IPD sale XeMODeX - Experts in Volvo Electronics
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy your stuff using this and it helps MVS!

weird dash malfunction

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

User avatar
Clemens
Posts: 1044
Joined: Thu Sep 03, 2015 12:34 pm
Year and Model: 96 855 R + 94 855 T5
Location: Austria
Has thanked: 73 times
Been thanked: 40 times
Austria
Clemens

weird dash malfunction

Post by Clemens » Sat Nov 02, 2019 11:01 am

A few months back the battery was quite empty I guess and after starting the 96 R after a shirt drive to back up into the garage a few random dash lights came on. I recharged the battery, all lights were gone.

Today in the morning it felt slowish on startup, thought batzery about empty from sitting for a week. (it is a Volvo battery, 3 yrs old). Drove for an hour, parked the car for 6 hours. Went to start again, turned over slowish, but fired up.

And then the dash was like a zombie. Lights on, clock working, turbo gauge working. No rpm, no coolant temp, no exterior temp, no speedo, no odometer, no fuel gauge.

Drove for 5 miles, started again, everything was fine. Is rgis a weird low battery or starter wire corrosuin issue or what else could it be? I doibt it is the ABS unit because this should not cause problems with fuel gauge, temp etc. Plus, I already fixed it twice.

btw.: wiggling the key while in zombie mode didn't change a thing.

Let the guessing begin ...


Summer: 1996 855 R
Winter: 1994 855 T5M
Donor: 1995 854 10V

User avatar
greg850r
Posts: 265
Joined: Thu May 03, 2012 5:06 pm
Year and Model: a long list
Location: Mo
Has thanked: 4 times
Been thanked: 9 times
United States of America
greg850r

Re: weird dash malfunction

Post by greg850r » Sat Nov 02, 2019 4:08 pm

I would load test the battery and charging system too. It sounds very much like a low voltage situation.
These users thanked the author greg850r for the post:
Clemens


05 Cross Country wagon
99 C70 Convertible
96 850R wagon
96 850T wagon
96 850 GLT 5spd N/A sedan
97 850R 5spd sedan
66 GTO 421SD 4spd
67 GTO 455 T400
02 Powerstroke 4x4
85 Yota 4x4
24' 454 Challenger
07 Softail Custom
02 Sportster Custom
Parts cars not included

User avatar
abscate
MVS Moderator
Posts: 18927
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 222 times
Been thanked: 738 times
Trinidad & Tobago
abscate

Re: weird dash malfunction

Post by abscate » Sun Nov 03, 2019 4:54 am

Have a good look at the battery and ground cables, including the joined connection at the starter.

If that’s all good, electrical part of ignition switch, part number...
These users thanked the author abscate for the post:
Clemens


Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW
Link to Maintenance record thread

User avatar
Clemens
Posts: 1044
Joined: Thu Sep 03, 2015 12:34 pm
Year and Model: 96 855 R + 94 855 T5
Location: Austria
Has thanked: 73 times
Been thanked: 40 times
Austria
Clemens

Re: weird dash malfunction

Post by Clemens » Sun Nov 03, 2019 12:29 pm

Thanks, I will take a look at the wires and the charging system. I guess the battery symbol only comes on if the charging system is really bad, not if it is starting to be on it's way out.


Summer: 1996 855 R
Winter: 1994 855 T5M
Donor: 1995 854 10V

User avatar
misha
Posts: 4010
Joined: Sun Dec 07, 2008 4:09 pm
Year and Model: '97 850 2.5 20v
Location: Serbia
Has thanked: 36 times
Been thanked: 96 times
Serbia
misha

Re: weird dash malfunction

Post by misha » Sun Nov 03, 2019 1:56 pm

Battery light will illuminate when there is a permanent fault with voltage regulator or with diodes....in other words....when there is no voltage output from the alternator.
Otherwise....if b+ cable or ground cable is bad it will illuminate only if charging output is lower than battery voltage.

For example....when the car use only battery voltage to keep running and no output from
alternator.

When i had a bad b+ cable and when i had 13.1v on battery terminals the battery light wasn't ON.
I guess that it's because i still had 14-14.2v measured directly on alternator.

After replacement of b+ cable i had the same voltage reading on battery terminals & alternator.
These users thanked the author misha for the post:
Clemens


'97 850 2.5 20v /fully equipped/ Motronic 4.4 / polar white wagon
'91 Citroen XM 2.0 SI /fully equipped/mandarine red metallic
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

Post Reply