A80Q mileo dead??

[spaarky]

1988 80quattro (1781FI - DZ engine) has been my daily for 12 years now & has treated me real good, but due to redundancy, subsequent lack of funds & my ignorance, is now feeling its age in a few areas

oddest problem I've noticed today is that the mileometer & trip meter have stopped working - speed needle still works ok (except when is sticks in the winter, but that's another story), but the mileage don't change, regardless of how far you drive - same for the trip meter - is that even legal ..?

in an older car, I woulda thought the speedo cable had snapped since I have had some screeching noise from front end over last few weeks, but speed needle is still working fine

have looked at haynes manual - as most of you know, they don't do a manual for the quattro - and the wiring diagram (for 2.3 -7A engine models, whereas mine is 1.8 DZ engine) suggests an electronic speedo sender, but can't find any info anywhere about what drives the mileage & trip. haynes about as much use as tits on a fish, as usual

anyone got any experience/ideas ? am I being a dummy & missing something obvious ? sadly can't afford to replace parts unless absolutely sure to fix. any thoughts much appreciated

[spaarky]

apologies if the above is posted in the wrong forum, but can't see how to move, or even which other forum would be more appropriate since not sure if a mech or elec prob

[Puglife]

Firstly what shape is the 80 quattro? i'm guessing at type85, in which case it will most likely be electrical speedo sender. This is on the side of the gearbox diff casing (from memory its just above the passenger side driveshaft output flange.)

IT could also be a problem within the instrument cluster where speedo sender is giving a reading from diff worm drive, but the tripmeter isnt picking up the signal for distance..

[Ben]

If the speedo is still working then the sender is too, I had a speedo to pieces a few weeks ago and it's a self contained unit with the milometer driven from a stepper motor. I'd suspect a soldered joint has become dry inside the speedo unit, if you have a soldering iron then you can run it over any suspect joints, if you want to replace just the speedo unit then beware as Audi have different versions of the binnacle and the innards aren't interchangable.

[spaarky]

many thanks ben & puglife - has bin a real struggle to get any info on the car or a decent workshop manual & the haynes one is almost a total waste of space. web don't seem to be much help either so far

it's a B3/Typ89 A80 body with a small boot spoiler & quattro - not sure if it's relatively unusual or if they didn't last long, but I've only ever seen one other similar on the road in 12 years & that was a quick glimpse a coupla weeks ago. I have bin lookin - this is my second audi & my old man is on his 5th since the late 70s. if it's unusual, that's probly why I can't find any info anywhere

I thought the same as ben - if there's only one sender for all speedo functions, and the speed needle works, then presumably the sender is good & it must be a problem with the mileage function in the speedo unit, but am just guessing. is it common for solder joints to dry out/break contact after a few years ? I can solder no prob, but can't afford to get another complete speedo unit, especially if main dealer is the only source - don't even wanna think how much that might cost, or even if they are still available

if mileage is driven by a stepper motor inside the speedo, do you think it possible that a 2nd hand stepper motor might fix it if available somewhere (?), or is it a case of trying the solder and if that don't work, next step is a whole new speedo unit ? sorry for all the questions, am looking for cheap straws to grasp

many thanks for your help, any & all advice much appreciated

[Puglife]

I have a speedo unit from an Audi 90 type 89 here. I'm not that up on the type89 layout but i can certainly get some photos of the innards for you if its any help?

[spaarky]

puglife - you're a star - any photos would really help - it's my only car & daily driver, any info I can get before pulling it all apart would be crackin

my clock layout (left to right) is small temp gauge, large tacho with integral (& broken) digital clock, large 135mph speedo with mileo & trip meter, small fuel gauge. speedo also has the number 893 190 at the very bottom under the MPH if that means anything to you (?)

[msh]

It isn't electrical fault.
1988. means it's B3. So u can get instrument cluster from Puglife and install from it speedometer clock. Only it, and not whole instrument cluster, because there is difference in tachometers. Fact that A90 have 260 kmph speedometer and A80 220 kmph speedometer [calculate miles for yourself, i'm lazy] doesn't mean anything at all, 260 kmph speedo will show the same speed when installed in place of 220 kmph speedo.
Fault is very simple - there is little plastic gear in odometer that gets damaged and stuck. I once repaired such speedo because I had other speedo which had died electrically but mechanically was ok, so I used gear from it. Otherwise just replace speedo clock or whole instrument cluster. And don't install whole instrument cluster from A90, otherwise u will ask "why my tachometer shows so high revolution count?"

[spaarky]

cheers, msh - good to hear from ya - how are things in sunny latvia ? I know you know your stuff, so several points for ya:

1) puglife seems to be a crackin bloke, but his spares are his own & given his avatar I suspect that the A90 speedo he's had apart recently isn't a spare, but that from one of his main cars so I can't presume any parts coming my way, esp since I have no £

2) you reckon that any B3 A80 or A90 speedo will work with the stock A80 sender - probly good news for me buddy, if I can find parts for either; plus news that the A90 speedo will work with no problem in A80 with stock sender, but rev counter will not

3) little plastic gear that gets damaged/stuck in odometer - can this gear not be freed up/fixed ? my history is with old cars, mainly old vw, so am used to having to fix the 'unfixable' and I am happy to have a go at anything rather than just replace. if there's a way I can fix it without having to replace any parts I will be a much happier man - I don't really want to change the whole speedo, just wanna fix it so that the odo function works again - if it's a mechanical part that's broke, surely it's fixable?

[Puglife]

I am actually a right Tommy WAT just kidding.

My speedo and odometer is all electrical and i suspect yours will be too. Worm driven odometers are cable driven speedo specific in most cases. And the worm drive, as stated, tends to fail meaning speedo still works but the odometer wont clock up.

I have a speedo unit in front on me so i can get you some photos of the PCB and odometer motor drive. I cant however confirm its same as yours.... The gearbox end has the sensor i previously mentioned and this will feed the speedo and odometer units. There are four pins to the speedo unit and i'll try get some info down on each and its corresponding wire colour if i can find the info.