Old module does not work

[noquacks]

People,

Have a 1987 Sunbird GT,with headlight "doors" that open and close via a module controller. A similar one is here, at about 6- 1/2 minutes into the video:

The video shows the solder joints for the pin connectors may be old/bad, and he resolders it. But mine has no visible cracks/bad spots. is there a way to troubleshoot the pins via an ohmmeter/other device?

I hate to indiscriminitely start heating up joints with no clear goal. never done this before.

Thanks, people.

 

[Tha fios agaibh]

Yes. Follow the traces and check for low resistance or continuity on the pins where the harness plugs in.

It wouldn't hurt to just reflow all the joints.
Not necessary to remove the old solder, just add a little to each joint.

 

[noquacks]

Thanks, fios. I think I can do that. Regular "electrical" solder, right? First time I hear of the term reflow. Will find a youtube to study it before I try it.

 

[Externet]

I would replace the door actuator/servo with a 12V light bulb for test purposes and to rule out mechanical bindings.

 

[Tha fios agaibh]

Thanks, fios. I think I can do that. Regular "electrical" solder, right? First time I hear of the term reflow. Will find a youtube to study it before I try it.

Yes. Simply means heating it up and applying a dab of solder.

Look and see if the relay Looks black with carbon soot from pitting of the contacts. If so I'd replace it.

 

[Harald Kapp]

Yes. Simply means heating it up and applying a dab of solder.

Or use flux only, if you have. Using fresh solder is often done simply to make use of the flux core of fresh solder, not for the addition of solder.

 

[dave9]

It is usually better to *first* ask (or search for as I did to find the link below) automotive circuit questions in a forum for the respective model and generation of vehicle, where fellow owners have probably already encountered the fault once a vehicle gets older, and may have wiring diagrams to show you where to probe for loss of power (or a voltage drop across a now-resistive portion of the circuit), or if it is getting all the way to the motor and then either motor or mechanism jambed or gears stripped.

This type of headlight benefits greatly from lubrication to decrease strain, and power needed to actuate. I would do that first since it needs done anyway if you haven't already.

Here's a topic:

https://www.thirdgen.org/forums/tech-general-engine/216154-87-92-firebird-headlight.html

Yes regular solder, 63/37 would be my choice, though first I would clean the joints off with rubbing alcohol and try just reflowing what is there with some flux alone. Inspect the component soldered down, if it is not sitting against the PCB, leaving a gap, this can contribute to solder joint cracks.

If it is stressed by a connector, but the contacts look good (does not need connector replaced) you might put a bead of epoxy around the connector shell to fortify it, after cleaning both it and the PCB for good adhesion. Make sure any added epoxy does not prevent the outer casing from fully seating when reassembled.

 

[noquacks]

All good info/advice. Now I know exactly what to use, how to use it. Flux, then heat with iron tip.

But I did not mention that I do have a diagram, from the official 1987 Sunbird Shop Manual. I followed the troubleshooting steps exactly, and the manual said replace the module. Yes, I used a 12v light for that process. Easy. Now Im looking at the module. Oh- I also applied direct V to the door motors, and they did work- opened, then closed when polarity was reversed. So no problem there.

Will clean the joints with IPA (isopropyl alcohol), then do the flux/soldering iron thing. Thanks, people.

 

[noquacks]

Yes. Simply means heating it up and applying a dab of solder.

Look and see if the relay Looks black with carbon soot from pitting of the contacts. If so I'd replace it.

This relay, fios, it is that rectangular box attached to the PCB, on the OPPOSITE side of where all the soldering is? That box is clear plastic, where one can see all the "innards" thru the plastic. There are 14 solder joints underneath (on the solder joints side of the PCB). Then joints appear fine/no blackish spots........

 

[Bluejets]

Being open close device, I would tend to suspect any local limit switches used in normal operation.
These would tend to be fairly open to the elements and worth checking.

 

[Audioguru]

I bought an '89 Sunbird Turbo for my wife's first car and she loved it. Then our daughter got it.

 

[Harald Kapp]

and the manual said replace the module.

Of course it says so. They don't want you to dabble with the electronics, they want you to buy a new module.
Plus: Depending on how safety critical the module is (probably less so for the headlights) they don't want to get into trouble if something happens due to a malfunction of an electronic module that has been tampered with.

 

[Tha fios agaibh]

This area of relay (where the contacts are) may show discoloration when the contacts start to go bad.

 

[noquacks]

Of course it says so. They don't want you to dabble with the electronics, they want you to buy a new module.
Plus: Depending on how safety critical the module is (probably less so for the headlights) they don't want to get into trouble if something happens due to a malfunction of an electronic module that has been tampered with.

Right, Harald! Thats why Im trying to fix myself. With you guys's help!

 

[noquacks]

This area of relay (where the contacts are) may show discoloration View attachment 51704 when the contacts start to go bad.

Great picture, fios! Thanks! I am looking at my relay, at the contacts area, and there are (not so clearly visible in your picture) 2 contact points, which can be connected to a middle contact "joint", which can move back/forth. Kinda like a pendelum on a big clock. Right> There appears to be no blackish discoloring anywhere near there. The clear protective box is on the base with 2 retractable clips.

Any need for me to try to remove the box? Maybe to clean the contact points? Or not mess with it?

 

[Bluejets]

ny need for me to try to remove the box? Maybe to clean the contact points?

You'll likely make matters worse as the contacts usually have a coating of possibly silver which you will remove.
Best to track down the actual cause rather than poke at possibilities.

 

[dave9]

Plug the module back in, have a helper active the headlights while you measure for a voltage drop before and after the relay contacts. If the drop is insigificant, move on to the lamp assembly. If power doesn't make it that far, move backwards on the module, then the wiring diagram towards the battery.

 

[noquacks]

Finally got a nicer soldering iron, for fine tune adjustment of temperature. What temp would you say I should diel in to melt the contacts, people? 450 deg F?

 

[Bluejets]

Sounds about right for most but it depends on the job and the tip.
Finer with small tip less, bulky tracks /wiring with a large chisel tip perhaps a bit more.
Maximum heat I've ever needed to use would be up around 320C (600f) soldering tin plate fuel tanks for rc aircraft.

 

[noquacks]

Thanks, Blue. But now Im stuck. I have a Lonove 926 LED 3 iron, and the led display shows #'s going up to 480, and NO indication if these #'s are in F or C. How dumb. Tried to find it online with no luck.