Brake lights fuse keeps blowing ?
Discussion
Ok was told the other day had no brake lights (it did 2 weeks ago as passed MOT) so did the following ;
1) pulled wires to brake light switch linked them but no brake lights
2) pulled connector in passenger cubby cleaned and refitted no brake lights
3) checked fuse 18 (this is brake lights and wiper park “fuse was blown”
4) replace fuse blow straight away , disconnected cubby hole connector another blown fuse , disconnected the brake light switch “it blow again”
The fuse blows on ignition , don’t have to touch the brakes as soon as key in position 2 fuse blows with all the above disconnected so yes I have a short but wanted some advice as in , Is it a case of finding the short or have I missed something ? Being TVR wanted to check there was not something that could blow fuse like park switch connection ? Or relay I’m not aware of ?
Thanks
1) pulled wires to brake light switch linked them but no brake lights
2) pulled connector in passenger cubby cleaned and refitted no brake lights
3) checked fuse 18 (this is brake lights and wiper park “fuse was blown”
4) replace fuse blow straight away , disconnected cubby hole connector another blown fuse , disconnected the brake light switch “it blow again”
The fuse blows on ignition , don’t have to touch the brakes as soon as key in position 2 fuse blows with all the above disconnected so yes I have a short but wanted some advice as in , Is it a case of finding the short or have I missed something ? Being TVR wanted to check there was not something that could blow fuse like park switch connection ? Or relay I’m not aware of ?
Thanks
Do you have a multimeter?
If so then (with nothing switched on) pull fuse 18 then go to the brake pedal switch, unplug the wires and test if the green wire is connected to earth (gear knob or handbrake lever often offer a good earth. If you are not sure test one against the other first)
If there is continuity then you have a short somewhere.
As you say the other circuit is the wiper motor. So again go there and unplug. Test continuity of the green wire to earth.
Report back with your findings. If both have continuity (a short) then you have the challenge of finding it within the dash which will not be fun however there are more connectors that can be pulled to isolate the problem but we can get to that when we know more. Fortunately whilst the circuits share the same fuse they come out of the fusebox on different connectors.
Steve
If so then (with nothing switched on) pull fuse 18 then go to the brake pedal switch, unplug the wires and test if the green wire is connected to earth (gear knob or handbrake lever often offer a good earth. If you are not sure test one against the other first)
If there is continuity then you have a short somewhere.
As you say the other circuit is the wiper motor. So again go there and unplug. Test continuity of the green wire to earth.
Report back with your findings. If both have continuity (a short) then you have the challenge of finding it within the dash which will not be fun however there are more connectors that can be pulled to isolate the problem but we can get to that when we know more. Fortunately whilst the circuits share the same fuse they come out of the fusebox on different connectors.
Steve
Edited by Steve_D on Sunday 30th August 18:19
Thanks Mr D not got a multimeter never used one (holds head in shame) but.....I’ve got brake lights again , I’ve disconnected the plug to wiper motor which in effect is the park switch combo and fuse does not blow and I’ve brake lights back but now no wipers !
Fuse 18 is the park switch circuit, and another fuse says it’s wiper motor it’s self (two different fuses that say wipers ) 18 I’m think is park switch , so yes short in loom somewhere perhaps ? Or do you think it’s more likely the park switch shorting ? (I replaced park switch over a year ago and it did work for a while then stopped parking and if I’m honest not used the wipers until the MOT , lights were tested first then wipers and wash etc which at the time worked fine but have no idea if brake lights worked since the MOT (the connections in wiper switch and terminals do look good any tips on next steps ?
Thanks
Fuse 18 is the park switch circuit, and another fuse says it’s wiper motor it’s self (two different fuses that say wipers ) 18 I’m think is park switch , so yes short in loom somewhere perhaps ? Or do you think it’s more likely the park switch shorting ? (I replaced park switch over a year ago and it did work for a while then stopped parking and if I’m honest not used the wipers until the MOT , lights were tested first then wipers and wash etc which at the time worked fine but have no idea if brake lights worked since the MOT (the connections in wiper switch and terminals do look good any tips on next steps ?
Thanks
If you are not blowing the fuse with everything plugged in apart from the wiper then it is the wiper park switch.
You could leave the fuse out and check that the wipers work on slow and fast proving it is not the motor. You will not have park or intermittent as those require fuse 18.
Also so you are aware the wipers have 3 fuses..15, 17 & 18.
15 powers the delay module
17 does all speeds plus wash
18 does park (intermittent turns the motor on and park finishes the cycle)
Park switches are cheap and easy to fit.
Steve
You could leave the fuse out and check that the wipers work on slow and fast proving it is not the motor. You will not have park or intermittent as those require fuse 18.
