Help Please Heated Washer Jets Voltage


Registered User
Evening all,

Just a quick question. During the recent cold weather we've had, my windscreen washer jets don't want to play. They're fine when its gets a little warmer though. Because of this, I'm not sure my heated washer jets are working.

The rear always works, so its not the motor freezing up or the fluid in the hoses. Although I have just ordered some -70 concentrated fluid anyway.

So, my question is, what should the voltage across the heated washer connector be? I went to check them earlier today, but the weather wasn't cold enough for the heated jets to activate. (at least the frost symbol was not on the DIS - around 7 degrees today)

Hopefully the weather will be cold enough to check them again tomorrow.

Thanks in advance.


Registered User
Guessing is not my normal way to operate, but I'm sure that they are just 12V , I'm not sure if the rear one is ever heated.

You are sure that that car has heated windscreen washer jets, ie you have have seen the wiring heading up to the jets along with the fluid hose.


Registered User

thanks for the reply. Yeah, I guessed it would just be a 12v system, but wasn’t sure it wouldn’t be some spurious low voltage thing.

Yeah, the car definitely has heated washers, I replaced the washers a few months ago for the fan type. I’ve already tried to test the wiring, but it still wasn’t cold enough for them to activate.
I know, the rear isn’t heated, I just find it strange that the front freezes up, but the rear doesn’t, yet the front should be heated.

I’ll have to wait for the temperature to drop again to be able to test them. Or trick the OAT into thinking it’s colder than it is.

In the meantime, I’ve added a bottle of concentrated washer fluid which works down to -70•. Hopefully that’ll help.

thanks again mate.


Registered User
I and some others, seemed to assume that these washer jet heaters were powered on at all times the engine was running, which is fair enough as the current draw would be very low, but probably does not avoid the worst case situation which will be when the temperature falls quite a bit and the washers freeze up when the engine is not running - and so as they are very small wattage heaters, take too long to defrost the jets and so you will get left without any washer fluid coming out after a cold start.
I can see the logic of using the ambient air temperature reading to initiate these heaters though, as it is already being used to protect the chiller operation.
I used to have a 2000 VW Passat B5, so really just an Audi B5 with poorer clothes, I believe that the Audi had thermostats in the mirror heaters or some other way to control the operation of the mirror heaters, I had just moved from having a 1991 VX Cav GSI 4X4 and it had heated mirrors - but they could only be selected if the rear screen heater was being used, which was on a timer as many were. The 2000 VW Passat 4Motion did not have a timer for the rear screen heater, and worse than that, if you left the mirror heaters switched on, even in coolish weather, they burned out - I discovered this design weakness after reading posts in the USA Passat owners forum, and yes both my mirror heaters had burned out but as when doing that the backing fabric gets turned into a black mess, ie carbon and still conducting, any vehicle scans missed that the heaters were now u/s - but when changing the mirror glasses, heater faults were logged for both mirrors.

Having said all that, my wife's last two VW Polos have had winter pack and the washers have never ever ended up freezing, though that car, and mine tend to be garaged all year round - but ended up parked outside when away from home.

Edit:- retro fitting heated washer jets seem to have become a "must do" in some other VW marque motoring forums, and so far no one has provided any posters the answer to the question " where does the supply come from for these heaters?" - though like my old VW Passat, I'd think that the answer will vary marque to marque - maybe I could educate myself by looking up some wiring schedules!