Gauge Cluster

[mofocker]

Hello everyone. I've been searching and keep finding conflicting info on gauge interchangeability. I have a dead speedometer and temp gauge in a VDO cluster. I tried the quick tricks to fix but nothing works. My question is can I just buy any gauge cluster to replace mine with or does it have to be the same brand and same year? I see some have a little label on bottom right front corner, some are blue on back, some have words above the service lights, etc. Mine is a VDO with white back, no little label in front corner, no words above the service lights, and is from an 86'. Also and probably my best bet - if the gauge cluster isn't interchangeable, are the gauges themselves? Like can I buy any VDO cluster and just take out the two gauges off mine and replace with the ones from donor cluster? Thanks in advance for any help offered.

[Freakshow]

For the speedometer try replacing the sensor on your diff.

[mofocker]

Thanks. Tried that but no luck. Every once in a while it will jump up while driving and then die again. I'm pretty sure it's a shoddy solder connection somewhere behind gauge.

[Freakshow]

Your best bet would be to find the same year and model car and get one from the junk yard if it doesn't work you can return it.

[JasonC]

What year is your car?

[Semblance]

Motometer and VDO gauges are interchangeable. But the fuel gauges are different early/late, the tach should match your engine redline and the coding plug needs to be from the same year as yours (just use yours). But sounds like SI board trouble.

[mofocker]

I thought it could be si board at first but all the lights work and the service meter works fine. Gas gauge works and so does tach. The mph meter is possessed I think but it moves and works. The one thing I didn't think to do would be to check fuses... I don't mind buying a gauge as long as i can swap out the speedo unit and place Into my cluster, and if that doesn't work, then I don't know what's left to do but accept defeat. I do need a temp gauge to work. I feel a little unsettling not knowing if car is going to overheat or not.

[mofocker]

Oh and the car is 86' 325e

[Semblance]

The SI board is a bewitched part. It could still be affecting the temp gauge even if the rest of it is operating ok. ///GregsM on here repairs them. IIRC the SI board doesn't affect the speedo, so if it's not your diff sensor, i guess the next thing to do is swap gauges. I have a spare mostly-working cluster if you can't find parts locally, but it's a for a late 325i, so the tach and fuel gauge won't work in your car.

[Gregs///M]

Rarely do the gauges actually fail. Most cluster issues are old, blown fuses. Replace fuse 10, 12, and 21. Don't check them, just replace them.

Also make sure the 7mm nut is tight behind temp and fuel gauges. There should be two spring washers and two flat washers for those temp and fuel gauges. If those are missing, your gauge will be inaccurate or not work.

Cracked or damaged solder joints is another common issue too.

Swapping the gauges themselves rarely fixes anything.

[Gregs///M]

Oh, and if your SI board batteries have never changed, they are 20+ years old and surely dead. It will affect temp, tach, MPG gauges and service LED's. It can cause inaccurate gauges or them to not work at all.

There are only two versions of the E30 cluster, pre-1986 with 9 LED service lights and post-1986 with 7 LED service lights. Parts are interchangeable among the same generation only. Temp and fuel gauges are interchangeable among all e30 clusters.

[mofocker]

Thanks! I'm going to go get some fuses and swap 10 12 and 21. On the diagram I found it seems those fuses control quite a few things - all of which work fine. If the fuse was blown wouldn't everything else under that fuse not work?

[mofocker]

Ok so i changed all three fuses. 10,12, and 21. The diagram said all three were 7.5 amp but when i went to replace them only fuse 10 was 7.5, but fuse 12 was 30amp and fuse 21 was 15amp - i changed all three with 7.5amp fuses. Is that ok? Why would the other two be listed in manual as having 7.5 but have had the standard factory looking 30 and 15 amp fuses? Everything seems to work but should i expect something to blow out?

Also x 2, the speedometer still doesnt work.:hitler:

[fastnfurious7]

Many people replace fuses with whatever they have so if they are supposed to be 7.5 you're doing right by putting the proper rated fuse back in there. Send your cluster to Greg's///M for rebuild... you'll be happy you did.