I will start by listing my most recent mods and the condition of the locking components. I recently installed RadioFlyer Halo Taillights, and front led corners with Hyperflash harness a couple weeks ago. Shortly after I took my wife for a ride I had locked the car with the windows down and went to open the door for her, unlocked the car by hand from the inside and triggered the alarm. Felt like Rico Suave

After doing this, I blew I believe it was fuse #6 for DRLs, 10A. I just ordered a box of fuses and replaced that fuse and the DRLs are working. However I noticed that my door locks unlocking/locking on the driver side and through my key fob are no longer working. I also noticed on my passenger side that the locking does not work but the unlock works with and without a key fob. All other driver side controls work in addition to the passenger window control.

I have checked the fuses to both dcms and related fuses, all are good. I checked battery voltage and it read 12.7v while the car is off. Pulled the accordion back from both door jambs and inspected the female plugs, both sets look good. I can audibly hear noise coming from both sides when trying to lock/unlock but the mechanism doesn't turn over per the use cases I defined. It also feels like there is warmth from under the lock switch on the driver side and I believe passenger when clicking the buttons.

Seems far fetched to believe I damaged 3 relays between the two DCMs all at the same time but perhaps that is the case or damaged two actuators. Before I venture into swapping out relays, what other tests can I perform to isolate the culprit responsible for the issue? Checking voltage at the accordian plugs? At the DCM plugs? Actuators? Interior grounds? Swap DCMs?

I don't believe my lighting mods are related to this issue however, I have learned over the years when something was working well prior to a mod and perform a mod and now have an issue, revisit the mod and installation around it. Thanks guys.

 

One more piece of info to add, I pulled codes and found I have one current one, 60-IPC U1160-(Left Door Control Module). Any chance the LDCM could have anything to do with my passenger lock? If there is a loss of comm with LDCM is my best bet to start with relays on that door?

 

The only way the LDCM could affect the RDCM is through the serial bus. Something could be fubar to affect the RDCM but that is a long shot.

I think if it were me, I would disconnect the RDCM connector at A-pillar to separate the two doors. I would then focus on the driver door.

Removing the door panel may show something. If the relays seem to be working I would jumper power to the motor actuator for the locks and see if the motor is good or not.

Here is a link of panel removal:

http://www.vetteessentials.com/instr...or_handle.html

 

Thanks for the suggestions, how would I go about powering the motor actuator? Can I use my battery tender(12v) power supply and run a wire from the positive and negative to the actuator to see if the locks operate and reverse polarity to tests unlocking?

Forgive my ignorance, unfortunately electrical experience is something I'm a novice in at best. But I want to learn more about troubleshooting electrical issues through diagnosing and resolving this issue without throwing entire components at the problem without facts indicating they are responsible. Thanks again.

Ps. I just measured voltage from my passenger door harness and verified 12V of power is making it to a male pin going into the female plug that goes to the passenger DCM. Also inspected wires on the male/female side and they looked good, nothing bare exposed. I will conduct the same test on the driver side in addition to verifying the female ports all look good before taking apart the door panel.

 

Any 12v source can be used to power the motor and you are correct that reversing the leads will make the motor turn the other way.

If I remember correctly the door modules have two power inputs and there are 2 fuses involved for each door. Make sure you checked all 4 fuses. Not at home with my FSM now.

I would be glad to provide you with more info and we can discuss on the phone if you PM me with your number. Discussing an issue is much better especially if you are not that experienced on electrical issues.

Mr. Sam

 

Much appreciated for the offer and pm sent.

I will post my results in this thread so that others can learn from my mistakes or successes troubleshooting this issue.

Update: My comment earlier about the switches being warm when pressing a button was a red herring, car must have been warm from the drive is all. That is not occurring today.

I received 12v of voltage from a male pin going to the female door plug.When pressing lock or unlock I can audibly hear noise come from the DCM on the driver side but nothing from the actuator. On the passenger side the unlock works but can only hear noise from the DCM when clicking the lock button.

When testing fuses, I checked the full cluster, I believe I tested 5 fuses all using brand new fuses and received the same results. Next up will be removing the door panel, if time permits I will do so today and test the actuator using a power source.

 

Ended up pulling both door panels and swapped DCMs between the doors. After doing the swap the unlocking ability moved from the passenger side to the driver side. Indicating the relays are bad like in most reported cases I have come across. I ordered 8 of these relays from digikey...

http://www.valleyvettes.ca/door_module.html

I used this DIY to remove the relays...

JSM1-12V-5

And will use this DIY for the desoldering/soldering...


My hands/fingers are sore, took about an hour to do the first door/module, then 30minutes for the second one. I'm going to let the car sit until the relays arrive rather than put it back together only to take apart again in a few days or drive around with no door panels. Wish me luck on soldering/desoldering.

 

Looks like you are making good progress. Got your number and will call later. Don't forget the LDCM and the RDCM are not the same but they can be used for the test you did. The LDCM has the Memory interface. You would think GM would have made them the same but I guess this saved them a few pennies.

PS: As I said in my PM to you my info says the lock and window relays are different. I see you ordered 8 of the lock kind. Maybe we can see if the circuit board footprint is different or not before you wrap up your project.

Here is the P/N I have for the window relay:

Mouser Stock number is 551-EP2-3N1S.

