Gave it a lot more juice and it powered up with everything warning lamp on the entire thing lit up. That'll be why it wanted 2 amps!
No message center though. The ignition live on the green wire didn't seem to do anything at all. Looking at the diagram that seems to be airbag related somehow.

As above I don't want to stick it in and have the becm overwritten with a much higher value and I've no idea what miles are currently on it. My cars on 195k, so it seems unlikely it would be higher, but you never know 🤣

Anyone know if the becm will automatically take the reading from the cluster, or are there additional steps which will allow me to power it up in the car and see what's shown? There's something in nanocom about odometer sync?

Anyone know if its possible to bench test an instrument cluster?

I picked up a cluster from the scrap yard. Wanted to power it on to check the mileage, so i've connected the two purples to 12v and the two blacks to ground. Set up a current limited supply of half an amp, and its pulling all of it and showing no signs of life.

Before i just crank up the power i wanted to check if anyones done this before and knows if it will even work? Does it need the serial comms to the BECM to actually come alive?

Been working on fixing my audio system, converting from "high line" to "midline" and replacing the door cards at the same time.

Ofcourse its slow going. Rear cards are in, but one of the plastic bushes that holds the handle to the door has exploded. Rear speakers also rewired, and 10uf filter cap added and thats all working as expected. Started on the front and discovered the tweeters built in filter cap is completely useless, so i'll need to fix that!

Managed to run the battery flat twice working on the car. Not sure exactly whats going on but seems like a few hours of opening/closing doors and the odd ignition cycle is enough to run it flat. For now, i'll keep attaching my bench supply while working on it as i dont want to ruin the battery completely.

you need to select "security learn" i think its on the next page?

you can sometimes tell by simply jacking it and spinning each wheel and seeing how it sounds. Especially if you compare side to side you might notice one feels or sounds rougher. however due to drag on the brakes and depending on how worn the bearing is etc its not always foolproof.

I dont think there are any bearings in the outer end of the front axle case? there is a plain section of shaft that runs in the oil seal, and otherwise its supported by the CV joint/wheel bearing itself.

Chrisp38 wrote:

I replaced the reg/brush pack on my diesel in around 1/2 hr, no need to remove the alternator and I'd never done one before. Just small bolts, no soldering.

Yeh some have removable brush packs, but the main rectifier diodes are still soldered to the windings.

I think i've got a similar bosch unit on the bench, i'll pop the cover off and take some photos when i get a minute.

I suppose its one of those tradeoffs, your spending £20 instead of £120, but if it goes wrong your now out several hours and £140.

my luck with rebuild parts for alternators has been limited. If the commutator or windings are shot (and i've been bit by both of those!) then you've spent hours messing with it for nothing. Newer alts also have the regulator/brush pack soldered into the windings so its not even a quick swap, its a lot of faff just to get into it, hours of messing to swap the bits and you get it all back together and it still doesnt work.

Years ago, it seemed the brushes would wear out or the regulator would fail relatively early in the life of the unit. Nowadays, the parts tend to last 20+ years and by the time any of it fails, the whole things basically needing rebuilt.

i need to check this out on mine.

Its always parked uphill and definately gets damp on the inside if its raining (though no visible puddles)

Thanks guys.

Not done any more yet, i need to get the bosch unit powered up on the bench and sort some basic code to take readings from it. Unfortunately my "bench" is currently the carpet in the middle of the floor of my study as i'm half way thru remodelling the room which doesnt help!

And yeah, it should be flexible enough to be able to run any MAF. i guess its just a couple of lookup tables in the code. Read input volts from the ADC, lookup airflow in the "input" table, then lookup the representative voltage in the "output" table and set the output. I guess we might add some interpolation as undoubtedly we'll end up between points, i would imagine there are functions pre-existing to do that part anyway.

The other option is a single table in the code, directly mapping input and output, and a supplementary excel sheet which you feed both tables and it creates the output table for you. I'll have a play with both options and see where it goes.

syncing the fob on mine required some dance with pressing the fob buttons while actuating the lock. I have a feeling later cars are supposed to be better/more automated at that process though

i dont think you can fully disable the immobiliser. All you can disable is passive immobilisation, where the immobiliser turns itself back on when the car has been sat for X minutes.

In your case, if it was locked with the fob, and that fob is no longer working, you basically have two choices, use the other fob, or use EKA.

Ive had it before where the fob battery cover has turned while the key was in my pocket, disconnecting the battery contacts and clearing the fob sync.

Damn that sounds like a proper unfortunate clusterfk. COVID and Brexit together have really hammered soo many small businesses.

