2007 XC90 left rear turn signal works intermittently Topic is solved

bethanyXC90 · Post by **bethanyXC90** » 27 Jul 2018, 12:05

Hello all,
I joined this site hoping one of you experts can help me! I searched for "xc90 turn signal" in hopes that someone had seen/solved this issue but couldn't find anything.

When I signal to turn left, my dashboard message center says BULB FAILURE and the driver's side front turn signals & dash indicator arrow are both blinking fast. Bad bulb, right? So I replaced the bulb and it still didn't fix the issue. Replaced it with another bulb, same issue. Put the suspected bad bulb in the passenger side; works fine. Put the working bulb from the passenger side in the driver's side; doesn't work. So I assume something's wrong with the socket/wires/fuse/switch on the driver's side since the same bulb works fine in the passenger socket.

Checked the fuses for both sides. They look fine, but I replaced them anyway; still doesn't work.
Wires look fine (but I don't really know what I'm looking at there, honestly).
Tested hazards; left rear bulb doesn't light up with turn signal stalk or hazard so it's something with that specific area.

I flicked the turn signal on and measured the voltage across the dead bulb socket and it's 0, but I have a feeling I'm not taking everything into account. I did the same thing on the working side and the voltage varied as expected (blink blink blink).
What's wrong? Could it be the relay? Wouldn't front, rear and mirror signals all be out if it was the relay?

The following question is a general question which will certainly show my ignorance, so forgive me as I am not a car expert. This question came up as I was trying to diagnose my original issue.

I have attached the cargo compartment fuse box diagram.
#29 is labeled "Trailer lighting, left: position lamps, direction indicator"
#30 is labeled "Trailer lighting, right: brake lamp, rear fog lamp, direction indicator"
Both are 25A fuses. I took them both out and the turn signals still functioned! Can someone explain this? I thought if I took the fuses out, the circuits would be open and no current could flow???

Post by **ggleavitt** » 27 Jul 2018, 12:36

: XC90 Turn Signal_2007_Wiring.JPG (70.48 KiB) Viewed 9104 times

Try fuse #2, see what that does.

Wire color code for left turn signal is Green for 12V, Black for ground. Wire color for right turn signal is Green/White Stripe for 12V, Black for ground.

If fronts signals are working, then your switch is working.

EDIT- Had wrong issue identified, re-posting with turn signal

bethanyXC90 · Post by **bethanyXC90** » 27 Jul 2018, 12:41

Thank you for your reply. When you say "stop lights" does that also apply to turn signals? I am going into my garage to check #2 in the cargo fuse box but wanted to make sure that's what you meant.

Post by **ggleavitt** » 27 Jul 2018, 12:48

See above, corrected. Fuse 2 is likely to be fine. Maybe walk through the connections with the car off and a multimeter (ohmmeter) to check left versus right for a short or open at the plug. Measure the pin to pin resistance and pin to ground.

bethanyXC90 · Post by **bethanyXC90** » 27 Jul 2018, 13:02

Ok, I went outside, got in the car, turned the car on, then flicked the stalk down to test the left turn signal. It was blinking fast as expected. Then I got out, leaving the driver door open, pulled cargo fuse 2 out, no change (is this normal? Maybe I don't know how fuses work).

But then! I got back in and closed the driver door slightly, and it all started working fine. All three left turn signals blinking at the same rate. Opened the door slightly, rear one quit and the others started the fast blink. Closed the door a bit, all fine. Opened the door a millimeter, fast blink. Closed it a millimeter, all fine. So could it be a connection inside the driver door? This is getting weirder and weirder.

Post by **ggleavitt** » 27 Jul 2018, 13:29

It's actually a good thing, now you know where to look. Driver side door has a known issue whereby the wires can get worn out and fray. That it's a driver side issue with driver side door position making a difference is perhaps indicative of a worn wire or partially mechanically compromised conductor in the path between door and car body.

Couple posts on this- https://volvoforums.com/forum/volvo-xc9 ... lem-81755/, viewtopic.php?f=10&t=66793, https://forums.swedespeed.com/showthrea ... om-harness

I'll take a look at the wiring diagram, see if there's something obvious to validate but start looking right where the cables go into the door (pop the rubber cover at the door). Better yet- open the door, pop the rubber cover, and wiggle the wires while you try the turn signal. If it works that way, you know where your problem lies.

Post by **ggleavitt** » 27 Jul 2018, 13:44

Look specifically at the green with white stripe conductor in the connector right at the door itself (pin 7 I think), should be 2 wires of the same color in a single crimp. Turn signal on left mirror working properly ? If yes, I would guess that one of those terminations- likely the conductor which heads back to the REM (A:21)- is compromised. Last link-first photo shows what it should look like in the door. Here's another link with a "like" issue- https://forums.swedespeed.com/showthrea ... gnal-is-on

Edit- 7/27/18- add info, link, remove solid green wire

bethanyXC90 · Post by **bethanyXC90** » 27 Jul 2018, 14:15

Thank you, I will check those links and try to do a bit more debugging. I will follow up!

bethanyXC90 · Post by **bethanyXC90** » 28 Jul 2018, 10:15

BINGO. One of the green wires is broken. I didn't even have to turn the signal on to figure it out ... as soon as I popped the rubber cover off and pulled out the wire harness, it was obvious that one of the green wires was broken in such a way that the ends could still connect if they were in a certain position. The black wire is frayed as well, but still connected enough to conduct (at least it appears so). Luckily there seem to be plenty of links showing how to fix this. I will follow up once I do the repair and let you know if it works. Fingers crossed!

Post by **ggleavitt** » 28 Jul 2018, 21:02

Was thinking about this while you checked, the green/white wire is easy enough to resolve since it's the same conductor. It's the ground that's going to be a little more problematic. You could dump a bunch of solder in the area and hope for the best, but that spot is always going to be a flex point so you'll probably just buy some time (small tie wraps around the whole bundle in that area might make it flex less). For sure read up on what others have done and if there's the slightest chance the repair involves the metal inserts for a proper re-crimp, please post part numbers and tools used. Gotta be a pin repair kit for these types of connectors being sold somewhere in the world...

Push comes to shove you could pop the door panel, pull both pin and socket out from both sides of the connector and use a small bit to drill out the black wire path in the connector body itself. Run and solder with heat-shrink an appropriate gauge stranded wire (14ga maybe?) tie line, lock it down with tie wraps on both sides of the door, plug both sides of the connector hole with some silicone and close everything up. You would then have a permanent connection that's itself a flex point.

Great to see another photo, I'll have a look at both my cars and put it on the list of things to check from time to time. Apologies for the brake lamp mixup, was not reading thoroughly before responding.

Good luck with your repair !