Buick Century 02 LED instrument cluster burned out AGAIN

[mhoude5]

Hey there,

I've had an ongoing issue with my instrument cluster for a couple months. I first had the LED screen shut off, did the whole googling thing and fixed it with the four resistors on the back. 3 or 4 months later the LED screen showed an orange jagged line across it and then eventually appeared to burn out. I tried more resistors, but no such luck.

I figured: OK. Somehow I burned up something in the circuit board and went to buy a different cluster at the junkyard. Got the cluster, put 4 new resistors on it to get it working, and plugged it into my car. It showed only horizontal grid-like orange lines instead of PRNDL and mileage.

My question is: Is there something in my car that is causing the LED screens to burn out or act like this? Or maybe did I just grab a bad cluster from the junkyard and should try a different one?

I think the next step is to bench test the new-used junkyard cluster to see if it behaves normally outside of my car, but I'm a little at odds on how to do that. Any ideas on how to move forward? I've been without mileage for a couple months now and every month that passes I get further from a reliable estimate of my cars total mileage.

Would greatly appreciate the help!

 

[MelsRegal]

have you tested alternator voltage output?

 

[mhoude5]

Nope, I just looked into it and will try it tonight if the rain lets up. I know what range is good, but are you expecting to see too high voltage - such that it burned out the circuit board?

 

[MelsRegal]

That is exactly what I was leaning towards, too high a voltage.

 

[mhoude5]

Voltage looked normal (~14.5). I did not see an initial drop in voltage when the car and its accessories turned on, but I have a cheap analog multimeter if that makes a difference.

 

[mhoude5]

Any other ideas on this? I'm moving cross country in a month and would like to have my mileage fixed before that (if possible).

 

[mhoude5]

https://www.justanswer.com/pharmacy/7u7pr-buick-century-need-wiring-diagram-connector.html

I found the wiring diagrams for my cluster in the link above. My question is - there are multiple grounding pins and multiple power (12V) pins. If I use an old cell phone charger (12V) wont it have a singular ground and power wire? How do I power up the multiple pins?

 

[mhoude5]

https://www.justanswer.com/buick/7u7pr-buick-century-need-wiring-diagram-connector.html

So I used this wiring diagram, and checked my connections at the source. Seemed to be good. Got power where I was supposed to, but no LED mileage light-up.

I also tested the resistor values for the junkyard replacement cluster. I am getting ~32ish for 3/4 of my resistors, which is right in line with 150/4 = 37.5 However, my 4th resistor is reading a value of 190. I have no ideas on why that is.

So now I have checked my clusters which seem to be fine (minus the weird 190 reading), and my actual car connection which seems to be reading in normal values. Checked a couple fuses for the hell of it, even though I know that the entire cluster would be burned out if that was the issue.

I am LOST!