1991 940 - Short in circuit of fuse #5, key-in chime bings non-stop - FIXED! TWICE!

khnitz · Jan 19, 2011

I've been trying to track down an issue in my (now my step-son's) 1991 940 GLE wagon. At some point, the door chime started binging all the time (whenever the key was in the ignition, whether it the ignition was on and the engine was running or not - the doors are closed). Also, the #5 Fuse kept popping...instantly, as soon as a new fuse was put in.

It took a bit before I had time to start digging into this deeper, but the schematics in my Haynes manual have not helped. The wire colors int he schematic do not match what is coming out of the fuse panel. These are GRN/RED wires on the #5 fuse circuit, which is for the radio. interior lights and other thigs. There are 3 leads coming from the #5 circuit on the fuse panel, 2 of the leads are single-wire, and one has two wires out of its female spade connector.

The single-wire leads measure as a short to GND, but the double wire lead read OK. I plugged it back in (and left the other 2 disconnected and taped up, and a new fuse can now be installed, and it doesn't pop. However, if I insert the key in the ignition, the warning bing is still there all the time when running.

Since the schematic I have isn't helping, does anyone out there have a similar issue they've fixed? Any BTDT advise? I'm trying to figure out where to check next for issues/shorts.

Thanks,
Karl in Johnsburg, IL

gdill2 · Jan 20, 2011

khnitz said:
I've been trying to track down an issue in my (now my step-son's) 1991 940 GLE wagon. At some point, the door chime started binging all the time (whenever the key was in the ignition, whether it the ignition was on and the engine was running or not - the doors are closed). Also, the #5 Fuse kept popping...instantly, as soon as a new fuse was put in.

It took a bit before I had time to start digging into this deeper, but the schematics in my Haynes manual have not helped. The wire colors int he schematic do not match what is coming out of the fuse panel. These are GRN/RED wires on the #5 fuse circuit, which is for the radio. interior lights and other thigs. There are 3 leads coming from the #5 circuit on the fuse panel, 2 of the leads are single-wire, and one has two wires out of its female spade connector.

The single-wire leads measure as a short to GND, but the double wire lead read OK. I plugged it back in (and left the other 2 disconnected and taped up, and a new fuse can now be installed, and it doesn't pop. However, if I insert the key in the ignition, the warning bing is still there all the time when running.

Since the schematic I have isn't helping, does anyone out there have a similar issue they've fixed? Any BTDT advise? I'm trying to figure out where to check next for issues/shorts.

Thanks,
Karl in Johnsburg, IL

One or both of the two wires you taped has a direct short somewhere.

What items do not work when this fuse is removed?

Do you have a multi-meter?

George Dill

khnitz · Oct 24, 2011

I'm reviving an old thread here, but this issue is still a problem, and I've just been letting my step-son drive around without the radio working, etc. We couldn't solve the "constant door chime" issue (temporary fix was just to pull the blue relay/chime box), but I started looking into that again some more yesterday, and I want to get the fuse issue resolved, too.

Next thing I'm going to check on the door chime, based on some searching, is to check the condition of the dome light bulb, and the interior lighting fuses. I've read where the seat belt warning chime will also go off if either of those is bad.

Then I'll have to start tracing what's happening on the #5 Fuse circuit.

I do have access to a multimeter (sorry for the late response, George) and have a solid vehicle electronics background, so that won't be the issue. Mainly, it's getting the time to look at it ;-)

khnitz · Oct 31, 2011

This one is SOLVED. There was a short in the circuit for fuse #5, for the interior lighting. It was in the wiring to the light on the vanity mirror in the passenger-side sunvisor. The wiring comes down the a-pillar and then behind the glovebox to a 2-pin connector. For some reason (don't know if it happened as part of a previous repair, or from the factory), that wiring was looped tightly around another harness behind the dashboard. Over time it wore through the insulation on the wires and they shorted together. Once I unplugged the connector for the visor mirror lighting, then everything returned to normal. I will be replacing those wires as part of the repair.

This makes sense, as the vanity mirror lighting is wired off of the dome light circuit. And, a failure in the dome light circuit triggers the seat belt warning chime, too.

khnitz · Nov 3, 2011

I repaired the shorted section of the wiring up to the passenger-side visor vanity mirror light and re-installed the visor, radio and glovebox last night. Everything is functioning great again. And best of all, no more Bing! Bing! Bing!

khnitz · Aug 4, 2012

The Bing! Bing! Bing! came back again a few months ago...Fuse #5 was blown again, so out came the blue relay/chime again until I could look at it with my step-son...which was today.

This time around, I started at the dome light and vanity light again, looking for a short. I could measure the short (between the GRN/RED and Ground), so I started trying to ohm-out individual lines to the lights. We pulled the fuse/relay out of the center console and started with the 3 points where GRN/RED lines terminate to the Fuse#5 power.

Long story short, this time around it was a short in the power radio antenna motor (it's a wagon, btw). My guess is that the motor or relay finally shorted after prolonged use because of the stiff/stuck antenna mast. The Power Antenna motor is run off of Fuse#5, too. The Haynes manual I have has unclear or incomplete wiring diagrams, as it is difficult to find everything powered off of Fuse #5 from them. So, I used the information in the owner's manual to understand what else is run off of Fuse#5. When I read "power antenna", that got me thinking to all the trouble we had with the old one and that it was likely the source.

We replaced the power antenna unit with one from a fairly clean 740 wagon that we found in the local u-pull-it junkyard. At the same time, we grabbed the PS front power window motor, as the one in ours had stripped its internal gears (the motor would turn internally, but it would not drive the sprocket to turn the window up and down). With the updated antenna motor assembly (actually looked like it was a Volvo replacement part anyway, from 1999...not bad) we also installed a new antenna mast/cord.

