I've been reading that this is a common issue, but I've seen help for 240, 960, but not any for s70 so far. I don't have a multimeter so I can't check the circuit.

Is anyone familiar with the 1999 s70 to understand how to jumper this wire correctly to test the panel?

1 Yellow/Purple stripe
2 Black
3 White
4 Pink
5 White/Black stripe

Any help would be appreciated.

Here are the pictures of the rheostat I pulled out.

 

Jumpering wires is never a good idea. You should get a volt/ohm meter and test for power. Jumpering will usually just get you a shorted circuit and a blown fuse.

You will get 12+ volts for power wires. If you tgry to ohm out a wire with power you will likely blow the fuse in the ohm meter, so always check for power first.

 

Does any of the interior dash lights work? Radio? Climate control? Etc.

 

The warning lights work. The radio display works. But nothing else is lit with the head lights on

 

took it to a mechanic today that had a spare rheostat and light switch. he confirmed that both of those worked in another volvo. so it's some short in the wiring. What's the best way to troubleshoot now? that mechanic was stumped

 

If there is a short it will show up as a blown fuse, no matter how many amps the fuse is. You did not say if there are any blown fuses.

Randomly replacing parts will only get expensive.

An electrical issue is one of those patience things. If you have a wiring diagram its much easier. If you don't, you have to trace wiring. You need a VO meter.

If you can't get a wiring diagram you can trace wiring. Since you don;t know where the power originates from you hvae to approach it from the other end. In this case, you would take the cluster out of the vehicle and measure voltage at the cluster.

Shorting a circuit is not a way to tell if there is power. If there is power it will for certain blow a fuse and may damage something else, including the wiring. VOM's are cheap enough and you only need to see that there is 12 V at a circuit. You ground 1 lead to the car itself. Don't measure voltage between circuits unless you absolutely know something is a ground. Do yourself a favor and ground to the somethign on the chassis - all grounds lead to that.

Good luck hunting!

 

thanks Kwatt for the tips. The instrumentation panel doesn't blow any fuses and the fuses all look good. I'll get a volt meter and check it out. the one I have now is a sperry analog. This model. sufice it to say, i'm totally lost on how to use this tool effectively. I've watched some videos on youtube on how to read shorts and continuity.

http://www.kellaninc.com/ProductImag...ncIMG_5123.jpg

Is this a good enough tool or the wrong one?

The wiring diagram I have is for the instrument cluster. It's kinda helpful, but from what I can tell...it's not matching up the wire colors completely. It's a mitchell version.

 

That kind of VOM is good for lots of stuff. If you are just wanting a cheap VOM fo rthis job you can likely pick one up at a walmart or parts place for cheap too. I have one similar to the one in the link and I use it for just about everythign electrical. You can also measure for current leaks with it but that is another story

 

i bought one of these after watching a video on how to troubleshoot to find
Performance Tool Deluxe 12 V Circuit Testers W2975C - Free Shipping on Orders Over $99 at PowerSports Place

https://www.google.com/url?sa=t&rct=...FBLnZCUube-_aA

I took the center console out and looked at the gear shift light bulb to see if that was causing it. it looks burned out, so I'll get a new bulb. Can a burnt bulb cause a short?


but i didn't come up with anything. i'm thinking I need a mechanic to trace the short circuit down.

 

1st, take a serious look at the led bulbs. I don't know what bulb it uses but i had 2 cars within a few weeks that the shifter light went out. I bought the LED typoe and they are outstanding. They happend to be something like $3 each plus shipping. the regular bulbs are about that.

2nd, yes, a bulb can create a short. However, you stated that you do not have a blown fuse. Unless the circuit has a self resetting circuit braker, any fuse would pop if there was a short. You could have a OPEN circuit which could be anythuign from a broken connector, cut wire and the list goes on.

If you feel like fishing some more, trace the wiring for the shift console light. With the console out its fairly easy to trace back. Use the VOM to test for 12 V. Secure the ground (black) kead to the chassis - any good body ground.

With the bulb assembly out of its socket....

Turn on the headlights (not auto) and measure the voltage at each terminal for the bulb. I've used a paperclip, clipped to the red lead, in the past. just be careful not to short th wiring as this will most certainly blow a fuse if the circuit is indeed good.

If you have voltage, the bulb is bad. if not, it may or may not be back Also, you can test a bulb using the battery. Ground one lead of the bulb and apply 12V to the other.

Keep going backwards until you either get to a fuse panel or a relay. if you get to a relay, check to make sure it is good. Usually if you pull a relay there is a switching diagram imprented on it somewhere. Tells you which 2 posts are for the coil and which posts are C, NO or NC (Common, normally open or normally closed). If you think the relay is good, the test the C and NO sockets. Usually the 12V from the fuse is the C socket. the NO soket is the side that goes to out to the bulbs. When the relay energizes, the NO to C circuit closes and you get power on the NO lead.

Like I said, this is a tedious exercise and requires patience and a little understanding of electrical circuits.

 

So I changed my heater core on Sat. with no issues and kept the panels off until today to double check if there are any leaks.Put it all back together today and was about to start troubleshooting the electrical issues, when I thought "i'm gonna see if the lights work just for fun." and sure enough....something knocked the wires okay and the dashboard, a/c control and radio lights came on. The radio lights had the lower right side less lit, so i wonder if there is a bulb out and the gear shift is still out so i bet that bulb is out. I'll look into swapping out new bulbs soon. thanks for all the help. We'll see how long this lasts.

 

other lights work on normally