Dash Meltdown on my 535i!

[John B.]

My wife called a few minutes ago to tell me that the dash had gone nuts as she was driving our 1990 (12/89 - 186K) 535i to work. Car is running fine but the gauges pegged, there was an error code message with a question mark & some of the lights at the bottom went out. She got to work ok but the speedo & tach are out with the needle resting at zero & the fuel gauge & coolant gauge are pegged.

Is this the common failure mode for the capacitor problem I read about on the E34 Website? Other thoughts? If it is the capacitor problem any tips on where to buy the correct parts & which ones to get would be appreciated?

[ScottyWM]

Probably easier to just replace the whole instrument cluster from a good donor. Move the chip from your old one to the new one. It's a pretty easy swap.

[Bill R.]

It can be one of the symptoms of the failure mode. I would give it a day or two and see if it goes back to normal first

[John B.]

I ran the check mode; holding in the black button & turning on the key. Speedo is still dead, both the coolant & fuel gauge are pegged full right but the tach is now working normally & I got all the small lights back. I'll try the battery cables off & jumpered reset in the morning.

[Bill R.]

You may just have a bad connection at the back of the cluster also, if you have any stabilant 22 i would take the cluster out and treat all the contacts on the back and the plug for the connectors also.... if you don't have stabilant then i would use some deoxit d5 available from most electronics places, Radio shack carries it i think

[John B.]

Thanks Bill, I've got some of the Deoxit d5. Can I pull the cluster out far enough to get at the connectors & spray them without pulling the steering wheel?

[Bill R.]

Not very easily, its much easier to pull the steering wheel.

[John B.]

Which means removing the airbag. Since it is over 20 years old I've thought about disconnecting or removing the airbag. If I want to remove the Airbag would I have to replace the entire steering wheel or can I use a center filler section from an earlier car? Would removing the A/B cause any electrical issues aside from the dash warning light staying on?

[ScottyWM]

It may be worth a try to remove it without taking off the steering wheel. What I did was make sure the steering wheel was adjusted all the way out. Then I drove the car so that the front wheels were on cardboard (or you could just lift the front end of the car so the wheels were off the ground). Kept the key in position 1 (2?) so that the steering wheel was not locked. Then as I removed the instrument cluster, I could easily turn the steering wheel to get the best position for the cluster removal.

[Bill R.]

John, i've seen many 15 to 20 year old airbags still functioning fine. I'd put it back in if it were mine. You'd have to use an entire wheel from another car if you get rid of it. I've seen some shady car dealers recover the steering wheel cover on cars that have triggered the bag, so you could do that if you don't want the bag any more.
It won't cause any problem removing the a/b other than the indicator light in the dash on your car.
Bags are pretty cheap now, i see them all the time at the junkyards , i picked up a door bag and a roof bag for an e46 coupe for less than 200, actually i think it was much less.

[John B.]

Tried the battery cable reset but didn't notice any difference. A good thump on the dash top got the coolant gauge & speedo working again but the fuel gauge stayed dead. Took it out for a drive & after a couple miles everything went crazy again with needles flipping all over the place & various warnings popping up before everything died completely once again. It does seem like a bad ground/connection somewhere so I guess I'll pull it out tomorrow & see what I find.

[genphreak]

If it isn't the connections, the capacitors are probably expiring... there are fix it threads on the 'Net to guide you if you feel like removing the cluster and getting handy with a soldering iron.

[John B.]

Just dug into the dash repair today. Had no problem pulling out the instrument cluster with the steering wheel attached. I removed the two bolts that hold the steering column up, pulled the steering wheel down about 1" & I had room to lift the cluster out on either side.

Getting the board out of the back cover looks like fun but I'll try the "clean up the connections" fix before I get serious about removing the board. As luck would have it my can of Deoxit is finally dead so I've got to see if I can find it locally or order some of the Stabilant through Napa.

[John B.]

Cleaned all the contacts & put it back together. Speedo/tach/vacuum gauge & what looks like all or at least most of the idiot lights work. No craziness or flashing messages while driving but the fuel/coolant & odometer functions are dead. Guess I'll have to dig deeper.

[John B.]

Just got power back yesterday after Irene passed through last weekend. Pulled the board & the big 1000mf 16v cap looks to be the problem as some brown smooge had oozed out the bottom & hardened. No luck at Radio Shack which is basically a cell phone store these days. If I strike out at the local electrical supply shop Monday I'll look for an on line source.

[John B.]

Ended up ordering what I could find on line but getting all 3 types of capacitors in the original configuration doesn't seem like it is going to happen. The big 1000uf/16v/105C is easy as it is a popular upgrade on all the Samsung LED tv motherboards when the original 1000uf/10v cap dies. All the original caps use a 5mm lead spacing which is difficult (impossible) to find in the 220uf/16v/105C & 22uf/40v/105C listings I looked through. 2mm-3.5mm is standard & finding 105C rated caps is also difficult in these sizes. Since they were only $.09 each I bought a 220uf/16v/105C cap that didn't list the lead spacing to see if it will work. No luck at all on the 22uf/40v/105c cap.

