Dim fuel low light - instrument cluster issue

W4UWC

Original poster
Member
Nov 11, 2019
46
Nicholasville, KY
I've read a lot about "dim lights". Most of the search results were related to LED installs. I've seen ignition switches and new batteries and alternators as a possible cause. In this case it is definitely in the cluster.

The fuel light stays dim with the key off. It illuminates bright when the start sequence happens then remains dim once the vehicle is running. I haven't driven the vehicle enough to see if it comes on when the fuel is actually low. I put the cluster in another Envoy and it did the same thing so it rules out anything outside the cluster. Here is a pic of both conditions.

My question is if anyone has seen this and if so could it be repaired? I haven't split the cluster open to see if there is anything obvious.

Thanks in advance for the help!

2004 Envoy XL SLT 4.2L
 

Attachments

  • OJVI6226[1].JPEG
    OJVI6226[1].JPEG
    789.5 KB · Views: 9

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Heard of lots of dim battery lights but first I've heard of the low fuel light. Only found one thread at the OS and not much about it there:

But that light is wholly controlled by the cluster IIRC. If there are no other issues, I'd just live with it if it goes bright when low on fuel.
 

W4UWC

Original poster
Member
Nov 11, 2019
46
Nicholasville, KY
I swapped another cluster that is good but it has a lot more miles so I'd live with the dim light vs high miles I do need to verify that light which is on continuously won't drain the battery
 

budwich

Member
Jun 16, 2013
2,027
kanata
if you got the cluster out, then take a meter and do some electrical resistance measurements based on the cluster electrical schematics.... may guess at this point, is that there may be a "slight ground" or possible a faulty transistor... maybe and no I haven't pull up the schematics at this point.
 

budwich

Member
Jun 16, 2013
2,027
kanata
:-(... the bad news... based on the schematic (which isn't that good in this area), the indicators are lit as part of "serial logic" and thus "discreet test points" might be hard to come by. If you post a "good picture" of the panel and the area in question "low fuel", we might be able to provide the guidance based on "visual clues" from the board / panel. Based on the limited info in the manual, the indicator is some form of LED... the power is always provided (IGN) so what ever form of "logic" passes some form of ground (switch or otherwise)... if there are discreet elements in the area, you might be able to check those and / other connections there in. The "serial logic" suggests some form of switching transistor... that may be "leaking".
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
If draining the battery with the old cluster is worrying you, you could do a parasitic draw test.
 
  • Like
Reactions: Redbeard

W4UWC

Original poster
Member
Nov 11, 2019
46
Nicholasville, KY
Thanks so much! This truck has transmission issues and I've driven it maybe 1/4 mile so while I'm investigating that I'm also looking at other systems and learning what else needs attention. That dim fuel light was odd. I'm not concerned it will drain the battery as it's a low priority. I appreciate the replies and agree with Budwch that it needs to be opened and then visually and electrically checked. I'm betting it's a ground problem. That'll come with time. Since the fix isn't obvious then it'll be on the growing list of to-dos.

Thanks again. I'm glad I kind of stumped the experts with an unusual question!
 
  • Like
Reactions: Mooseman

Forum Statistics

Threads
23,272
Posts
637,481
Members
18,472
Latest member
MissCrutcher

Members Online