The same Forum source for this number also provided the same # for the locks as you ordered.

 

Thanks a lot Sam for taking the time to talk to me on the phone this morning.

You pointed something interesting out in that one of the two relays for the power windows, that runs vertically has a different part number between the passenger and driver side.

The P/N on the driver side is: 09389689
The P/N on the passenger side is:09389699

The 3 relays running in parallel on both door modules have the same part number on both modules. I ordered 8 just in case I booger up one or a couple and/or ever needed to replace again in lieu of a different root cause that fried the relays.

My power windows are having no issues just the locks, however if they had, had issues I am not sure the swap test would work because the part number differs for the relays.

Below are pictures of the driver and passenger circuit board for reference...

Driver:










Passenger:







I have a cheap 8$ soldering iron and figured this would be a good time to invest in some soldering supplies as I have had the need to solder several times over the last year. I have ordered the following...

Soldering Iron -
Solder -
Solder Sucker -
Desoldering Wick -
Fine Soldering Pencil Tip -

I purchased both the solder sucker and desoldering wick to try both and see what works better for me on the solder removal. Probably will be attempting this on Wednesday or Thursday.

If anyone would like me to take more pics of the circuit board or door while its disassembled I would be more than happy to.

 

Those pictures were VERY helpful. Based on those, I went back to the FSM and here is my conclusion.

The 2 relays at the bottom of the stack of three are for the door locks.

The relay above that is for the heated mirror element.

The NEC "vertical" relay is for the windows. It is the only one with 2 coils and sets of contacts for UP and DOWN window motion. I verified this with the manufacturer relay Specfication Data from both relay models.

The mirror motor relays are much smaller and separate from these 4 since they have a very small current draw. I don't see them in these pictures since these pictures don't show the entire board.

We know the LDCM and the RDCM are different because the LDCM has a Memory function in it on the circuit board.

If you notice the white sticker on each relay IS the SAME as the GM part number for each door module. Apparently that was done to identify the difference between the two circuit boards until they were put into the plastic boxes (which are identical) and then that same P/N was placed on the outside also.

If you notice the relays have some additional numbers that are different while each model of relay all carry the same basic model number. These have no affect on the model or design. They are lot/batch numbers that are typically put on products in case of issues later to help identify suspect products. Also, Quality Control testing will normally test a certain percentage of a lot/batch to a higher standard than normal production line inspection/testing.

The door relays normally get the most use so they seem to fail more often.

Thanks for the pictures Nick.

 

That makes sense, when looking at the two boards front and back, visually I can not tell a difference between them other than the identifying sticker.

Here are a few more pics i took of the entire boards for reference.

Driver:





Passenger:

 

Thanks a lot for the help sam, got the new relays installed today and the locks are back in business. Between the two doors needing the fix I probably saved myself 3-400$ had I bought some used DCMs. The most complicated part for me was separating the relays from the circuit board after pulling the solder because I didn't have the right tool. Picked up the puddy knife pictured below from home depot for 5$ and it worked like charm.

If I can do this job anyone can.

 

I actually used both. I used the wick first and would bend it in the shape of an O and set it on the solder joint. Let it absorb the bulk of the solder while not having it touch anywhere else on the board. Then bring in the solder sucker to clean up, typically with 3 pumps on each solder joint.

When soldering new relays in, make sure to thoroughly clean the doughnut holes so no solder remains and clean with alcohol wipes. I also wiped each prong on the new relays with alcohol wipes. On resoldering, I had one stubborn dunut/prong that wouldn't absorb the new solder and I think I may not have prepped enough on that doughnut/prong, had to redo it. Flux paste may have helped as well on that stubborn prong.

 

I have a 2004 C5 and all of a sudden the power door lock on the passengers side would not lock and unlock. By pressing the switch on either door only the drivers side would work. By using the key fob only the drivers side would work. Do you guys think it is the relays or the actuator? Great write up here.

 

Huh??????????????? Did you read what you wrote?

 

Thanks for pointing that out i corrected it already

 

Make sure I/P fuses 30 and 31 are good.

If they are then I would jumper 12 volts to the lock actuator motor and see if it works.

If it does then it is most likely the 2 relays in the door module.


Here is how to access the door.


http://www.vetteessentials.com/instr...or_handle.html


I just want to make sure that you can make sure the passenger window will go up and down so I don't need to look at other things.


Mr. Sam

 

Thank you Mr. Sam, I will try to find the fuses my car did not come with a manual.

 

You need a manual. You have no idea how many questions get asked here because they didn't bother to read the OM. Download one for free here.

http://justgivemethedamnmanual.com/p...rolet+corvette

You should also find the fuse and relay numbering on the backside of the fuse box covr.


Mr. Sam

 

C5 Drivers Door Locks Inoperative
GM module pn 09389689

OEM installed relays Aromat JSM1E-12v-5-H15

Digi-Key replacement pn. 255-1240-ND.

MFG. pn Panasonic JSM1-12v-5.

Replaced all relays since with Digi-Key whereas they had the Panasonic pn on the relay.

Total cost delivered. $9.41

Used small screwdriver to apply pressure to release relay when applying heat to the opposite side joint for release.

Used small pin vise drill to clear solder restricted holes.
















New Relays Panasonic from Digikey<br/>





Partial pic showing clean 5 pin holes ready for new relay.





Drill held by pin vice