Windscreen Wiper Fuse Blowing - tracing intermittent fault?

[CherryTreeFW]

Hello

I have a Westfield SE FW on a 21 plate powered by a Zetec Blacktop 2ltr on Omex Throttlebodies.

The slight fly in my ointment is an intermittent fault which keeps blowing the Wiper fuse (10A).

I've checked the power load across the fuse which runs pretty consistently at 2-5A (lowspeed) and 3-6A (high speed). Voltage is consistent too at just over 12v with the engine not running and just on 14v when the engine is running.

Nothing changes from that when I switch on all the lights and fan or when I switch the wiper motor direct to fast speed.

I haven't accessed the Wiper Motor to check it with my tester, but it appears to be running freely - there's no stiffness or apparent resistance in the operation of the wiper heads.

My next plan is to start checking downstream from the fusebox but I'm struggling a bit with identifying the relevant cabling in the loom and in working out a way of identfying and isolating a short when there are sections of the loom which are hidden.

Has anyone got any tips/ suggestions etc?

Thanks in anticipation.

Regards

DAVID

[blue]

If your running the MINI wiper motor replace the park switch located on the motor -when it becomes faulty it sometimes causes a straight to earth popping the fuse. 

[nelmo]

OK, if sensible suggestions don't work, I'll be first to give you the Heath Robinson solution - a 20A fuse 

Bad, I know but having had other electrical issues that took me months to fix, life is just too short... 

Obviously, if that blows as well, then you're in deep doo-doo... 

Edited October 5, 2021 by nelmo

[CherryTreeFW]

13 hours ago, blue said:

If your running the MINI wiper motor replace the park switch located on the motor -when it becomes faulty it sometimes causes a straight to earth popping the fuse. 

I'll check - this was a full westfield kit build, so it will have the motor which comes as standard with the kit bundle. I'll check and if it's the Mini I'll try that....Cheers

[CherryTreeFW]

11 hours ago, nelmo said:

OK, if sensible suggestions don't work, I'll be first to give you the Heath Robinson solution - a 20A fuse 

Bad, I know but having had other electrical issues that took me months to fix, life is just too short... 

Obviously, if that blows as well, then you're in deep doo-doo... 

Thanks! I'm currently on a temporary fix along those lines - I'm going to spray washer fluid and then operate the motor for a good while to bed it in thoroughly (the car is on a 21 plate and so the Wiper motor has probabvly had little to no use, the vehicle having only got its IVA approval and been registered this June).

In the meantime I'm running it on a 15A fuse (some people suggest no, but others suggest it's ok while the motor gets run in and smooths out the stickiness).

I don't tjhink I'd be brave enough to put a 20A fuse in just at the moment........

Cheers.....

[Sparepart]

Googling what fuse ratings are used on a "classic" mini, gives this link:-

https://www.theminiforum.co.uk/forums/topic/251403-fuses-by-location-circuits-covered-data/

You will note that on later models the WW fuse is 15 amps, what you are now using.

 

[CherryTreeFW]

1 hour ago, Sparepart said:

Googling what fuse ratings are used on a "classic" mini, gives this link:-

https://www.theminiforum.co.uk/forums/topic/251403-fuses-by-location-circuits-covered-data/

You will note that on later models the WW fuse is 15 amps, what you are now using.

 

That’s really useful thanks - while I’m sorting a permanent fix I’m running a 15A fuse which doesn’t seem from the data you’ve found to be too much of a risk… Cheers,

[IanS]

Fuse is to protect the wireing not the load.

Most kit looms use 2 guages of wire, high current (from alternator etc) and normal which will be OK at 20A.

[CherryTreeFW]

On 10/7/2021 at 11:54 AM, IanS said:

Fuse is to protect the wireing not the load.

Most kit looms use 2 guages of wire, high current (from alternator etc) and normal which will be OK at 20A.

Ian good point - good to be reminded, thanks. D

[sylvia.fry2]

If you're still having trouble locating the exact point at which the fuse blows ----- wire a high wattage filament lamp, solder both filaments of a headlamp bulb together will give 100+ watts ( not wimpy LED ) in place of the fuse --- the motor will still run, but slowly & lamp ( bulb ) will glow at full brilliance once the fault/dead short is reached & motor should stop at that point.

[CherryTreeFW]

14 hours ago, sylvia.fry2 said:

If you're still having trouble locating the exact point at which the fuse blows ----- wire a high wattage filament lamp, solder both filaments of a headlamp bulb together will give 100+ watts ( not wimpy LED ) in place of the fuse --- the motor will still run, but slowly & lamp ( bulb ) will glow at full brilliance once the fault/dead short is reached & motor should stop at that point.

Sylvia - good idea, thanks: a good excuse to get my cobwebby soldering iron out!

[CherryTreeFW]

Just by way of update - taking on board a host of tips (thanks again) I applied Rain Screen, ran the wipers for a good while at both speeds to get them well bedded in and inserted a 15A fuse. All is well since then so, hopefully, problem solved.... 

[nelmo]

Do you find that RainScreen works? I tried RainX (similar stuff, I guess) but it relies on causing the water to bead and then the airflow to blow if off the screen. Weird thing is, though, that despite my flat screen seeming to be facing directly into any windflow, I get absolutely ZERO wind actually on the screen itself, so the water never gets blown off there.

The weird science of aerodynamics, I guess... 

[CherryTreeFW]

On 10/14/2021 at 4:37 PM, nelmo said:

Do you find that RainScreen works? I tried RainX (similar stuff, I guess) but it relies on causing the water to bead and then the airflow to blow if off the screen. Weird thing is, though, that despite my flat screen seeming to be facing directly into any windflow, I get absolutely ZERO wind actually on the screen itself, so the water never gets blown off there.

The weird science of aerodynamics, I guess... 

@nelmo - sorry, my mistake, it WAS RainX, I got the names mixed up. Difficult to tell how it works on mine as the wipers are so poor! 

I was really just using it as a lubricant to give the motor some bedding in time as an attempt to solve the fuse problem - seems to have worked! 
 

Now I have to solve the Wiper Problem!