LexLS

Over the last few days I have been attemping to fix a broken 91 instrument cluster I bought on ebay. What I have done is recap all the boards. Reading the sticky thread I thought this would fix 90-92 gauges but no. 90-92 clusters have totally different circuit boards with different capacitors. I will list some problems I know of and if they have been fixed or not by recapping. I would like to get some feedback from 90-92 LS owners to see if they have these problems or not. I would also like to hear if anyone has further ideas on fixing the half lit speedometer needle.

Problems:
-Backlighting does not light up or takes a while to fully light up..........not sure, my used cluster lit up fine on the bench
-Slow reacting or non-functioning fuel and temp gauge needles......fixed
-Speedometer needle that only lights up halfway......not fixed
-Flickering tach or speedo needles........not fixed

If you know how to fix this let me know! I have read through the entire sticky but it only relates to 93-94 LS clusters. Even if your cluster works I want to know .

Here's what my project cluster looked like after recapping:

Shaffer

I think there is a fixed thread here that explains about the needles. Here are a couple of photos of the still original cluster in my 90 LS400. Luckily- still in perfect working condition, as are the guages.

(knock on wood)

Shaffer

Another view:

(Yes, this is the lowest I had let my gasoline get, but only because I was in a hurry to get home and did not stop and get gas). Also- that odometer was reset when the car had 1/2 tank of gas, because I had a trip I had to check the mileage on.

LexLS

Glad your lights are working fine, thanks for posting

The lights in my cluster light up fine and I have no needle problems. I do have a slow fuel gauge needle and I think the temp needle is not working properly either. The picture I posted above is from the cluster I bought on ebay.

I'm going to search for some old threads on this, maybe I'll find something. Again, I have read the entire sticky thread on this and it does not help 90-92 owners at all.

Where are all the other 90-92 owners? Do your lights work? Fuel and temp gauges working properly?

nk1983

my fuel gauge lights up halfway..speed gauge is out completely.. everything else is fine.. let me know if you find a solution..im desperate and i dont want to replace my whole cluster! btw your site is great!

EDIT: btw when i say my speed gauge is out completely that sounds mis-leading.. i mean the lighting of the actual speed needle. ..it still moves fine etc.

dj.ctwatt

on my 90, when my speedo gauge went out, it was from a faulty speed sensor. . . #2 if I remember correctly. It would stay at zero, and every long long once in awhile it would bounce around erradicly from 0 to 160 and then to 0 for a few seconds, then go back to 0 and stay there. It was replaced and the problem went away.

CUMan

My 93 LS 400 had this problem with both its speedometer needle and tachometer needle. It also had the problem of the dash display not being illuminated when the car was started in cold weather.

I sent my display to Jim Walker in Fresno, Ca., and he fixed both the needle problem and the non-illuminating display problem.

As I understand what Jim told me, the needles have a coating on the back of them that creates a circuit from the pivot point of the needle to the other end. This coating material apparently deteriorates and cracks over time, and the circuit is shorted out. I believe that he removed the needles, cleaned off the old material, and reapplied new conducting material. Both needles work fine now.

Note that my car is a 93; however, I would bet that the needles are the same type.

LexLS

Very helpful information CUMan . This makes perfect sense. I thought about why the black material on the speedo needle was there and why it was cracked. The needle actually illuminates to the point where the conductive material broke. The question now is what is this conductive material that's on the needle?

And yes, the needles are the same for 90-94 models, it's the circuit boards that are different

CUMan

I would suggest that you contact Jim Walker at jimlwalker@sbcglobal.net.

I am sure that he could fix the needle if you want to remove it and send it to him. He charged me a very small amount to fix mine since he already had the dash display disassembled. If you want to work on it yourself, perhaps he could give you some guidance.

Also, I would suggest that you do the same repair to the tachometer needle even if it appears to be okay. My tachometer needle appeared to be working okay when I sent the dash unit to Jim. When he returned my unit, he said the tachometer needle backing was also cracked and would have started to go out soon.
He did his "treatment" to both the speedometer and tachometer needles.

LexLS

Well I emailed Jim and he is probably not going to tell me how he fixes them .

CUMan do your repaired needles look exactly the same as they did before? In other words, is there a black backing around the back of the needles? Can you take a closeup of the repaired needles so I can see them? That would be the best....

I looked at the needles closely and the black backing looks more like a 3/4 tube. It seems like it doesn't even touch the needle other than at the ends...hmmm.

CUMan

Yes, the needles look exactly the same as they did before, i.e., before the speedometer needle starting darkening.

I cannot really see the back of the needles looking at them through the plastic face plate of the dash display. With the display being inset into the dash, you can't get a good viewing angle to look at the back of the needles. All the needles (temp, fuel, speedometer, and tachometer) have a black tip on their outer end. This tip is not noticeable when the display is lighted because it blends into the background.

Sorry I could not be more helpful.

retrodrive

Ask OLT if he can fix needles. I am pretty sure that he can't fix the numbers and the backlight on the cluster but needles might be the same as on SC.

nthach

OLT won't work on LS clusters because they are cold-cathode lit. Maybe he can design a LED replacement board, longer MTBF than CC.

retrodrive

I am talking about the needle not the cluster. Unless they are also cathode lit.

LexLS

Any info is very helpful CUMan, thank you .

I have already asked OLT, but he does not have any experience with LS clusters. I am going to point him to this thread so he help diagnose the problem.

To recap here, there are two separate problems with our clusters; the cluster backlighting (cold cathode lamps), and the needle lighting (also cold cathode lamps). The cluster backlighting can be fixed by recapping the circuit boards.

The needle lighting is what we need to figure out. I am pretty sure that the connection to the end of the needle just needs to be reestablished. The question is how to do this and what material to use. I have taken a few close up shots so everyone can see what I'm talking about. The black 3/4 tube that goes around the needle is cracked, it does not appear to be connected to the glass on the needle....hmmm...ideas?