I just want to give thanks in advance as my Q70 issues continue. So presumably a bad washer fluid sensor is causing the warning light to come on. After replacing the radio last week, my mechanic said he could remove the wires from the reservoir. He did that, and light still comes on. This is an electronic sensor built into the reservoir (have to replace whole thing). Does one have to connect the wires to complete the circuit in this case? I heard with previous models float valve removing the wires worked, but clearly doesn’t work here. Thanks for help.

I was having my light on constantly. All I did was pull the plug for the sensor itself at the bottom of the reservoir, blew compressed air into both ends of the plug, and checked that the plug was fully seated. It's fixed it so far, and maybe it will work for you.

Bonkle wrote: ↑

Fri Feb 03, 2023 7:47 pm

I was having my light on constantly. All I did was pull the plug for the sensor itself at the bottom of the reservoir, blew compressed air into both ends of the plug, and checked that the plug was fully seated. It's fixed it so far, and maybe it will work for you.

That’s interesting. Probably an uncommon cause of problems. Haven’t checked that. I was under the impression the problem was due to the metallic contacts having issues. And many cases of Rain X and certain fluids not working and causing conduction issues. How long has that worked for you. Last week I had the battery off for another reason and the light went away for several days for the first time since the summer. But then came back like usual.

haleakalag wrote: ↑

Fri Feb 03, 2023 8:02 pm

That’s interesting. Probably an uncommon cause of problems. Haven’t checked that. I was under the impression the problem was due to the metallic contacts having issues. And many cases of Rain X and certain fluids not working and causing conduction issues. How long has that worked for you. Last week I had the battery off for another reason and the light went away for several days for the first time since the summer. But then came back like usual.

I had the light come on and off, but it was on longer than it was off. Because it did have moments where it was off, I figured that there had to be some electrical contact that was dirty/loose. When I was doing my oil change, I figured I might as well check the sensor plug while I had the car in the air. Lo and behold, it really was dirty contacts. It's been about 2 weeks since, and before I cleaned it, the light would come on every day and would only turn off if I was lucky. I would suggest using dielectric grease to protect the contacts, too.

Bonkle wrote: ↑

Fri Feb 03, 2023 8:07 pm

haleakalag wrote: ↑

Fri Feb 03, 2023 8:02 pm

That’s interesting. Probably an uncommon cause of problems. Haven’t checked that. I was under the impression the problem was due to the metallic contacts having issues. And many cases of Rain X and certain fluids not working and causing conduction issues. How long has that worked for you. Last week I had the battery off for another reason and the light went away for several days for the first time since the summer. But then came back like usual.

I had the light come on and off, but it was on longer than it was off. Because it did have moments where it was off, I figured that there had to be some electrical contact that was dirty/loose. When I was doing my oil change, I figured I might as well check the sensor plug while I had the car in the air. Lo and behold, it really was dirty contacts. It's been about 2 weeks since, and before I cleaned it, the light would come on every day and would only turn off if I was lucky. I would suggest using dielectric grease to protect the contacts, too.

Very interesting. We’ll check that out. Still need to figure out if wires can be safely connected to turn off light if needed, since pulling them out didn’t work.

Ok, so we have a wire bypassing the sensor, and light still comes on. Other possibilities? If a short, any ideas where most likely? Or are we doing something wrong.

The light should have turned off as soon as you disconnected the sensor, it's a grounding switch and the Black/White wire goes straight to ground at E46 in the right rear of the engine box. Shorting the wires together should turn the lamp on, not off. If it's lit even when disconnected, either the Gray wire at the switch has a ground short someplace between the switch and the cluster, or you have a bad cluster.

If it is a ground short, the two most likely culprits are fatigued/chafed wires right at the switch or a water leak into the driver's kick panel causing shorts in the big SMJ connector (M6:E106) which joins the Main and Engine Room harnesses.

VStar- HIGHLY APPRECIATED. Calling my mechanic now.

VStar650CL wrote: ↑

Mon Feb 06, 2023 2:18 pm

The light should have turned off as soon as you disconnected the sensor, it's a grounding switch and the Black/White wire goes straight to ground at E46 in the right rear of the engine box. Shorting the wires together should turn the lamp on, not off. If it's lit even when disconnected, either the Gray wire at the switch has a ground short someplace between the switch and the cluster, or you have a bad cluster.

VSTar- So to confirm- this applies to the electronic sensor (not float sensor) that’s built into the Q70 Reservoir, not float sensor that was in previous models? For some reason he thinks the contacts need to be connected to make the circuit (light off) and might even be a capacitance range needed across it???

The '17 SM still showed a float sensor, not electronic, and it still showed a 2-wire ground circuit. In any case, either open or shorted should have put the lamp out, so if neither one does it, it has to be an issue upstream no matter what type of sensor is used.

I just double-checked the FSM and they don't show anything special about the switch. It isn't electronic, just a self-contained float with normal on-off action.