[Bill R.]

Hi John, i used the different lead spacing in 105C caps on mine without any problem , i just left the leads longer and had the caps sit a little off the board to make the leads fit. I also used a higher voltage rating since i couldn't find the originals either. Hasn't been a problem on any of them that i've done.

[John B.]

Good to know, I figured the 3.5mm spacing might work ok but was trying to stay stock. Where did you find the 22uf/40v/105c (or higher) caps? Did you use caps with 3.5mm spacing or go even tighter (2mm)?

[Bill R.]

The first time i did one was on my own car and we were able to get them from a local company called elliot electronics. After that i did some using caps from Mouser online that a customer had ordered. Haven't had to do one in a long time now , I don't remember the spacing ,i just remember having to bend the leads to fit as the stock hole position wouldn't line up.

[John B.]

I ended up going with 22uf 50v caps as they were readily available with the 105C rating. Hope to have them tomorrow or Saturday; received the 1000uf & 220uf caps today. Since I have a Samsung LED TV I bought a couple extra of the 1000uf caps as I will probably need one in the near future.

[John B.]

Replaced the 1000uf & 2 22uf caps but no change. Waiting for the 220uf cap as they sent the wrong ones initially but I'm thinking the problem lies elsewhere. After replacing those caps the fuel/coolant/vacuum gauges/odo were still dead & the LED module would go wacky & start the tach/speedo needles flipping. This morning I took the LED module apart & cleaned the screen & board contacts similar to what you see in the E39 pixel fix write ups. LED module output is now stable & no wacky gauges so far but I haven't taken it for a drive yet. ODO functions are back but fuel/coolant gauges are still out.

I read something on the E34 website about the Coding Plug getting "corrupted" & causing the same gauge failure I'm seeing. Is there any fix such as removing/reinstalling the C/P or would it have to be replaced? What corrupts the C/P? Could the LED module/gauge wackiness have damaged it? Bill???

[Russell]

Interesting discussion as I have the LED module randomly flaking out with then going blank. Works fine some of the time. Bought a used cluster off a 95 540. May try to replace the cluster. However, I am a bit concerned over the airbag as well.

[ScottyWM]

That's why I replaced mine. You should be able to pull the cluster without removing the steering wheel and airbag - I was able to do it on my '93 525. Make sure you have the steering column adjusted all the way out. It's tight, and it helps to be able to turn the steering wheel as the cluster comes out (raise the front end or drive front wheels onto cardboard), but it came out and the new one went in with very little trouble.

[John B.]

I was able to remove the cluster on both our 535i & the 95 Touring without removing the steering wheel. Just took the car out for a test drive; no more wacky gauges, fuel/coolant still dead, LED/ODO went off & back on twice with a chime each way & each time resetting the trip meter. Tach & speedo are working fine so at least it's driveable again but far from fixed. With the fuel gauge out it would be nice if the trip meter didn't keep resetting.

Forgot to mention that all gauges run through the "test function" normally.

[Bill R.]

John, you replaced all the caps.... one of the symptoms of mine when it went bad was that the first time i hit the brake pedal on a cold start the voltage drop from the brake lights would make the odometer reset and the chime would bong once.... I figured the caps weren't storing power and the voltage drop was making the coding plug memory and other functions on the cluster go wonky. After changing all the ones in the pic on Bruno's page here (http://www.bmwe34.net/E34main/Maintenance/Electrical/Capacitors.htm) i had no more problems. Others had problems with the coding plug wiping out the fuel and temp gauges.

[John B.]

Well I've replaced all the caps on the large board & the small tantalum cap on the LCD board. End result is that the fuel & coolant gauges are still dead & after a 15 mile drive all the craziness of flipping/dropping needles, random chimes & flashing warnings returns. So replacing all the caps, cleaning the LED contacts, ect. accomplished absolutely nothing.

If I look for a used instrument cluster I imagine it has to be from a 2/89 thru 92 coding plug E34. The latter style non coding plug cluster isn't going to work?? Even with a good used cluster if my coding plug is corrupted will I have to spring for a new one or can I use the plug that comes with the used cluster? Typical cost of a good used cluster?

[John B.]

Looks like complete instrument clusters are dirt cheap! Should have checked pricing before I ordered any caps. Question: One vendor has 4 clusters from Automatics; no 5 speeds. Is there any difference between an instrument cluster from an Automatic & one from a 5 speed car besides the coding plug?