It's all buttoned up again, and the Bing! Bing! Bing! has been silenced once more!

John2x240 · Aug 5, 2012

Haynes books these days are nowhere near as good as they were a few decades back; they try to cover too many models today vs. the one or two models that they used to cover. Bentley manuals are much better, but they're not perfect. Try looking at this for info on your 945: http://www.k-jet.org/documents/greenbooks/900-series/

khnitz · Aug 6, 2012

Thank-you, John. Looks like the diagrams in the links refer to the later 9-series with the fuse panel on the side of the dashboard. Our 940 still has the fuse and relay panel behind the ashtray in the center console stack. Still, there's really useful information in those links!

So far, so good on the weekend's repairs to the Volvo

khnitz · Aug 14, 2012

And, apparently the fuse has blown again. I'll learn more about it tonight.

And, the car is hunting for gears now. Hmmm...

gdill2 · Aug 15, 2012

khnitz said:
And, apparently the fuse has blown again. I'll learn more about it tonight.

And, the car is hunting for gears now. Hmmm...

Does the ignition keyring have a bunch of stuff hanging on it?

George Dill

khnitz · Aug 15, 2012

There isn't a lot hanging off of the ignition keyring.

I looked at is some more yesterday evening. I found that the recently replaced power window motor does not seem to be working now (this is on the Fuse#5 circuit, so it could be a culprit) and the fuse inserted for slot 5 was 10 Amp (it should have been a 15 Amp).

But probably more likely the issue, I found that the line to the passenger visor vanity mirror light would vary in resistance when moved, even slightly. This makes me think that although, earlier, I had fixed the issue with the short in the wiring to this light that sits behind the glovebox, that there still is an issue where the wires pass through the hinge of the visor.

I had my step-son unplug that light (behind the glovebox) and I also unplugged the radio antenna motor. I'll have him drive it around for a while and see if anything else pops up again.

As for the stumbling, I'm noticed oil around the distributor housing at the back of the cylinder head, so my thought is to replace the distributor seals, cap and rotor (was last done about 30k miles ago).

gdill2 · Aug 15, 2012

With the car at warm smooth idle and everything turned "ON" (car in D and foot on brake) wiggle the ignition key in all directions (including in/out) but not enough to kill the engine.

Note any changes in idle, lights, blinkers, etc. when wiggling the key.

If no changes the igniition switch should be ok.

Consider a separate keyring for the ignition key.

George Dill

khnitz · Aug 15, 2012

I'll try that tonight, George. Thanks!

khnitz · Aug 16, 2012

Hi George, I am test driving the car today. Moving the key around with the engine warm and idling has no effect tied to the movement of the key. It just seems that every 5-10s the idle drops a 200rpm or so and then bounces back up. I wonder if the throttle position sensor or something similar may be at fault on this one. I haven't cleaned the throttle body in 30k miles or so...maybe that would do it.

Also noticed that the turn signal can stop at times. Ex: sitting at a light waiting to turn left... click, click, click, stop. If I turn the blinker off and on again, then again: click, click, click, stop. I wonder if I need to open the steering column and clean the contacts on the turn signal stalk switch...

gdill2 · Aug 16, 2012

With the engine at warm idle unplug the mass air meter and note any idle changes.

Little or no change could mean bad mass air meter and/or ECU. Also could be coolant temp sensor. Dump the codes lately?

Might change out the hazard flasher also.

George Dill

khnitz · Aug 17, 2012

I had the car for the day, as I stopped by a friend's after work who had the tools to top-off the A/C - it's blowing cold again, now. Loses about a pound a year.

Several issues that my step-son and I will have to address in the coming weeks (he's let too many little issues stack up):
1) the lumpy idle - we'll try the steps you mention first, George
2) the car had short periods of stalling that appeared to coincide with larger bumps from the road. Given everything else we've replaced in the last 30k miles, I'm leaning towards having to replace the fuel pump.
3) the pass-rear door lock can be a little sticky, so it doesn't always lock with the central locking
4) Fuel gauge is out - this is part of an update to a '92 instrument cluster to fix a broken speedometer/odometer before. I've got some figuring out to do on this
5) Turn signal stopped...only on left turns. The hazard flasher sounds right, George, as wiggling the turn signal stalk while it was stopped did not make a difference. It was only after turning it off and back on that it might flash again.
6) speedometer occassionaly stops reading - so we have to look at the connections at the rear diff speed sender again
7) dump the codes for the Check Engine light

That's about it for now. Plenty on the to-do list.

gdill2 · Aug 17, 2012

"...the car had short periods of stalling that appeared to coincide with larger bumps from the road..."

Bad motor/trans mounts allow the engine to move about causing bare wires and/or poor electrical connections to short/lose contact.

George Dill

John2x240 · Aug 17, 2012

This may help with the speedo: http://cleanflametrap.com/speedo.html There's another of Art's odo/speedo which I can't find right now; when I find it I'll post it.

khnitz · Aug 22, 2012

Hi John, thank-you for the link. We haven't had a chance to look into the speedo trouble more, yet, but we'll get there!

1991 940 - Short in circuit of fuse #5, key-in chime bings non-stop - FIXED! TWICE!

khnitz

gdill2

khnitz

khnitz

khnitz

khnitz

John2x240

khnitz

khnitz

gdill2

khnitz

gdill2

khnitz

khnitz

gdill2

khnitz

gdill2

John2x240

khnitz

Top Contributors this Month

Recommended Communities