I know you're tried of this

[Ronnie]

Don I will try to help you with the light (I'm assuming it is the LH Door Courtesy light). Please answer the following questions:

1. Does the RH Courtesy light work?
    
   
2. Do you have power on the orange wire (12 volts - measure between the orange wire and a known good ground) where it connects to the light fixture?
    
   
3. Do you have a ground on the ppl/yel wire?
   

All this assumes the door is open and the light should be burning.

[Don Hudd]

Ronnie, yes rh works, I even changed fixtures and jamb switches to make sure that was not the problem.

No power at the orange wire if curtesy lights are on, if door closed, jamb plunger pushed in out light go out by being timed out then power at the orange wire and lock witch works, no power ever to the door light fixture, most likely because not suppose to be there if door closed.

I am guessing bad ground to the purple wire, but rechecked connection under pass. seat, that is good, don't know how to check otherwise.

A question I have is, on the door jamb switch the FSM shows a white wire, black/white wire, but on mine there is a 3rd blue wire. Can not find it at all in the manual.

Passenger side works as it should.

Thanks Ronnie,

Don

[Guest Mc_Reatta]

Third wire on the door jamb switch is for the theft deterent. Not a player here.

Need to check for 12v at the splice under the driver's seat that is where the door lamps and door lock switches get their 12v. Careful, hot all the time. If you ground it by mistake you will blow a fuse.

Need to check that this splice is good, and then why 12 v isn't making its way up the orange wire to the splice in the driver's door. Should always be 12 v at the door light socket and at the door lock switch.

The light turns on when the purple wire is grounded by the courtesy light relay by the BCM.

[Ronnie]

no power ever to the door light fixture, most likely because not suppose to be there if door closed.

You are thinking about it wrong. You should have 12 volts on the orange wire at ALL times. The light is controlled from the ground side of the light circuit (ppl/yel wire) by the courtesy light relay.

You have a bad connection somewhere in the orange wire. Until you get power at all times on the orange wire at the light, there is no use in checking anything else. The power should come directly from fuse #2, through the splices, under the drivers seat and in the door, to the light via the orange wire. There are no switches in that circuit that break the circuit to control the light. You need to trace the orange wire all the way from the light down to where it connects to the splice under the seat for continuity.

[Don Hudd]

Then why is there power to the orange wire when curtesy lights not on, this tells me splice(which has been checked 2 times) under drivers seat is connected, do not have power to the orange wire in the drivers door when curtesy lights on only when off then have 12v at the splice in the door.

If my thinking is right, there would be no power to the door light when door is closed(plunger pushed in) or when timed out. Again, power to the orange wire in the door when curtesy lights not on.

[Guest Mc_Reatta]

Negative. We are trying to figure out why there isn't 12v at all times in the orange wire in the door.

Don't confuse the splice in the orange wire with another one in the same area which has orange wires with black stripes. They go to the door lock relays and the trunk release relay.

[Ronnie]

Then why is there power to the orange wire when curtesy lights not on, this tells me splice(which has been checked 2 times) under drivers seat is connected, do not have power to the orange wire in the drivers door when curtesy lights on only when off then have 12v at the splice in the door.

If my thinking is right, there would be no power to the door light when door is closed(plunger pushed in) or when timed out. Again, power to the orange wire in the door when curtesy lights not on.

Don, In this case your way of thinking is wrong. I know it is confusing that there should be power going to the light at all times. But the way the BCM, controls many electrical devices, including the interior lights and associated relays, is by completing or breaking the GROUND side of the circuit. You must accept that as "normal" in order to successfully troubleshoot many of the electrical circuits on your Reatta.

The splice under the seat may indeed be good but for whatever reason, be it a broken orange wire or a loose connection, you have a problem of some sort that is keeping power from getting to the light at all times. Please read my last post again. I believe it accurately explains the reason your light is not working.

Edited September 16, 2010 by Ronnie (see edit history)

[Guest mongeonman]

Try grounding the light,you will see.