Also so you are aware the wipers have 3 fuses..15, 17 & 18.
15 powers the delay module
17 does all speeds plus wash
18 does park (intermittent turns the motor on and park finishes the cycle)
Park switches are cheap and easy to fit.
Steve
Park switches last for many operations from new
If it's eating park switches the motor is very likely drawing too much current through the park switch
If the motor is drawing too much current it will be overheating and very likely damaged
A motor drawing too much current is caused by a tight rack and wheel-boxes or linkage
Pain of a job but the whole lot needs checking to be sure
If it's eating park switches the motor is very likely drawing too much current through the park switch
If the motor is drawing too much current it will be overheating and very likely damaged
A motor drawing too much current is caused by a tight rack and wheel-boxes or linkage
Pain of a job but the whole lot needs checking to be sure
TVRSJW said:
Yes PS thanks will open up and re-grease as doubt it’s ever been done as looks untouched from new !
If you are going to grease the rack then start by removing the wiper arms. Wrap masking tape around the spindle joining the ends together to form a flag pointing away from the spindle. At this time it does not matter which direction the flags are facing.Remove the wiper gearbox cover. Remove the circlip holding the drive cable onto the drive gear pin.
Remove the wiper motor/gearbox and put to one side.
You can now pull out the drive cable (and watch your flags going round and round).
Grease the drive cable over its whole length.
Now the important bit...Go to each of the spindles and do two things..turn it through 180 degrees but at the same time register how freely it moves.
These spindles (known as wheel boxes) wear at the point where the drive cable runs so turning them puts the drive cable on an unworn section.
You can now re-fit the drive cable.
We don't even want to think about the wheel boxes being stiff as removing and replacing them involves removing the dash and (i believe) cutting access holes through the GF below the lower edge of the windscreen. Report back if they are stiff as there may be ways around taking the dash out.
Steve
Adding to the very good Steve_D post above
If you get as far as pulling the rack out, it may well be worthwhile fitting a new one as they do wear and also go stiff
If the wheel-boxes are tight, try pushing rubber hoses over the spindles, clamp them tight if need be and spray/pour plenty of penetrating oil into the hoses so that it might slowly run down the spindle shafts, tie rags around the bottom of the spindles where they exit the bodywork panel so as to catch any oil
About turning the spindles 180 degrees, it works a treat but there is a catch. Make sure that they haven't already been turned in the past
If you get as far as pulling the rack out, it may well be worthwhile fitting a new one as they do wear and also go stiff
If the wheel-boxes are tight, try pushing rubber hoses over the spindles, clamp them tight if need be and spray/pour plenty of penetrating oil into the hoses so that it might slowly run down the spindle shafts, tie rags around the bottom of the spindles where they exit the bodywork panel so as to catch any oil
About turning the spindles 180 degrees, it works a treat but there is a catch. Make sure that they haven't already been turned in the past
Update > my new park switch arrived pulled fuse 18 so it didn’t blow set wipers at 12oclock removed wiper connector and park switch did my best to clean everything and ensure good connections used wurth contact spray fitted new park switch replaced fuse and fingers crossed and so far it’s doesn’t blow ! Result !
I now have wipers that park , and brake lights !
This park switch was fitted new about 12 months ago and had gave up already !
Many thanks Steve D for pointing me in right direction I can now drive in the rain use my wipers and tell everyone I’m braking !!
I now have wipers that park , and brake lights !
This park switch was fitted new about 12 months ago and had gave up already !
Many thanks Steve D for pointing me in right direction I can now drive in the rain use my wipers and tell everyone I’m braking !!
TVRSJW said:
............This park switch was fitted new about 12 months ago and had gave up already ! ...........
A sad fact you meet all to often.How many times on here do we hear of people retrieving parts from under the bench when the new part has failed
Dizzy caps
Rotor arms
Sparkplug extenders
Fuel hose (don't use the old ones buy a decent brand)
Rubber parts like rack gaiters and TRE boots.
Steve
Thanks Adrian , the one I ordered said Genuine Lucas , but also understand there old Lucas and new Lucas In terms of quality , well they park and all three settings work , else it would be a trip Cov again Adrian !!! Btw my steering Wheel is still looking brand new thanks !!
It’s hard to know what to trust these days even fake NGK plugs out there !
Yes I have spare cap and rotor and ordered them from the Distributor doctor as heard new rotor arms failing in months causing poor running ! Mine are ok so kept them as spares in the boot !
Given everything a good dose of wurth electrical contact spray !!
It’s hard to know what to trust these days even fake NGK plugs out there !
Yes I have spare cap and rotor and ordered them from the Distributor doctor as heard new rotor arms failing in months causing poor running ! Mine are ok so kept them as spares in the boot !
Given everything a good dose of wurth electrical contact spray !!
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