1996 960 gauge cluster issues

[96_960]

Recently purchased a 1996 960 and I'm trying to diagnose and track down some issues.

• Speedometer non-operational
  Odometer non-operational
  Gas gauge stuck at just above 1/2 tank
  Cruise control non-operational

The car also has an issue with the ignition tumbler. After starting the car, the key has to be manually turned back slightly in order for the electronics to work. Otherwise, the radio, lights, dash lights, etc don't turn on. Turn the key back a touch and everything else works properly. Not sure if this is related to the other items or not.

I pulled the plug to the sending unit and the gas gauge dropped to empty and the low fuel light turned on. That tells me the gauge is getting an electrical signal from the sender, but the sender isn't responding to the fuel level in the tank.

I checked all of the fuses in the cabin fuse block adjacent to the driver's door, and all the fuses in the fuse block in the engine bay. They all checked out. I also did a bunch of research on the ABS units in the 850's, but one of the module rebuilders told me that the ABS units on the 960's are totally different, rarely fail, and are not reparable.

Also hooked up an OBDII reader and connected to my phone via Torq. Device is sending speed and trip data (along with a bunch of other data), and there are no codes in memory.

Any suggestions for further diagnostics are greatly appreciated. I'm a reasonably handy DIY mechanic, but need some direction on a car that I'm not yet familiar with.

[lummert]

First off, I'd diagnose the ignition switch. You'll find the ignition switch hidden directly opposite the lock cylinder, accessable by removing the steering column covers. What you're describing could be a bad ignition switch. The speedometer problem may be a speed sensor issue. Speed sensor is located on the rear differential cover. Cruise control problem may be related to speedometer issue. Fuel gauge problem may be caused by stuck sending unit.

[96_960]

Thanks for the reply. I suspected the ignition switch as well. I'll dig into that.

Question: if the speed sensor on the rear diff is faulty, will the OBDII module still receive speed data?

[96_960]

Update for others tackling this in the future:

Decided to start with the gas gauge. Opened up the jack storage cubby behind the driver's side rear wheel well to access the plug for the sending unit. As I mentioned in the original post, when I pulled the plug, the gauge dropped to zero. I further diagnosed by jumping the sending unit leads (the two center leads) with a paperclip, and the gauge very slowly climbed up to full. This gave me the confidence that the problem was the sending unit.

Removed the interior panels to access the access panel for the sending unit. Pulling the hoses was pretty easy. Removing the "mayo jar lid" took some effort. Ultimately, I used a cat's claw and hammer and carefully tapped it open a little at a time. The plastic is fairly soft, but it eventually came free.

Getting the sending unit free was... frustrating. Everything I read said it's a pita, but that it WILL come out. I finally resorted to spraying some WD-40 around the seal and using a pry bar to get it unseated. Surprisingly, I didn't damage the lid or seal. Once loose, I discovered that the large fill hose had another hose clamp hidden under the deck. Removing that made it possible to push the fill hose out of the way, and the sending unit came out pretty easily.

Then I followed the instructions in https://www.volvoclub.org.uk/faq/Electr ... Fluctuates to disassemble and repair the sending unit.

Putting everything back together was fairly straight forward.

I did most of this job at night, outside in the rain, in December. If I can do this, anyone can. I'm happy to share a few pictures if anyone is interested.

[96_960]

Replaced the ignition switch today. Super easy project thanks to the tutorials here. That fixed the loose key/ dash light issue. But still no speedo/odo.

Next up, check the speed sensor on the read diff.

[96_960]

Pulled the speed sensor off the rear diff today. Sprayed it with electronic cleaner and plugged it back in. Test drove the car, but still no speedo/odo. I know that cleaning it doesn't rule out the sensor as a possible problem, but wanted to give that a shot first.

I should mention, the ABS light is not lit. It lights in the key on position (before ignition), so the lamp is fine. Also, the vehicle has not thrown any codes, according to the OBDII reader via Torque.

Are there other diagnostics I should try before pulling the instrument cluster?

[durk80]

Just a thought. My cruise was non-operational on my 240. I checked underneath by the brake and clutch pedals and there were two switches on a plate. The plate was bent, so i straightened it out so the switch would trip when the brake and/or clutch is depressed. This made the cruise control operational again.

Also, if you just purchased the car, perhaps someone did some tinkering before and forgot to plug in all of the connectors on the instrument cluster. For the odometer, you'll probably have to buy a new gear to make it operational as mine was crumbly. This could be the same for the speedometer as well. I have to do this for my 850 because it is binded and will not move. My terminals were also very corroded as well. Electronic cleaner and 120 sand paper cleaned it up. Best case scenario, the connectors aren't fully seated.

Just don't try to take out the plastic front to clean. I wound up cracking it because I thought it would slide out after a couple of beers...

[mydamnvolvo]

You could have a corroded ground wire, if the issue isn't solved. This happened to my BMW 525i and my Dodge Grand Caravan where the speedo and gas economy wouldn't work in the beemer and the speedo and rpm wouldn't work in the Dodge. This happened because of my battery which I had switched in the cars. I have one battery for my two cars (High theft in my area) and the Dodge is my winter car. The batt leaked acid on my wire.