[Don Hudd]

Ok, what am I not getting? Should there be power to the orange wire at the split in the door that feeds the power lock and then to the light? I think there should be so the power lock would work with the door opne or closed. Is this correct? If so, I only have power there when door is closed(or curtesy lights timed out or when jamb plunger closed) when door is closed power lock works, when door is open power lock does not work.

I now understand about the bcm controling the light, so I can see why no power at the light with door closed(no curtesy lights on) but should have power when door is opened, but again with door open no power at splice in door, power lock does not work.

Door open no power, door closed power.

[Ronnie]

Please see comments below.

Ok, what am I not getting? Should there be power to the orange wire at the split in the door that feeds the power lock and then to the light? I think there should be so the power lock would work with the door open or closed. Is this correct? Yes, that is correct. There should be power on the orange wire all the time.

If so, I only have power there when door is closed(or courtesy lights timed out or when jamb plunger closed) when door is closed power lock works, when door is open power lock does not work. You will have to trace out all the orange wires and find out where power is being lost when the door is open.

I now understand about the bcm controlling the light, so I can see why no power at the light with door closed(no courtesy lights on) but should have power when door is opened, but again with door open no power at splice in door, power lock does not work.

Door open no power, door closed power. I would suspect the wire moving inside the bellows between the door and the door jam could possibly be broken. Again tracing the wire and testing for power along it's path to see where you are losing it is the proper course of action.

[Don Hudd]

Thanks ronnie, I will try and do that, but seems strange that the door can be opened, no power, I don't move a thing, curtesy lights time off, have power to the lock, hard to believe broken wire when not working, nothing is touch, lights go out...power to the lock

[Don Hudd]

also as stated earier when MC asked yesterday, when door light fixture is disconneted, no power to lock whatsever, curtesy lights off, door closed etc.

[Guest Mc_Reatta]

Don,

I quit thinking this was a standard problem a few days ago when you reported the 12v at the lock switch went away when you disconnected the connector from the light, and you said there was a screw under the outside door handle.

I can't think of any standard failure mode of that circuit that would cause that, so Im' guessing that there has been some customization along the way.

I recommend going after the 12 v issue first since that is the obvious departure from standard, and once that is resolved and the light still doesn't work, to go after the ground side. The purple/yellow ground wire is supposed to go directly from the light connector to the splice in the floor under the passenger's seat without any other connections or splices, so there isn't much to see or test other than continuity from the connector to the splice.

Even if that purple wire was broken, it could not account for the 12 v not being on the orange wire in the door.

Need to start under the driver's seat at the orange wire splice (not the orange with black stripe) and verify that there is 12 v there all the time with the door light connector disconnected, and when wiggling the wires and splice.

Then repeat the test at the splice in the driver's door again with the light connector disconnected and wiggling the wires and splice, and opening and closing the door to see if there is a break in the wire as it passes from the car into the door.

If you do not get 12v at the splice in the door at that point, need to disconnect the power lock switch wires from the switch to eliminate any possibility of something inside that switch being wrong of modified somehow and affecting that orange wire.

If there is still not 12 v at the splice, the orange wire to the lock switch and to the light connector, then there is a break some where in that wire betweeen the splice in the door and the splice under the seat.

Report back when you get that far and we can then determine the next steps to take, either to find where the break in the wire is or if you find another cause.

As you do all these steps be vigilant for something that doesn't look right. A wire tapping in to that orange wire between splices, a connector that looks damaged or broken. Anything that doesn't look like stock to your eye.

[Don Hudd]

MC, today I only had time to check the lock switch, again what is strange is that there is 12v to the splice only when curtesy lights are off. Today I waited with lock switch pulled, meter to ground and to the orange wire in switch, no voltage ubtil curtesy lights timed out, still with meter connected as stated, immediately 12+volts, disconnect door light fixture, immedately no volts, hooked fixture back up...12volts at switch. I did not move the door what so ever, so seems that would elimiate loose or broken wire.

