There are several ways to make this work, but I'm not aware of anyone simply trying it. Maybe I should buy a set this weekend?

If it tripped the lamp monitor, I'd just put a high wattage resistor on each light circuit. In parallel with the lamp, so it wouldn't affect the current drawn by the LED'*, but would consume enough to satisfay the lamp monitor. If you set it up with the right threshold, you could still maintain the ability of the lamp monitor to detect an LED failure, regardless of the condition of the resistor.

the resistor that is to be put into parralel with the LED will have to be calculated so that result is facorty bulb resistance.........for instance the factory bulb is 10 ohms, the new LED you buy is 20 ohms (not drwing enough current) so in parrelel with the LED another 20 ohm resistor is introduced to the circiut, whalla 10 ohms.........if the led would fail which i belive fail slightly diffrently than filliments but in this case lets say it would burn up or get hit by a rock or you hit a damn deer who was caught in your insanly bright HIDs it would become open going to infinate resistance, the circut become a 20 circuit due to the resistor, and the ALM annunciates.

nicky

But how about the HID problem? The monitor detects the change in current draw, as it tapers off. I would still think you have the same change in current draw, with or without a resistor?

two more questions does the ALM measure rate in change of current or a current value against a preset standard with a tolorance, question 2.....i am unclear how the light from HID head lights are produced is it a large light emmiting diode or is it a filiment based sytstem useing a special filimant projector and under pressure gas?

nickyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

Lest we forget, the first word in the ALM unit is "Adaptive." That is, it learns the current flow of each circuit over time (or more accurately, over a certain number of driving sessions that I have forgotten, maybe 20 or so), and then flags an error if the current flow on any given circuit falls below the expected amount. So in theory, if you swapped in LEDs for taillights (a horrible idea for reasons which I'll get into shortly), the ALM would probably complain at you for 20-50 driving sessions, then give up the warning as it "learns" the new expected current flow. After that, if you were then to unplug the LEDs, let'* say, the current flow would now decrease again and the warning would come on again.

But as far as sticking LEDs into the taillights in place of the incandescent bulbs, we've been all down the garden path on this one, and the bottom line is that taillights will barely light up as a result, unless you swap in an LED unit that actually sends light out sideways as well as directly.

The incandescent bulbs send light out in all directions, obviously, and the purpose of the big reflectors behind those lenses is to gather the radiated light and bounce it rearwards, through a portion of the taillight lens. The reflector is very carefully designed to fill the entire taillamp (or marker lamp, or whatever) lens with light, even though that light is really only emanating from a single point source in the middle: the bulb.

Compare that with aftermarket LED bulbs. These use one or more LEDs to emit light, but I have to see any that try to dissipate light to the sides as effectively as end-on. Their radiated light distribution is just lousy compared to incandescent bulbs, leaving the reflector with very little light to actually gather and redirect through the lens. Consequently what used to be bright, blazing, ruby-red taillights with incandescent bulbs turn into dark lenses with little LED blobs in the middle afterwards.

I believe someone once posted an image showing a taillight comparison on a Bonne with incandescent bulbs on one side and LEDs on the other, and the difference was dramatic.

One other note, which may be getting a little off-topic now, but you'll also have problems swapping an LED wedge-base side marker bulb into the front side markers unless that LED bulb will accommodate current flow in both directions, not just one. This is because current flow for lighting the side marker with the running lights flows in one direction through the bulb; current flow for lighting the side marker with the turn signals flows in the opposite direction. An LED by definition allows current flow in one direction only; an LED version of the #194 wedge-base bulb will need some creative internal circuitry to enable illumination in either direction in order to function properly with the blinking front side marker design that the Bonneville has.

I believe it'* the latter. Dad'* 2000 BMW has HID headlamps, with some rather scary underhood warning labels about 25,000-volt operating levels and such...

So the ALM uses similar technology as smart transmisions which learn the driving style of a particular driver and adjust shift points and other aspects of the drivetrain. I wonder why pontiac used this technology, why not use a standard current with a tolorance, i cant belive pontiac had this type of technology all the way back in 92,


nickyyyyyyyyyyyyyyyyyyyyyy

The ALM detects a relative change in current. The baseline is reset when you turn just the parking lamps on. That is how it becomes adaptive.

The HIDs have no filament. That'* why they call them "capsules." The electrical current is forced to jump a gap between two electrodes.

I don't think it'* really all that advanced: you have a chip that monitors current flow, compares it to what it saw last time, or to a calculated average of the past "n" driving sessions, etc. The learning angle probably helps it accomodate fluctuations over time, like increasing resistance in the wiring as it ages, clueless drivers swapping in the wrong replacement bulbs, etc.

The learning concept in general has been around for quite some time. For example, back when I was doing service manuals for Ford in the mid-1980s, we had warnings in the manual for the EEC-IV processor (and earlier versions, too, I think) about how the Keep Alive Memory (KAM) affected the car'* performance and the driver'* perception of it, and if the KAM was lost due to power failure (e.g. changing batteries), the car would operate roughly for a while until the KAM re-learned the best operating parameters.

Sometimes this was a benefit; e.g. if the engine had an extensive cleanup or replacement of emissions or control parts, disconnecting the battery to _force_ a re-learn was sometimes recommended.

Anyhow, getting back on-topic here, if you haven't yet got the factory manuals for your '92, by all means do so, because there'* a lot of useful info in there that third-party manuals don't always have, and of course every page is devoted is devoted to your specific car, not an attempt to cover multiple models or multiple years.

thank you for all that in depth info andy, so the HID headlight is projecting an arc of electricity, wow that would explain all the high voltage warnings,
thanks again,
nickyyyyy