Light bulb indicator comes on only when coming to a stop?

[98T5]

V940

My light bulb indicator came on, flashed a couple times and went away. Now it's back but only when I come to a stop or coming to a stop.Fuses and relays all snug in their sockets and I checked all the bulbs in the back and they check out fine. even swapped out a couple that looked suspect. still get that bulb indicator. any ideas?

[oldschoolvolvo]

so you had someone step on the brake for you and verify that all the brake lights are coming on?

when you say that "it only comes on when you are coming to a stop", do you mean that it only comes on when you push on the brake pedal?

[JohannReinhard]

I had this issue before with my 940 GL. You've done everything I have, save for two things.

1) Remove the wiring harness from the bulb bracket by disconnecting the wiring at the bracket. If it's badly seated, vibration and other movement in the body can make the connection work itself loose. Reseat it and test it again. I've seen brackets work loose over time, most annoyingly when I went in for inspection.

No dice?

2) Check for corrosion products on the terminals. Grey and dusty is okay, not preferable, but okay. Green or red terminals indicates moderate to heavy corrosion, which should be cleaned to restore proper functionality. A very fine piece of sandpaper (1500 grit or higher) can work, but I prefer to use Deoxit and a swab to get the gunk off.

Fuses and relays check out, you said? I doubt the problem is in your instrument cluster. it might be a bad wire instead. Tracing that out is relatively easy if you have the wiring diagrams for the 940. Otherwise, I don't think I have the experience to help. :/

[98T5]

so you had someone step on the brake for you and verify that all the brake lights are coming on?

when you say that "it only comes on when you are coming to a stop", do you mean that it only comes on when you push on the brake pedal?

Yes, that's exactly what I'm saying. and yes, I used the Pep Boys storefront window to check all the back light bulbs.

[98T5]

I had this issue before with my 940 GL. You've done everything I have, save for two things.

1) Remove the wiring harness from the bulb bracket by disconnecting the wiring at the bracket. If it's badly seated, vibration and other movement in the body can make the connection work itself loose. Reseat it and test it again. I've seen brackets work loose over time, most annoyingly when I went in for inspection.

Wiring from the bulb bracket? can you explain what you mean? are you talking about the fuse box itself that's under the radio?

No dice?

2) Check for corrosion products on the terminals. Grey and dusty is okay, not preferable, but okay. Green or red terminals indicates moderate to heavy corrosion, which should be cleaned to restore proper functionality. A very fine piece of sandpaper (1500 grit or higher) can work, but I prefer to use Deoxit and a swab to get the gunk off.

Fuses and relays check out, you said? I doubt the problem is in your instrument cluster. it might be a bad wire instead. Tracing that out is relatively easy if you have the wiring diagrams for the 940. Otherwise, I don't think I have the experience to help. :/

I changed out the battery for a new when I bought the car and added corrosion inhibitor grease on the terminals and battery cables after I cleaned them off real good.

[98T5]

question for all:

How can I tell if the bulb failure warning relay is bad? that big circle relay in the fusebox in the back?

[98T5]

It seems to be a continuity issue. I ruled out the brake light switch because it works fine, changed the flasher relay because one of the terminals was blue looking and hot maybe burned. changed the relay and the blinkers work fine inside the car but now the bulb indicator blinks along when I click "right" but it doesn't do that when I click "left" ...and outside the car the front lights are in perfect working order, blinkers, beams, etc.. but the backup light on the left comes on but the right one doesn't come on, and when I turn, the right blinker does not come on but the bottom right brake light is the one that does the blinking and the left side is perfect with the blinker, brake light, backup light everything working just fine.

I read somewhere that the bulb failure relay which keeps the currents going even to both sides of the car is what causes this to happen. Can somebody confirm this?
Bulb Failure Relay pic here....
http://s3.amazonaws.com/fcp-product-pho ... 1295293713

[JohannReinhard]

My mistake, I should have been more clear. I suspect the problem lies in the wiring connecting the tail light bulb holder (the so-called 'bracket' I was referring to) rather than in the switches and relays. From what I can gather, the relays and fuses are fine, and doing their job as intended.

So, check to make sure that the electrical connections back there are in good shape. Unscrew the grey dust shield from the inside of the trunk so you can access the bulb holder. Squeeze either side of the bulb holder to remove it, and remove each bulb. Check the sockets for dust, dirt, corrosion, etc. These lamps have been known to fill with water and dust/dirt through split seams and cracks. If this has happened in the past, or even recently, it may have corroded the connections. If those are fine, look at the white molex connector on the bulb holder that provides power to the bulb holder. Disconnect it and inspect it for damage. Are the connections inside corroded? If so, clean them out, reassemble it and test it for functionality.

Perhaps the bulb failure warning relay is indeed bad. If so, it would be a new occurrence for me. I haven't heard of many of these relays failing. If you need a new one, shop around at the sponsors here for the best price. Alternatively, if you're feeling froggy you may try and repair it yourself provided you're comfortable with reflowing solder.

One last suggestion would be to check all the grounding points on the car's chassis and make sure they're clean and functioning properly. Improper grounds and corroded grounding points can do weird things to the 940's electrical system.

[98T5]

I'll check all that stuff tonight when I get off work. As of right now, the brake lights and blinkers work fine but the bulb indicator is blinking right along with every turn. so weird

[98T5]

update:

Now the bulb indicator comes on whenever...turn, stop, intermittent, etc...so it's defiinitely a grounding issue. I just hope I can pass inspection coming in June, gotta hunt that thing down before then.