Oh, also with meter still hooked up to the lock switch, having voltage as to lights were off(timed off) pushed jamb plunger , let go as if opening door, lights came on(not door light though, immeiately no power.

I switched fixtures again today also just to elimiate that, no difference.

This has now become more of a chalenge than really need this fixed. The lock itself still works all the time with the remote.

The screw is just holding the latch switch on so I don't think that is the problem. Looking at the FSM skimatic(Sorry bout the spelling) everything looks as it should(purple/yell under rh seat, orange under lh seat, orange wire splice in driver door.

I know I'm rambling, but again, power to the lock switch,meaning power to the splice when curtesy lights off, witch would make sense that now power then to door light because it is not suppose to be on when curtsy lights are off only when they are on, which is when no power to door splice.

Sorry so long winded, just trying to give best info I can.

Tahnks Mc and all

Don

[Guest Mc_Reatta]

When the 12v is present, (courtesy lights off) on orange wire, disconnect the light connector and read the voltages present compared to ground of the wires in that connector.

Orange wire 0, purple wire ?

Is there any voltage present on the other wires to the door lock switch when either there is 12v on the orange wire or when there isn't? Believe there are 2 black wires

along with the orange wire connected there.

[Don Hudd]

MC, when I disconnect the light connector the voltage immed. drops to 0, puple wire was something like .15, don't know why I checked but I did. Don't know what it means though

[Ronnie]

Don, where are you connecting your meter ground lead? It should be connected to a bolt or something metal on the body of the car. Not on the door or one of the ground wires going to the lights.

To get the voltage readings you are getting it seems like you would have to be reading voltage between the orange wire and the purple/yellow wire (that goes to the courtesy light relay). Although the ppl/yel wire grounds the lights to turn them on, it should not be considered a chassis ground for testing purposes. IF you are testing that way, the ground is what you are losing when the courtesy lights time out. Not the power (12 volts). That would explain why pushing the door jamb switch changes power readings on your meter. The BCM senses the change from LO to HI when you push the door jamb plunger and resets the courtesy light timer, and also closes the contacts in the Courtesy Light Relay making the ppl/yel wire a ground wire.

A note about the switches on the doors:

They do not make or break or make the circuit (orange & purple/yellow wires) to control the lights. They only supply an input to the BCM telling it if the doors are open, closed, or the door handle has been lifted. When the BCM gets that input signal it picks up the Courtesy Light Relay to complete the ground side of the light circuit (purple/yellow wire) to turn the lights on.

I hope this helps. I know it is frustrating to chase down electrical problems. The better you understand how the system works the easier it will be.

[Guest Mc_Reatta]

Don, I've been looking over the power distribution diagrams and the wiring diagrams, and using the information your providing, and have determined that the orange wire has a complete break somewhere along its run from the splice under the drivers seat to the splice in the door.

You can either replace the whole wire or track down where the break is and repair the break or if it is in a spot that can't be gotten too, replace a short section of the wire to jumper around the break.

The obvious place to start looking for the break is where it passes through the door.

The reason that the door lock switch works when the courtesy lights are off is that there are enough resistive loads connected to the master purple/yellow "floating ground"wire that it is a power source compared to chassis ground. There is enough current in it for the lock switch to activate the locking relay.

If you want to prove this to yourself, with the courtesy lights off, ground the purple wire in your disconnected door light connector to a good chassis ground and see what happens.

[Don Hudd]

Ronnie,, test was to ground not orange to purple, orange to chassis ground, then tryed purple to chassis ground

[padgett]

Just use these.

[Don Hudd]

MC I will try that. as you can see, i am not an expert on elec. never thought of that because the purple wire does not hook to the lock button, but I now see how what you say could be whats up.

Thanks guys, will report

Don

[DAVES89]

Dave all 3 switches in the door need to be working in order to get the show.

