Quick questions about the headlights.

[jetjock]

Look at the auto off schematic. It takes the retractors out of the equation and simplifies how the HL system works. Power, ground, inputs, and outputs as I said before. No can read amigo?

http://tinyurl.com/yosqqx

Pin 11 is the trigger input from the theft system. It's what puts the lights up. Iirc it's active low ie; grounds when activated. Might be what's keeping yours on.

 

[Doward]

Look at the auto off schematic. It takes the retractors out of the equation and simplifies how the HL system works. Power, ground, inputs, and outputs as I said before. No can read amigo?

http://tinyurl.com/yosqqx

Pin 11 is the trigger input from the theft system. It's what puts the lights up. Iirc it's active low ie; grounds when activated. Might be what's keeping yours on.

LOL, yep, I see it. The TDS is about the only thing I haven't looked at yet (and hence why I'm starting to now) The only correlation I can see, between the Retraction System, and the Headlight System, is that *both* are activated together, by the IC in the IR. I'm starting to think that IC is malfunctioning for some reason (that I'd really like to determine, lol)

That IC activates the stock headlight relay, and taillight relay. That IC deactivates both, as well. I have no problems with the function of any of the lights - just that they are not being told to shut off.

It's why I'm leaning so heavily at the IR right now. The IC not shutting down the base of the transistors would keep the taillight and headlight relays both energized, would it not?

Thought it'd be nice to have a complete wiring breakdown of the IR, as well

I'm getting an IR from an '89 NA, and the pigtail, tomorrow, to play with.

I have all the proper power, ground, and inputs. My outputs from the IR are what's screwed.

If I'm seeing this right, the headlights ALWAYS have ground, just switched between high and low beam. The only way to shut the headlights off in the stock system, is to de-activate the headlight relay, correct?

 

[jetjock]

The ASIC in the IR services four relay drivers: HL, TL, and both directions of the retractor motors. It uses them to handle the different functions including the theft system and auto off feature. Must be why they call it an integration relay huh?

That you can reset the thing tells me the HL relay driver (transistor) is likely ok. Can't say the same about the logic controlling it though, especially if it can be reset by removing power that is normally left on at all times ie; the IR is one of those things that's always powered. It has to be or the theft trigger couldn't operate it. Frankly I don't see where the logic gets that full time power from unless it's through pin 8 for the retraction motors. That connection must be internal to the IR as it's not depicted in the drawing. Again though, testing the relay stand alone would be a simple matter if you'd remove it.

Iirc the both low and high beam ground are switched at some point in the combo. I'd need to measure them again but the bottom line is at least one lamp ground would have to be there with the combo switch off for the lights to work upon theft triggering and I'm reasonably sure it's the dipped beam.

There's other seemingly screwy things in that drawing. For example you'd think that since pin 3 on the combo switch is connected to the high beam indicator it's also the high beam ground, yet the combo switch legend indicates it's the low beam ground and in fact it is. The high beam indicator is off when grounded on both sides. How it works when the high beams are on I'll let you try and figure out. It'll be good practice

 

[Doward]

I believe the power for the IC in the IR comes from Pin 4 - I haven't traced that wire inside the IR yet to determine for sure if it is.

As for the high beam indicator, the only thing I can figure (I just woke up, so cut me a little slack ) is that when the low beam side is grounded, you have ground on both sides, so no electrical flow.

When the high beam is grounded, the high beam filament lights, and since both low and high beam filaments use a common power point, you have a bit of power on the low beam side, to light the high beam indicator?

I suppose it'll be simple enough to check to see if I'm right, when I get back home this afternoon.

Gotta drop by radioshack, snag some LEDs to build a little test bed for the IR.

 

[jetjock]

Well, pin 4 is power but it's switched power from IG1. It won't be hot when the key is off:

http://tinyurl.com/35omco

That wouldn't do for theft operation. In fact I believe loss of power on pin 4 combined with a ground applied on pin 15 (door switch) is what puts the IR into auto-off mode. Not to mention the headlights work when the key is off so if you power 4 and nothing happens try also powering 8.

When testing you might want to load those outputs with something more than 20 ma. That said if you do decide to use leds don't forget to limit the current through them. The formula for resistance needed is R = Vc minus Led Vf divided by I in ma desired. Using 12 vdc as the supply that'd be around 420 ohms for the typical 20 ma led with a Vf of 3.6 vdc.

Yes, ground on both sides of the high beam indicator keeps it off but what are you saying, if both low beam filaments should happen to burn out the high beam indicator won't work?

I just woke up though so cut me slack if any of that is wrong

 

[Doward]

Yes, if they work the way I think they do, both low beam filaments being burned out would prevent the high beam indicator from working.

Ha, I was just looking up the LED resistance needed - thanks!

 

[3p141592654]

That is correct. It is also why installing HIDs causes your indicator light to no longer work as the low-resistance low-beam filament is gone.

I get a chuckle out of the title of this thread... I guess the questions were quick but not the answers!

 

[jetjock]

Yeah, it's turned into a monster. Ah well. The kid did good on the high beams though. I wasn't sure he'd get it. Don't get me started on the HID thing...

 

[Doward]

hehe... I'm not the electrical system SME, but I can usually figure my way out of an electrical paper sack

 

[Poodles]

jetjock: so I have an HID kit, but the high beam indicator doesn't work. Only one of the original light plugs is used to trigger the system, so could I use a resister in the other plug to make the indicator work?

I'm unsure of what resistance would be needed..

 

[3p141592654]

I looked up the wiring diagram in the 90 TSRM and it does not show pin 20 of the combo switch being grounded for headlights. I think we can chock that up to a typo in the 90 TEWD.

Poodles, if you replace the high beam indicator with an LED, then you could use a relatively small shunt resistor in one of the low-beam plugs. Otherwise, you will need to use a pretty beefy power resistor to drive the regular indicator bulb.

 

[jetjock]

Doesn't show it in the 87 EWD either. What about the current flow through that small shunt when the low beam ground is active? A resistance low enough to effectively light the led would have to be large in wattage to dissipate the power involved when the low beam ground is active and the indicator is off. Or am I missing something?

Poodles: Assuming 3p is right (imho he's one of the sharpest guys here so calling him out is risky ) I would do that. Another option would be to rewire the indicator line from connector E2 to A1, both of which are in the driver side kick panel.

It also seems a small 12 volt bulb or relay coil wired between pins 1 and 3 on the unused headlight pigtail would solve the resistor issue and would work too. It'd be on when the low beams are on and provide a path to the indicator when the low beams are off. Crude but (I haven't put much thought into any of this so maybe not) effective.

 

[3p141592654]

I would start with something like a 400ohm 1W resistor. JJ is correct, this thing is basically a heater across 12V with the low beams powered up, so need to pay attention to the power rating of the resistor. JJs bulb idea is might be preferred though, since power resistors are something of a specialty item and may not be so easy to find locally.

Rewiring the indicator does seem like a cleaner way to go.

 

[jetjock]

http://tinyurl.com/2zh79k

Poodles: Don't use that. Not that it won't work but it was meant as a little engineer humor. Very little