QuestionQUESTION: Hi Roland..
I just noticed that the low beam does go off when the high beam is on, regardless of the headlight switch position. I will do the rest of the tests that you suggested soon, and get back with the results..
Thank you
PS. I couldn't write any more follow up questions in the other tread
ANSWER: Hi Khalid,
That is good to know, and suggests to me that either the pink wire from pin 9 of the dimmer switch to gray plug at the junction block under the dash at pin 33 is shorting to ground, or that the "high beam/low beam relay control" pin to which it is internally attached in the adjacent body computer is shorted to ground at all times. That pin in the body computer is also attached to the daylight running module pin 12 so in theory that could also be the cause of the short to ground. At least there is progress!
I don't think you need to test the relay or the relay wire itself, the problem is after the dimmer switch. Try removing the the gray plug at the junction block under the dash and measure pin 33 (pink wire) and see if it is grounded. If so that is the problem, if not, then measure to ground on the pin's socket on the junction block and see if it is grounded. It should not be unless you had the headlight low beam switch in the on position. So if it is, then that is why your low beams are on all the time. The only question then, is why the false grounding? Is it due to the DRL or to the body computer itself?
Going back to the original action by your friend. It is possible that he damaged the body contoller by putting 12v on the pin 85 of the relay because that action is not what is supposed to happen. Pin 85 does have 12v on it all the time but the relay's actuation coil is also in the circuit such that between the 12v battery source and pin 85 that actiation coil would limit the current that would be applied to the body computer 'relay control' pin (which is really also attached to the DRL, I don't know which might be damaged).
Roland
PS Many thanks for the kind nomination and remark. Feel free to nominate again as the management allows you to do so, with each new question. Many thanks
---------- FOLLOW-UP ----------
QUESTION: Hi Roland..
I have just done some testing, with battery disconnected, removing the gray plug and measuring between ground and pin 33 at junction block C3 then i get 32 ohm.
The pink wire from the switch to junction block pin 33 C3 is not shorted.
If i connect the grey plug, connect the battery and probe the pink wire, then there is no short to ground, but about 1.7 volt at all time.
Khalid
AnswerHi Khalid,
If there is always 1.7V on the pink wire when it is reassembled, even when you have the headlight switch turned off, that would mean that the voltage difference across the relay actuation coil will be 12.7 (the always present battery voltage on one end of the coil) - 1.7 = 10v so that would cause the relay to close and turn 'on' the low beams. That does indicate to me that either the 'sense' function of the body computer or of the DRL module (if there is one in the circuit which is also attached to the same pin 33) is failed. the pin has to either be at 12.7 or total disconnected and 'floating' for the relay to not close (A am not sure which way it is designed to function).
You could try disconnecting the DRL if it is still in the circuit. And if that doesn't fix it, then it appears the body computer would nead to be replaced (or repaired in the circuit related to that pin). I don't have any wiring diagrams for the internals of the body computer so it would have to be a troubleshoot by a electronics-person if you wanted to try a repair.
The alternative would apparently be to simply leave the dimmer in the high beam position when you are not driving it or not using the headlights, and then put it on low when you want low. When you put the dimmer on high with the lights on you will get both lows and highs but that may be acceptable. Just use the dimmer as a secondary headlight switch.
That is my conclusion. I hope this is helpful to you.
Roland
PS:Thanks for the nomination!