To find out which switch or switches aren't working properly you can either check the BCM data values for B 103, 105 and 106 off the CRT, or you can just see if the mileage displays on the dash and the courtesy lights come on when you raise the door handle from the outside, when you open the door from the inside do the courtesy lights come on? and lastly, if you are inside and have the ignition on in the run position and put the car in gear, do you get the door ajar on the crt?

The specific steps to perform the BCM test were posted in the new old guy on the block thread a little while ago.

Once you know what switch your trying to fix, then you can use the color code chart info to find the splice under the carpet to go after.

OK I did the test as you said. I do NOT get the mileage display or the courtesy lights coming on when I lift the latch.

I DO get the courtesy lights when I open the door.

I DO get the "Door Ajar" warning on the CRT.

I donloaded the info [Door Switch Troubleshooting Guide & Circuit Color Codes for Floor Splices] from Ronnies site and will try fixing it when I get back.

We need to get up at 3AM so I need to quit.

BTW McReatta your parts are going out Monday The rest of you guys when I get back.

Edited September 19, 2010 by DAVES89 (see edit history)

[Guest Mc_Reatta]

Dave, It looks like the door handle switch is the culprit. I'll have you run the BCM test to verify when you get back and then you can figure out whether you want to start in the door or under the carpet.

If you're like me which ever you pick to start will be the wrong place :confused:

Don, I should have figured it out a day or 2 earlier. Buick hung at least 5 light bulbs off that purple wire. These days that's considered poor design practice due to how treacherous it can be to prevent cross talk and reverse currents with multiple floating grounds. Saved them some money in running more copper wire though. Need to remember resistive loads like light bulbs are not switches or diodes, current can run through them in both directions. Since there was no 12v in the orange wire in the door, the sum of voltage and currant from the other courtesy lights could run up through the purple wire through the door lamp into the orange wire and over to the door lock switch. Since there were so many resistive lamps in the path, it wasn't full strength, but still enough to allow the door lock relay to operate when you pushed the switch and it went to ground through the lock relay but not enough to light any of the lamps. As soon as the courtesy lights were commanded on, it took the path of least resistance and went through the energized courtesy light relay to ground. Also, if you unplugged the door light connector, it could not run from the purple wire through the light bulb and back out on the orange wire.

Knowing that, it still doesn't tell you where the break in the orange wire is. It will take you to figure that out and fix it.

Edited September 19, 2010 by Mc_Reatta (see edit history)

[Don Hudd]

SUCCESS!! Mc and Ronnie, you guys rock, yes it was a broken orange wire, it was under drivers seat. I know I said I checked it twice, whbich I did, but while looking for a break and following it back, I found it laying in the channel on the other side from the connection. I missed this because while looking at the FSM page A8-114-2 splice s311 looks to me like 1 wire going into 3, which I had, but it appears that it is 2 wires into 3. The other orange wire that I did have connected is going towards the rear of the car.

Anyways a huge THANK YOU!! and thanks for staying with me on this and being so kind.

Don

[Ronnie]

I'm glad you were able to trace down the problem.

[Guest Mc_Reatta]

Stick a fork in 'er she's done!

Great news!

Yeah, you needed to look at the fuse block details on page 8A-11-3, and you would have seen the 5 wires at S311. Besides all the courtesy lights and door lock switches, they also power the keyless entry module and power mirrors.

Congrats on a job well done. Now you just have to put it all back together.

[Guest 88atta]

Don Hudd,

Great news..maybe I lead you astray more than once with my plain orange wire postings of 3 to 1; it worked for me then but now after reading Daves89 posting about "Door Ajar" warning on the CRT I wonder if I may have missed an orange wire as well. I do not get a warning if my door is ajar on the CRT. It may make a difference because the 88 didn't have the keyless entry option; I don't know. What do you think Mc_Reatta if you are reading this? Unfortunately I have re-assembled the Stealth as of yesterday, carpet, seats, etc. and everything seems to be functioning super until I read the Door ajar posting. I would think that the door ajar etc, would reflect on the IPC and not on the CRT. Comments please.