Missing values are 2.5v and 5v

i just could not get the nanocom to capture the 2.5v point. I might reconfigure the DAC to output a constant 2.5v and see if that will give me a reading. I did get multiple readings for the 5v point, but it displayed 788kg/hr, which doesnt fit the curve at all. I suspect they've set full scale around 4.8v and anything beyond that is probably used to indicate a fault. In any case, 777kg/hr is around 270hp worth of airflow, so i dont think it'll ever be going beyond there in normal operation.

Had another go last night, and it was a frustrating hour fighting with the Nanocom. Seriously unimpressed with that POS tbh.

It refused to stay connected to the ECU when displaying the "AIR - IDLE" tab. you'd get 20-30 seconds at most before it would just stop updating. To get it to reconnect, you had to exit all the way out to the main screen and go all the way back in again. and every time you did that, nanocom stops logging. In the end i just used my phone camera to record the screen, and manually plucked the values out later by rewatching the videos later while sat in front of the computer. Ofcourse each time you start logging its in a random place in the sequence, so you need to do it multiple times to actually see all the figures.

Managed 14 of the 16 data points which when plotted in excel makes a fairly nice looking curve.

I then used the "trendline" function to plot a line and used the resulting equation to produce 256 data points from the curve. its not 100%, but its very close and i'm sure its good enough for an old V8! So we're getting somewhere. I'll post some of the data in a little while.

Bought some black leather door cards. Ofcourse the clever-sod that removed them has managed to break the drivers card. It'll probably be alright, but certainly is a bit annoying after finally finding a set.
Also bought a late spec cupholder and removed some more bits of trim to vinyl wrap.
I'll need to take some photos and get a wee thread going.

I remember using these guys years ago, always seemed decent, and tbh i hadnt actually realised they'd gone under. Anyone know the gist?

while it incorrectly says RHD, i'm pretty certain my 94 is laid out the same at the rear.

The flexi pipes come off the centre of the axle and go up to the left/passenger side, then the hardlines loop back around, run across the car and go up the drivers chassis leg.

Its been ages since i've been under it, but i do vaguely recall seeing the pipework and thinking "ah those are in the way of the second exhaust box/pipework". But it was a long time ago. Now i'm thinking about it, i also recall the someones fitted a later model axle without the proper bracket for the brake pipes, and the old bracket was jubilee clipped in place. I had intended to revisit that and probably switch over to the later style setup and repipe everything with new flexis. And i've instead ignored it for 5 years 😮

My remote doesnt work due to reasons i've never quite figured out. Plus, i only have one, with the wifes keychain only having a standard key blade on it.
As such i always lock with the key. As far as i can tell, it all works as normal. At one point i had a bad microswitch, so the car occasionally didnt "see" the unlock event from the key, If you noticed and unlocked again, it usually worked, but if you didnt notice and opened the door and tried to start the car, the alarm would go off and the car displays engine immobilised as you would expect.

My car is a very early model so i dont know if that makes a difference. I've noticed in Nanocom it says "Security Learn: NO" so i'm not sure if my car acts differently to any others. It definitely doesnt have passive immobilisation. I often leave it unlocked and it'll always start immediately without any key button pressing.

All i've figured out is that if you always use the key, it works fine, if you try and mix them, you run into issues. Specifically locking with the fob, means you cant then unlock with the key.

I've been contemplating fitting some sort of aftermarket fob system, but for now it works well enough with the key so its been ignored.

@jacckk - Thanks i'll take a look at that, is that why Nanocom shows "adaptive airflow -0.6"?

Clive, this was my initial thought. However to do that you need a known working (correctly!) MAF, and those dont exist ;) If they did then i wouldnt be doing all of this :(

All youd achieve otherwise, is perfectly replicating your faulty worn out 20AM thats not working properly!

yeah exactly, i'm hoping that either i can get a nice "curve fit" trendline that works with my 16 data points and extrapolate there, or i'll do some more passes with a tighter interval. Probably a bit of both. If the Nanocom will stay connected i can just get the arduino to cycle thru with a very small step size and log the whole series.

The bosch maf table is 512 entries long, so thats a voltage step of a bit less than 0.01v between each entry. I'm not sure how good the Arduino ADC is, but i guess if we can build a translation table thats at least 256 entries we should be pretty close, ideally we can do some interpolation between lookups too.

The wonky IAT is apparently quite common on GEMS cars, i've not looked into it too closely, but i will try to measure and take some readings there too.

The MAF should self compensate for all those things like you say, its measuring mass, not volume, i would hazard that the newer Bosch units are probably doing a better job than the 20AM though.

The lag between the kg/h and volts is definitely a nanocom issue (or perhaps just the ECU's diagnostic interface/protocol) and yeah, i would expect the ECU to act instantly to changes in MAF voltage. As for everything else, i really dont know. The DAC i'm using can apparently perform updates at around 6khz, which i would hope is plenty fast enough