Dashboard Test !!

From CEM to VEM, from LED to lightbulb and more. If you have an electrical problem, like a broken info-centre, search for answers in this category. This is also the place to be when you expect the problem to be of an electrical nature...

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motorecycle77
480 Newbie
Posts: 5
Joined: Sun Jul 25, 2021 7:40 am

Dashboard Test !!

Post by motorecycle77 » Fri Dec 10, 2021 8:52 am

Hello everybody, i have a problem with the odometer and i want to test the dash with a tester, i see on youtube a lot of video for test the odometer but i can' t understand what are the connections to make between the tester and the dash. This is the situation, backlight ok revcounter ok multifunctionboard ok, odometer death
Sorry for my bad english

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dcwalker
480 Is my middle name
Posts: 1522
Joined: Sun Sep 16, 2012 12:30 pm
Location: York

Re: Dashboard Test !!

Post by dcwalker » Fri Dec 10, 2021 9:12 am

Hi Motorcycle77

If your only problem is the odometer is not working, then you do not need a dash tester.

The problem will be a broken odometer cog. You will need to get one, strip down the speedometer and replace it. Not complicated just a bit fiddly.

There is stuff on here about it - I'll try to find it for you :) Found it - see this thread viewtopic.php?f=24&t=35684

David
Current: 1994 480 GT, 1996 460 CD & 1997 440 LE with lots of optional extras & 2007 V50 SE Sport
Previous: Celebration 331 (re-homed with Richard S), Celebration 467 (returned to Martin Mc); Celebration 346 (re-homed with Alan480); Celebration 269 (scrapped abandoned project), Celebration 73 (sold on after 6 years), 1992 ES, 1988 ES - and numerous other non-480 Volvos!

motorecycle77
480 Newbie
Posts: 5
Joined: Sun Jul 25, 2021 7:40 am

Re: Dashboard Test !!

Post by motorecycle77 » Fri Dec 10, 2021 12:33 pm

Thank you very much but how can i know if the problem is the cog broken or if the problem is on the sensor on gearbox or if the wiring between gearbox and the dash ?

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dragonflyjewels
480 Is my middle name
Posts: 1584
Joined: Sat Dec 18, 2010 10:38 am
Location: Norfolk

Re: Dashboard Test !!

Post by dragonflyjewels » Fri Dec 10, 2021 1:13 pm

If it was the sensor or connections, the speedo would almost certainly be dead as well. Just the odometer is unlikely to be anything other than the cog.
Sylvia

Snazzy - 1993 Paris Blue ES red dipstick 2.0i bought 2001
Lethal Lily - 1991 White Turbo
Paris the Unicorn - 1991 Paris Edition
hubby has
Sven - 1994 Racing Green GT
Evil Eva - 1992 Paris Blue Turbo

no previous 480s - can't bear to sell any

motorecycle77
480 Newbie
Posts: 5
Joined: Sun Jul 25, 2021 7:40 am

Re: Dashboard Test !!

Post by motorecycle77 » Sat Dec 11, 2021 3:23 pm

So the odometer have another signal to go ?

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jamescarruthers
480 Is my middle name
Posts: 2501
Joined: Mon Jul 07, 2003 3:19 pm
Location: Cambridge

Re: Dashboard Test !!

Post by jamescarruthers » Sat Dec 11, 2021 3:42 pm

Does the speedometer needle work?
1987 Volvo 480 ES, 507274, 217 - Red (Ness)
2006 Citroen C6 Exclusive 3.0 petrol/LPG
2008 Mini Cooper convertible (Mau)

Previous 480's:
J123 CFU -- ES
J449 MNL -- ES auto
D864 CPV -- ES
L691 JFC -- Turbo
F70 MNR -- ES
H858 FGV -- Turbo auto
E981 KHM -- ES (509849)

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brinkie
480 Connoisseur
Posts: 857
Joined: Mon Apr 21, 2014 11:20 am
Location: The Netherlands
Contact:

Re: Dashboard Test !!

Post by brinkie » Tue Dec 14, 2021 4:02 pm

The electronics of the 480 speedometer work as follows:

- a sensor (pick-up coil) in the gearbox senses passing teeth of the gears
- electronics in the speedometer detect this and create two signals
-- 1. a PWM signal for the speedometer needle and infocenter computer
-- 2. a stepper motor control signal to drive the odometer gears

When the odometer is dead, it is in 99 out of 100 cases (yes I have repaired that many instrument clusters :lol: ) a broken odometer cog. These deteriorate with age and will eventually break. In approximately 1 out of 100 cases the stepper motor is dead.

When odometer and speedometer are dead, it is in 99 out of 100 cases a cold solder joint on the main board.
Robert.

Present cars: 1994 Volvo 480 GT 2.0i, 1999 Volvo S70 2.5 Europa, 2010 Volvo V70 2.0F Momentum

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