlamp as well if you like.
Plenty of E30s left the factory with these two connectors not connected to anything.
The low beam lamp failure module is tripped because the HIDs use considerably less power then the original lamps. You need to remove the lamp failure module from the fusebox, open it up, and link together pins B, K and 56 to disable it, or, if you are really enthusiastic, add extra turns to the reed relays.

Posted: Sun Jan 21, 2007 2:35 pm
by ifty
thanx for that steve will have a look and dissable it dont need the low beam.

Re:

Posted: Sun Jan 21, 2007 3:52 pm
by E30Adam
You'll run into problems though because you need low beam to pass the MOT unless you know a tester!

Re:

Posted: Sun Jan 21, 2007 4:48 pm
by gazebo
The Dim Dip function does not disable the dipped beam. If you run the car with just side lights the Dim Dip actually causes the dipped headlights to operate at a lower voltage (hence dim dipped). If you disable the Dim Dip wiring the dipped headlights will still operate normally.

Incidentally, I've just completed the HID installation and it works a dream - and for some reason the check control for the headlight fail does not operate anymore.

I'm off out now it's dark to see just how much of an improvement the HID makes.

Re:

Posted: Sun Jan 21, 2007 5:00 pm
by E30Adam
I'm not talking about the dipped beam, I'm talking about the low beam, i.e one click out on the headlight switch. If you disable the dim dip wiring, you won't have a low beam which is an MOT failure.

Re:

Posted: Sun Jan 21, 2007 5:06 pm
by stonesie
No it simply stops the Dip beam getting power when the sidelamps are on, it does not affect the power to the 5W front sidelamp bulbs, i did this mod on my 320 although i didn't fit HID's.

So it works like..
1st notch.... all sidelamps and instrument/pannel lamps (no power to dip beam)
2nd notch... As above + full 12v to dip beam

main beam opperation is unaffected :wink:

Re:

Posted: Sun Jan 21, 2007 6:08 pm
by Martinaston
This thread made it as clear as mud to me :mad:

http://www.e30zone.net/modules.php?name ... am&start=0

Re:

Posted: Sun Jan 21, 2007 7:42 pm
by E30Adam
There are 4 positions you can have the lights on an E30

1. Sidelights - Ignition key out, small 5W bulbs illuminate
2. Low Beam - Ignition on, one click on the headlight switch (main bulb, half power)
3. Dipped Beam - Ignition on, two clicks on the headlight switch, (main bulb, full power) normal driving
4. Full Beam - As with number 3 but pushing the indicator forward illuminates the inner main beam only lamps

So... when you fit HID's, as you've found out, they don't like the number 2 point mentioned above and flicker on half power. You can stop this by unplugging the dim dip resistor but you'll be without your low beam. You'll either have no lights of dipped beam. An MOT tester will check this and *should* fail you if you don't have a working low beam. If you've had a car passed with HID's and no low beam then count yourself lucky that the tester has overlooked it!

Re:

Posted: Sun Jan 21, 2007 8:42 pm
by Brianmoooore
E30Adam wrote:There are 4 positions you can have the lights on an E30

1. Sidelights - Ignition key out, small 5W bulbs illuminate
2. Low Beam - Ignition on, one click on the headlight switch (main bulb, half power)
3. Dipped Beam - Ignition on, two clicks on the headlight switch, (main bulb, full power) normal driving
4. Full Beam - As with number 3 but pushing the indicator forward illuminates the inner main beam only lamps
Lighting function number 2 was only fitted to E30s for a very short part of their production run. I don't think it existed pre facelift, and it was phased out somewhere around 1989.
The latest build date in my collection to have dim dip has a build date of 11/88.
On a lot of cars fitted with it, it has long ceased to work, as the resistors are exposed to the elements and the leads rot off.
It's not a function tested in the MOT test.

Re:

Posted: Sun Jan 21, 2007 11:02 pm
by E30Adam
That's strange, when I had my test the guy got really funny about it not working correctly and because he was a friend of my brothers said he'd let it slip the net. I'll be disconnecting that resistors then!

Re:

Posted: Sun Jan 21, 2007 11:11 pm
by buster
mine has function 2 also.When i fitted the angel headlights i had to unplug the resistor pack to stop it messing up the lit up rings.Thie does however throw up the check control panel headlight check but only when the light switch is pulled to the first click.If you pull it straight out to possition 2 then the check control doesn't pick it up.

Re:

Posted: Sun Jan 21, 2007 11:16 pm
by Brianmoooore
Brianmoooore wrote:Disconnecting the dim dip resistors shouldn't have any effect on the bulb check module.
It's the aftermarket angel eyes that are doing that.

Re:

Posted: Sun Jan 21, 2007 11:18 pm
by buster
nope because it used to do that when i had normal headlights with DIY fitted angel eyes.But with the switch in position 1 with the ignition on the dipped light came on half power.Once the resistors were unplugged it worked but threw up the check on the headlights

Re:

Posted: Sun Jan 21, 2007 11:26 pm
by Brianmoooore
Brianmoooore wrote: It's not a function tested in the MOT test.
Just had a look at the testers manual, and it DOES say that if dim dip headlamps are fitted, they must work.
If the resistors are removed, then the dim dip function is no longer fitted, (apart from the relays), so that should be OK.
Problems could arise with the new MOT system, though, where previous failures are available to the tester.