conFUSEius

[McMuttley]

I need to look at my electrickery over the w/e.

 

On the way up to Silverstone the wife (following in the support non-TRuck) pointed out that my brake lights (both) were not working.

 

On the way back I noticed that the only dash light working was the new ammeter - which shone brightly - every thing else under the spell of the lord of darkness.

 

Otherwise front and rear lamps and indicators were fine and no other obvious electrical 'outs'.

 

Before I start poking around and making things worse, is there a common fuse for dash and brake lamps that might explain this coincidence/chain reaction?

 

Otherwise I will check whether:

(i) whatever punted my boot badge onto the M1 also dislodged the brake light wiring (does the main feed come down the driver's side ?)

(ii) whether the sparky noises that brought me to a halt on the way to Gaydon has done worse behind the dash.

 

 

Cheers

 

 

"Real knowledge is to know the extent of one's ignorance"

Confusedius (founding member of Chinese TR Register and consequential philosopher)

 

 

 

 

 

 

[RogerH]

Hi Austin,

have you got a decent wiring diagram

http://www.advanceautowire.com/tr24a.pdf

 

Roger

[RobH]

If your wiring is standard Austin then no its not related - the indicators and brake lights both run from the 'A3-A4' fuse. The headlights and panel lights are on another circuit and are not fused at all , (except on US cars apparently).

 

If both the brake lights are out but the other half of the bulb works OK on sidelamps, it could be a problem wiith the feed from the hydraulic brakelight switch or with the switch itself.

 

Best to start by looking at the bulbs and bulb holders, make sure the bulbs are Ok - the solder pip can flatten after many years and cease to contact - and make sure they seat properly in the holder and that the holders are making a good earth connection - the panel lamp holders are a poor push-in fit .

Edited August 5, 2016 by RobH

[Dave Larnder]

Austin

 

Were the rear indicators working all the time? If not more than likely it is an earth lead problem which I hope you have installed separately and not relying on the contact of the whole of the units to the body.

Of course, it could not be related to the fact that you were OUT OF YORKSHIRE, and the southern gremlins got you.

 

Dave

 

[BlueTR3A-5EKT]

If you short out join the two wires connected to the hydraulic brake light switch does the pair of brake lights work? If so it is a dud switch. (Ignition needs to be on and assistant at rear to observe)

 

Our experience is that modern replacement hydraulic brake light switches are junk and do not last. Just leave it where it is and do not mess with the hydraulic circuit.

 

Add a mechanical switch at the pedal box under the bonnet.

 

Replacement on a Girling car is simple if you can bend up a bracket to hold the replacement mechanical switch in a position by the pedal box so when the pedal is pressed the switch goes 'live'. The wiring will be long enough but may need Lucar terminals adding.

 

On a Lockheed car you will need to extend the wiring from the hydraulic switch to the mechanical one. Same deal with a switch holding bracket though.

 

Moderns like the TR4A have a bracket welded to the pedal box to accept the mechanical switch.

 

The bracket is merely wedged and gripped under the pedal box and bent so the switch plunger contacts the brake pedal clevis. You could get smart and rivet/screw the bracket to your pedal box/m.cyl bracket

 

The switch we are using is this one from a German Euro Box - http://www.ebay.co.uk/itm/230958745598?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

Cheers

Peter W

 

Here is my car using the TR4A pedal box and the German mechanical switch.

 

Edited August 5, 2016 by BlueTR3A-5EKT

[iain]

HI Austin

 

yes the feed to the rear of the car is down the drivers side, feeds the OSR lights and then traverses the rear apron to the other lights. Has your sidescreenstowage dislodged the wires/connectors.

 

Regarding the brake lights, test the switch with a multi-meter set to "continuity" across the terminals and get the boss to press the pedal...ign OFF. If it goes from no continuity to continuity with the pedal pressed its not the switch.

 

Good luck

Iain

[foster461]

If your wiring is standard Austin then no its not related - the indicators and brake lights both run from the 'A3-A4' fuse. The headlights and panel lights are on another circuit and are not fused at all , (except on US cars apparently).

 

If both the brake lights are out but the other half of the bulb works OK on sidelamps, it could be a problem wiith the feed from the hydraulic brakelight switch or with the switch itself.

 

Best to start by looking at the bulbs and bulb holders, make sure the bulbs are Ok - the solder pip can flatten after many years and cease to contact - and make sure they seat properly in the holder and that the holders are making a good earth connection - the panel lamp holders are a poor push-in fit .

 

The US TR3A's have a fuse in the sidelight/instrument-light circuit clipped behind the small instrument panel on the dashboard but there is no fuse in the headlamp circuit.

 

Stan