I am having a problem with the speedo in my MondialQV, 1st, it is reading a little fast, is there an easy home fix to sort this out (its about 10% fast) 2nd, the odometer has stopped working suddenly, now the tricky thing is the service light still works, the service light is 'driven' from an impulse in the odometer to come on every 5000kms, now why would this function still opperate on the odometer side and the actual odometer not work, Im a little puzzled by this, any help or thoughts would be greatly appreciated (the service light has only just come on, this is how I know it is still functioning)
This may not help much but ...... There is a thread in here where one of our resident smart guys completely took a speedo apart, documenting how he adjusted it, and put it all back together with pics. If you find that thread, it MIGHT just answer your question. Sorry I cannot be more specific.
Allan, Take the speedy out and his front glass of. You can pull out the needle gently with you fingers. Replace the needle completly at point zero. Reinstal and make a spin to see if there are changes. With the odometer I can'nt help you out,... Guido
Ill have a go at fixing the speedo, but the odometer is still a mystery, if that has stopped working, then surely the service light that is connected via the odo would stop working as well, this leads me to believe there is a signal to the odo, but its just not turning
If he does that, the speedometer will read 10 MPH no matter how fast he's going. There's a little peg in the speedometer face that keeps the needle from dropping below 10 MPH.
there is no peg that stops the needle from going down, I have moved the needle and gone for a test drive, checking the speed against a TomTom One XL gps the speeds are, 60km/hr on gps- 62km/hr on gauge 80km/hr on gps- 83km/hr on gauge 100km/hr on gps- 105km/hr on gauge Im reasonably happy with that result, but the odometer still puzzles me
Well, you got pretty good results there Allan. I've learned that the Mondial speedometer differs from my GTB unit. Barry
Allan, thats a very good result. I would leave it that way. With new tyres the result will be a bit different in comparing with used ones. Guido
1. All early 1980 cars read 10% high except for a few which don't. Back then, there was talk about a conspiracy making you think the mileage was... or the speed was... anyway it was done and documented in some car magazines and no one has ever a good explanation manufacturers would intentionally do it. 2. The speedometer and odometer (and probably your service thingy) are run off an integrated circuit. They aren't mechanically linked, and being electronic they can fail any way they want, to cause the most confusion. Around here we send to the gauge to Palo Alto Speedo in California...you must have an equivalent repair facility down under.
what is confusing is the service light is operated by the impulse generator of the odometer, so if the service light is operating normally, I would think there is a signal to the odometer, then why is the dial on the odometer not turning
You are assuming the since evidence of the signal exists, that it is reaching the odometer solenoid. Bad wire is a bad wire. Or the solenoid itself could be bad. Or the odometer mechanicals could be bound up. Without having technical manual for the gauge and without having it open and under a glass, you can do nothing but guess. And without knowledge of how it works, your guess will be limited to your previous experience fixing speedometers which probably doesn't help either. If you really want to fix it yourself, do a web seek for the technical manual and go from there. And someone mentioned a previous thread about r&r with pictures. (r&r=remove&replace). These things are used in many euro cars with higher production numbers, so I'd try the MB or Porsche forums first.
I pulled the 80 mph peg on my 82 mondial and made pencil marks for higher speeds on the face Far a bit i thought the car was only going 80 when tach mathe said 100+ thata could get me in trouble
