Outrage Posted November 25, 2006 Share Posted November 25, 2006 Hi all, I've found a Lucas 6RA 20A relay behind the small central console in the middle of the dash it's got one red/white wire which is fed from the ignition, 1x black wire which i presume is the earth and one black/white wire which dissapears into the wiring loom behind the dash. Is this something to do with the brake failure light? This is fitted and doesn't appear to be visible on the series III schematic either - was it an optional add on? ta, Lee Quote Link to comment Share on other sites More sharing options...
rtbarton Posted November 25, 2006 Share Posted November 25, 2006 Hi all,I've found a Lucas 6RA 20A relay behind the small central console in the middle of the dash it's got one red/white wire which is fed from the ignition, 1x black wire which i presume is the earth and one black/white wire which dissapears into the wiring loom behind the dash. Is this something to do with the brake failure light? This is fitted and doesn't appear to be visible on the series III schematic either - was it an optional add on? ta, Lee The red/white wire from the ignition switch is usually the feed to the starter solenoid, so it looks like someone has fitted a relay to operate the solenoid. Check to see if the black/white wire ends up at the solenoid itself. The brake failure light was an option, have you downloaded the PDF manuals? It's in there. The warning light is operated by some or all of 1) test switch, 2) fluid level switch, 3) PDWA, 4) loss of vacuum or 5) pedal travel switch. Quote Link to comment Share on other sites More sharing options...
Outrage Posted November 25, 2006 Author Share Posted November 25, 2006 The red/white wire from the ignition switch is usually the feed to the starter solenoid, so it looks like someone has fitted a relay to operate the solenoid. Check to see if the black/white wire ends up at the solenoid itself.The brake failure light was an option, have you downloaded the PDF manuals? It's in there. The warning light is operated by some or all of 1) test switch, 2) fluid level switch, 3) PDWA, 4) loss of vacuum or 5) pedal travel switch. Hi Roger, The Red/White wire is a feed off the same terminal that provides power to the instruments etc (white wire). This is in addition to the Red/White wire that goes to the starter motor solenoid which i have checked works ok (i am having problems with the ignition switch as well!) this wire is smaller than the starter solenoid wire. I don't have a test switch as i've seen on other vehicles just an indicator with "BRAKES" on it. The only other black/white wires i can find on the vehicle go down to the shuttle valve on the brake lines so i'll assume it's for that. Strange setup! Cheers, Lee Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 26, 2006 Share Posted November 26, 2006 I'd be very wary of relying on wiring colours to be correct in a Series - it's old and it was built by BL, the possibilities for error are huge your only surefire way is tracing the wires. I had the brake warning setup on mine, it never worked and the wiring certainly wasn't as per the manual Quote Link to comment Share on other sites More sharing options...
western Posted November 26, 2006 Share Posted November 26, 2006 Hi all,I've found a Lucas 6RA 20A relay behind the small central console in the middle of the dash it's got one red/white wire which is fed from the ignition, 1x black wire which i presume is the earth and one black/white wire which dissapears into the wiring loom behind the dash. Is this something to do with the brake failure light? This is fitted and doesn't appear to be visible on the series III schematic either - was it an optional add on? ta, Lee It's the brake failure warning works during the start cycle as a bulb & system check, IIRC it was fitted to late S3 when dual circuit brakes were fitted [front - rear split] Quote Link to comment Share on other sites More sharing options...
rtbarton Posted November 26, 2006 Share Posted November 26, 2006 Hi Roger, The Red/White wire is a feed off the same terminal that provides power to the instruments etc (white wire). This is in addition to the Red/White wire that goes to the starter motor solenoid which i have checked works ok (i am having problems with the ignition switch as well!) this wire is smaller than the starter solenoid wire.I don't have a test switch as i've seen on other vehicles just an indicator with "BRAKES" on it. The only other black/white wires i can find on the vehicle go down to the shuttle valve on the brake lines so i'll assume it's for that. Strange setup! Cheers, Lee Sounds like an unofficial add-on. Really hard to to tell wirhout looking at it, especially with the altered igntiiton switch. Sometimes the brake test switch is combined with the warning lamp, have you ried pressing the lamp? Quote Link to comment Share on other sites More sharing options...
rtbarton Posted November 26, 2006 Share Posted November 26, 2006 It's the brake failure warning works during the start cycle as a bulb & system check, IIRC it was fitted to late S3 when dual circuit brakes were fitted [front - rear split] Mmmmmmm? Didn't think S3 were that sophisticated, according to the manual the only check on the brake warning light was a push switch. I suppose if the relay was connected from ignition to oil pressure switch (W1 & W2) it would close when the ignition was switched on and then open once the engine was running, thus the contacts (C1 & C2) could be used to test the brake warning light. Quote Link to comment Share on other sites More sharing options...
rtbarton Posted November 26, 2006 Share Posted November 26, 2006 Hope this helps Brake Warning light Quote Link to comment Share on other sites More sharing options...
Outrage Posted November 28, 2006 Author Share Posted November 28, 2006 Hope this helpsBrake Warning light Hey all, thanks for the replies. It doesn't seem to be harming anything so i'll just leave it be for the moment. I was just pondering the elastictrickey on this car whilst removing the rest of the bodged together wiring. Roger, Hadn't seen that one before, Is that out of the workshop manual? That's the circuit i'd seen before on other vehicles. Western, That seem's to make sense and looking at the wiring I think that was what was intended although it certainly doesn't work! That would also explain why my system doesn't have the test switch. Has anyone got an official diagram for this circuit? Cheers all. p.s. what's the can do on the engine side of the bulkhead, its got three terminals with three green wires - Thought it may be the indicator flasher but i've just found that in the bottom of the dash with two wires on it. Lee Quote Link to comment Share on other sites More sharing options...
rtbarton Posted November 28, 2006 Share Posted November 28, 2006 Roger, Hadn't seen that one before, Is that out of the workshop manual? That's the circuit i'd seen before on other vehicles. Yes, it's the PDF manuals, which I downloaded a while ago, fro lRO forum IIRC. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.