90 740 Dash board light problem

The display lights on my 90 740 went out the other night. The lights for the
clock, speedometer, tach etc and the lights for the heater controls, ash
tray and shift control are dark.. I changed the fuse but that fuse #21 also
is for the marker lights and some back lights and they are all on. Any help
appreciated. Thanks

 

You need to check the connectors and wiring behind the dashboard. Fuse 5
supplies interior lights so will not be involved. The panel lights wiring
involves a couple of inline soldered joints in the loom behind the dashboard
(found by removing the knee panel or the instrument panel, then following
the wires from behind one of the switches). I think they are Blue and Black.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

Try wiggling the shaft of the dimmer rheostat and see if the lights come on.

 

This model doesn't have a dimmer rheostat.

on.

 

Are you sure? My '87 does, granted the '90 has a different dash but it
would shock me if it didn't have a dimmer.

 

Sadly, "PK" is mistaken. The instrument panel rheostat is shown below,
http://apps.volvocars.us/ownersdocs/1990/1990_740/90740_03.htm
(Pg. 8, No. 10)

AC

 

That's the older style dash like my '87 has, didn't they update it in '90?

 

No, not till '91.

To the OP: If you remove the cluster and join the red and blue wires
going from the circuit board to the dimmer together, the dimmer is out
of the circuit. The dash lights then come on full bright only.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Well since he thought it doesn't have a dimmer it wouldn't surprise me
at all if it just got turned down all the way while trying to set the
clock or something.

 

You got it! Not driving this car very often, my daughter turned the dimmer
down while she thought she was trying to reset the clock for daylight
savings. When I looked quickly at the dash I was looking for a dimmer near
the headlight switch. That little black post just blends into the dash. I've
only had this car for 13 years DUH!!!!
It has become easier to post the problem on this newsgroup than to give it
much thought.
Thanks to all.