Comp-Temp Display is Very Dim

[FlyboyTR]

The following problem is on our recently acquired 2002 Yukon XL. The Comp/Temp display on the rear view mirror is very dim (lights on/off, instrument lights, up/down, day or night) and nothing changes it. At night it is easy to see, but almost impossible during the day.

I have been reading threads that discuss trouble shooting when it stops working completely, but have not been able to find anything that talks about it just being dim. It almost appears that it is stuck in night mode. Any suggestions would be appreciated.

 

[Rivieraracing]

http://www.tahoeyukonforum.com/forum/showthread.php?t=55993&highlight=compass+temp+display

 

[FlyboyTR]

http://www.tahoeyukonforum.com/forum/showthread.php?t=55993&highlight=compass+temp+display

Thanks. I had previously read that thread, plus the associated thread on the other forum. Just for confirmation...; since my display is not flickering nor going out completely after a period of time and/or temperature change; this could be caused by a cracked/cold soldier joint?

Also, I have enjoyed reading through many of your posts. You obviously have a huge knowledge base and extensive experience. Thanks again!

 

[Rivieraracing]

That's how mine started at first, it would go dim but it seems to only do that during the cold winter months. As time went on it began to do it on a more consistant basis and didn't matter if it was cold or hot out till it eventually went out completely for days on end! I found that thread on the other site, followed it to the T by reflowing ALL 6 joints and haven't had a problem since! Hit me up with questions on here if you have some, I will help as much as I can on it!

 

[FlyboyTR]

That's how mine started at first, it would go dim but it seems to only do that during the cold winter months. As time went on it began to do it on a more consistant basis and didn't matter if it was cold or hot out till it eventually went out completely for days on end! I found that thread on the other site, followed it to the T by reflowing ALL 6 joints and haven't had a problem since! Hit me up with questions on here if you have some, I will help as much as I can on it!

Thanks. Heading downstairs to pull the mirror! I'll update after it's back together.

---------- Post added at 10:36 AM ---------- Previous post was at 09:02 AM ----------

Thanks. Heading downstairs to pull the mirror! I'll update after it's back together.

OK. Removed the mirror and found the suspect parts. I resoldered all six joints. I appeared to have a small crack. Put it back together, turned on the key and NO JOY... the display is still dim and consistent (no flickering, etc). Any thoughts on what to try next?

FYI...my display is just dim (looks like it's in night mode); and is very hard to see during the daytime. Thanks.

---------- Post added at 12:26 PM ---------- Previous post was at 10:36 AM ----------

I'm not sure if this is related or not. Does the mirror auto-darken as needed or is it just on or off (based upon the switch setting)? When the darkening feature is turned on, it stays dark regardless of whether or not it is daytime, nighttime, etc. I thought it was automatic based upon the light the photo sensor was picking up (bright lights behind you, it would darken, etc).

If it is suppose to be an auto system (if turned on), and it has failed in ON mode, would that cause the Comp/Temp display to remain dark?

 

[Rivieraracing]

Thanks. Heading downstairs to pull the mirror! I'll update after it's back together.

---------- Post added at 10:36 AM ---------- Previous post was at 09:02 AM ----------



OK. Removed the mirror and found the suspect parts. I resoldered all six joints. I appeared to have a small crack. Put it back together, turned on the key and NO JOY... the display is still dim and consistent (no flickering, etc). Any thoughts on what to try next?

FYI...my display is just dim (looks like it's in night mode); and is very hard to see during the daytime. Thanks.

---------- Post added at 12:26 PM ---------- Previous post was at 10:36 AM ----------

I'm not sure if this is related or not. Does the mirror auto-darken as needed or is it just on or off (based upon the switch setting)? When the darkening feature is turned on, it stays dark regardless of whether or not it is daytime, nighttime, etc. I thought it was automatic based upon the light the photo sensor was picking up (bright lights behind you, it would darken, etc).

If it is suppose to be an auto system (if turned on), and it has failed in ON mode, would that cause the Comp/Temp display to remain dark?

So when you say you resoldered the 6 joints, did you see all 6 become liquid or did you just add solder to them? I was helping another guy on here a while back that only slightly heated them up without seeing them "puddle" up and continued to have the problem until he heated them up again to see them reflow over the joints!
Also, do you have a way to post a pic of the display so I can see how dark it is?

 

[FlyboyTR]

So when you say you resoldered the 6 joints, did you see all 6 become liquid or did you just add solder to them? I was helping another guy on here a while back that only slightly heated them up without seeing them "puddle" up and continued to have the problem until he heated them up again to see them reflow over the joints!
Also, do you have a way to post a pic of the display so I can see how dark it is?

Chris,
I really appreciate your help with this. Yes on the puddle. I can take a picture...but I'm not sure if the display will actually show up. I'll be back...

 

[FlyboyTR]

Chris,
I really appreciate your help with this. Yes on the puddle. I can take a picture...but I'm not sure if the display will actually show up. I'll be back...

OK. Here are the pictures. The readout says NW and 63 (I think!).

 

[FlyboyTR]

This is the board. The part on the left appears to have a crack between the soldier and the part. In response to your earlier question; I touched a tiny dab of solder to the tip of the gun to help with the heat transfer. Everything "appeared" to flow together. I could run it again if you think it may be of benefit. Thanks.

 

[Rivieraracing]

From the looks of your display I'd say you had the same problem that I did but reflowing the solder did the trick for mine as well as a few other guys that I've passed the info on to! And I assume that you are reflowing the solder joints on each side of the 4R3's ( 6 joints total), correct? Yes, if it was me, I would reflow all 6 of the joints yet again and when it's said and done it should be a pretty smooth transistion from the solder to the resistor if you do it right ( really no questionable line like you are seeing on the one on the left resistor like it's a crack).
Hope that make sense, keep throwing out the questions if you have anymore!