[myles]

There are several different clusters for E34s. Just make sure the color of the plastic back is the same. Old E34s have grey, then newer ones have a white back and the more recent ones have a blue back. Then some of the basic models have a different color again. Move your coding plug into the new one and you're away.

Auto/manual doesn't change the cluster, just the data stored in the coding plug.

[John B.]

Thanks for the reply. From what I found out today only a cluster from a 535i/735i will work. I have a 535i "Auto" cluster on the way as I couldn't find one with a 5 spd plug.. I guess I'll find out if my coding plug was corrupted or not.

[Paul in NZ]

good luck!

[Bill R.]

John, check your hotmail email address. I sent you some pdf files from the older tis that has useful info on dash clusters and diagnostics. The file size limitation on pdf's here is to small to upload each one here.

Bill

[Russell]

John, check your hotmail email address. I sent you some pdf files from the older tis that has useful info on dash clusters and diagnostics. The file size limitation on pdf's here is to small to upload each one here.

Bill

Bill.
I am intereeted in this information as my dot matrix display will often scramble and the go blank. Other times it is perfect. Everything else works fine. Not sure what I need to do. I did buy a complete working dash cluster from an auto 95 540i. My e-mail plan1@insightbb.com

Thanks

[Bill R.]

Russell none of the bulletins i sent to John would apply to your issue. I remember seeing something about it in one of the older tis's, Next time i'm on one of the computers i have an older tis loaded on i'll see if i can find it. I have each older tis loaded on a differnet computer since each time you install a new one it wipes out the old one.

[John B.]

There are several different clusters for E34s. Just make sure the color of the plastic back is the same. Old E34s have grey, then newer ones have a white back and the more recent ones have a blue back. Then some of the basic models have a different color again. Move your coding plug into the new one and you're away.

Auto/manual doesn't change the cluster, just the data stored in the coding plug.

Received the used cluster but it has the blue cover & a production date of 8/91. Parts list shows a different coding plug & circuit board for this cluster as compared to my 12/89 cluster. Can this be used or do I need to start once again?

[Russell]

thanks I appreciate the help.

[myles]

If that's come from a 535iA and yours is a 535iM then it should basically work, but you won't be able to swap the coding plug into it, so it will still think its in an Auto and will probably give you a check control error 'trans prog'. Otherwise it should basically work.

If you want a perfect match, grab a white backed cluster out of ANY E34/E32 with check control and swap only the PCB with your cluster. You should re-use your gauges (they might use different scales in the donor car and should typically stay paired with your coding plug) and reuse your coding plug.

I've had a fair bit of experience trying to piece together the correct working cluster for my car. When I bought it (535iM) it had a cluster from a 735iLA in it and I had to slowly learn how to get it to work correctly. I was lucky enough to never have a hardware fault so I've never had to try to repair a faulty one, but I've been through several clusters to get mine working.

[John B.]

PCB = Conductor PLate/Main Circuit board? Since the cluster with the blue cover uses a different board with certain functions in different locations and BMW changed the front wiring harness at the same time I'm guessing that the various pins for the harness connectors may have different functions so I was hesitant to plug it in.

The supplier is taking it back but doesn't have an early cluster & I'm not having much/any luck finding an early 535i cluster. How does the 90 525i cluster differ from the 535i/735i cluster?

[John B.]

Curiosity got the better of me & I hooked up the 91-on blue back cluster as all the pins matched up to my old cluster. Everything worked fine & no faults or warnings when I started the car. There is an S (sport?) in the shift mode readout but other then that everything seems to be working correctly. Looks like I can at least drive the car while I look for a cluster that will accept my coding plug.

[John B.]

My wife called from work yesterday to tell me that none of the gauges in the dash cluster I'd installed 4 months ago were working. This followed several nights of extremely cold 0*F temps so I suggested she try two possible fixes well known to any skilled amateur mechanic. Rap on the dash cover with your knuckles or give the top of the dash a good thump. She opted for the dash thump & I'm very happy to report all gauges are once again working. Hopefully they remain in that condition until more moderate temps return when I will pop out the cluster & check the connections.

[6670charger]

I'm having a similar issue with the gauges in my 518. I recently replaced the middle of the three larger light bulbs as it wasn't working. I used a used light bulb. The bulb still doesn't illuminate, but now my gauges go crazy in the morning when I turn on the light switch. Later in the day, or after I've driven the car for a while, it seems to be fine. The only thing I did was change the light bulb, so I wonder if that bulb is maybe causing some sort of continuity problem? Haven't had an opportunity yet to try a different bulb to see if that solves the problem. The only other thing I can think of based on some earlier comments in this thread is that maybe something needs to be reset after having disconnected the battery a couple of times?

[6670charger]

My issue ended up being the large center light bulb in the cluster. Must have had a short in it. Put a good one in and now everything seems to work fine.