Edited September 21, 2010 by 88atta (see edit history)

[Don Hudd]

RD, on my 89 under drivers seat there is 2 orange going into 3. 1 goes to the drivers door for the light and lock switch, the other going towards rear of car. most likely for the keyless entry which always worked because this wire was the 1 that was always hooked up. My show came on after hooking up the grey wires under pass. seat, which I know you have been though thoroughly,

I am sure MC_Reatta will shed some light on this(pun intented) he was and is a big help as were you on your post which got me startwd further down this path, glad I took the trip!

Don

[Guest 88atta]

Thanks Dono for the clarification.

Ron

[Guest Mc_Reatta]

RD,

Let's start fresh. Too hard to go back thru all the posts.

What were your results when you did tests B103 and 104 in diagnostic mode under BCM data?

When door is closed it should read HI, when door is open is should read LO and go back to HI when door closed all the way. 103 is for driver's door, 104 for passenger"s.

The ground for these switches are black wires with white stripes if 88s used some colors as 89s. Splice is located under the passenger's seat. Lots of wires here, 5 at least.

The power for the drivers side switch comes from the BCM on a Gray wire with a black stripe. Doesn't go thru a splice.

[Guest 88atta]

Mc_Reatta,

After following your instructions in "New old guy" link I thought had resolved all my electrical issues and I still think I have. I have all the courtesy lights, dome, the Show (WOW), door handle lights etc.. The only thing that threw me was Don's above posting on a fifth wire on the orange splice and Daves89 "Door ajar" posting on the CRT. I thought that possibly that if I had missed a 5th orange wire on my repair and it could partially explain why I don't seem to have the door ajar posting with the door open on my CRT or IPC. I'll go back and check the 103 and 104 postings again but they were fine when I first tested them..105 &106 were originially bad then but since been corrected. Since I don't remember ever having a door ajar dash posting, I really do not know where to look for it; I wouldn't expect it to be on the CRT but on the IPC. Can you clarify where that alert would be found? To prevent this link to be an on-going thing and Don's problem has been resolved, after I test the 103 and 104 codes and should I have a problem in that area, I'll open a new electrical subject link but prior to that I'll report back on progress either way I go; thanks.

Ron

Edited September 21, 2010 by 88atta (see edit history)

[Guest 88atta]

Mc_Reatta,

After re-reading your instructions on "New old guy" I think I'll definitely start from scratch on 103, 104.105.106 etc. to include pulling switches again and using that DVM. Probably won't get back for a day or two..have a few things on my "Honey do list " that have to get done first.

Edited September 21, 2010 by 88atta (see edit history)

[Guest Mc_Reatta]

I don't think you have a problem unless it would be on the passenger's side. B 103 and 104 will tell you if the BCM is getting the proper signal from the door ajar switches. I believe you have confirmed that before, but won't hurt to recheck.

The warning message does appear on the CRT. It will state which door is ajar.

Believe for the warning to appear, that the car has to be in run with the car in gear. Don't think it will come up just with ignition in run so you don't get a message when you are stopped and pop a door open to let someone in or out with the engine running.

The orange wires don't have anything to do with this one. The fact that you have the show indicates that the driver's side is working properly. The onlly use for the one on the passenger's side is to post the warning on the CRT.

[Guest 88atta]

Great,

Based on the above, I'll check the door opening with the car in gear hopefully later today. If it doesn't pan out I'll start fresh but concentrate on the passenger's side. Thank you for all your patience, assistance and quick reply.

Ron

[Guest 88atta]

Mc_Reatta,

Dang..you were right again...car in gear reflects door ajar on CRT. Do you sleep with that service manual or did you possibly help write it? Thank you oh great one. Maybe I should move down to Tennessee to become enlightend. I going to take Stealth out in the next couple days to blow out some carbon..maybe I'll run into one of those SR71 Blackbirds (NASA & USAF) on one of my runs...hope not, because I may embarress it and it's driver (pilot); thanks.

Cheers

Ron

Edited September 23, 2010 by 88atta (see edit history)