smitch6 Posted June 9, 2020 Share Posted June 9, 2020 I have a standard lucas ignition on my bmc diesel engine boat. the ignition is 1 end and the engine is the other. I am changing the ignition for 2 switches and a push button start as the ignition keeps spinning, new ignition panel So it will be 1 switch will ignite the ignition, 1 momentary switch will heat the glow plugs, push button will start the engine. another option i have is 1 switch will ignite the ignition, i then have a timer & relay to heat the glow plugs on this switch. timer and this is the relay The stop isn't on the ignition How do i wire the switches etc pls? Quote Link to comment Share on other sites More sharing options...
smitch6 Posted June 9, 2020 Author Share Posted June 9, 2020 this is the back of the ignition switch Quote Link to comment Share on other sites More sharing options...
Vaughan Posted June 9, 2020 Share Posted June 9, 2020 Sounds to me as though you are complicating matters for no extra advantage. You can easily stop the ignition switch from turning by making up a bracket under the dash. Something similar to the bracket on the gauge in the bottom right of your photo, screwed into the dashboard. Just make sure it is insulated from the terminals! The starter solenoid on a BMC is also a relay, so you don't need much current to feed it from the key. The glow plugs will take about 25amps total, so a relay near the engine will avoid volt drop in the circuit. You will probably find that the key is fed from the terminal, battery side, of the starter solenoid. I assume the other large brown wire in your photo goes to a fuse box for other appliances. 1 1 Quote Link to comment Share on other sites More sharing options...
Vaughan Posted June 9, 2020 Share Posted June 9, 2020 I have just remembered! The key will have a round black backing plate, which says "off run heat start" and this has a keyway, to stop it turning on the base of the key. So all you have to do is screw the plate onto the dash with two small screws and hey presto! If this plate is missing I imagine you can easily order it as a spare part. 1 Quote Link to comment Share on other sites More sharing options...
OldBerkshireBoy Posted June 9, 2020 Share Posted June 9, 2020 I replaced my dash and fitted new gauges and switches this year and still have the old bits so send a PM if interested. 1980 Bounty with 1.5 BMC engine Quote Link to comment Share on other sites More sharing options...
ZimbiIV Posted June 9, 2020 Share Posted June 9, 2020 Sounds like the thread has gone on the locking ring. Just change the ignition switch. Not that expensive and easier that faffing with rewiring. paul Quote Link to comment Share on other sites More sharing options...
Smoggy Posted June 9, 2020 Share Posted June 9, 2020 Those switches are about £16, not worth faffing about. Quote Link to comment Share on other sites More sharing options...
OldBerkshireBoy Posted June 9, 2020 Share Posted June 9, 2020 Not worth faffing about with? C`mon people please consider that we can do whatever we want on our own boats within the BSC. Quote Link to comment Share on other sites More sharing options...
Oddfellow Posted June 9, 2020 Share Posted June 9, 2020 This does seem like an incredibly complicated solution. Add to that the fact that a BMC 1.5 often requires different levels of preheating (or no preheating if its warm) then the auto-preheat solution is probably not a solution at all and will just introduce unnecessary battery drain on a warm engine and possibly make it impossible to start after a very cold night of having been left for months. There will be a lot of wiring to get this to work and I doubt that it will work as well as fixing the existing problem. 3 Quote Link to comment Share on other sites More sharing options...
annv Posted June 9, 2020 Share Posted June 9, 2020 Hi Fit another/or replace the washer under the threaded collar of switch so nut will screw up tight to stop switch turning, new dash is properly thinner than old one.John Quote Link to comment Share on other sites More sharing options...
smitch6 Posted June 9, 2020 Author Share Posted June 9, 2020 4 hours ago, Vaughan said: I have just remembered! The key will have a round black backing plate, which says "off run heat start" and this has a keyway, to stop it turning on the base of the key. So all you have to do is screw the plate onto the dash with two small screws and hey presto! If this plate is missing I imagine you can easily order it as a spare part. nope no plate, 3 hours ago, ZimbiIV said: Sounds like the thread has gone on the locking ring. Just change the ignition switch. Not that expensive and easier that faffing with rewiring. paul thread hasn't gone, i've got a brand new one also, but as you turn the key to start it just undo's and comes loose no mater how tight you have it. 3 hours ago, Smoggy said: Those switches are about £16, not worth faffing about. i have already bought a new one and yes it is worth faffing about....... 2 hours ago, OldBerkshireBoy said: Not worth faffing about with? C`mon people please consider that we can do whatever we want on our own boats within the BSC. thankyou for backing me up much appreciated 2 hours ago, FreedomBoatingHols said: This does seem like an incredibly complicated solution. Add to that the fact that a BMC 1.5 often requires different levels of preheating (or no preheating if its warm) then the auto-preheat solution is probably not a solution at all and will just introduce unnecessary battery drain on a warm engine and possibly make it impossible to start after a very cold night of having been left for months. There will be a lot of wiring to get this to work and I doubt that it will work as well as fixing the existing problem. even a warm engine will benefit from some type of preheat, it stops it smoking for one at start up, Quote Link to comment Share on other sites More sharing options...
smitch6 Posted June 9, 2020 Author Share Posted June 9, 2020 i want to change it because i have a round hole instead of the D so no amount of tightening will cure it, and because of the round hole it can be a pig to start as you have to tighten it time and wiggle the key. yes i have tried a brand new lock and it still does it. i would like something simple that i flick a switch and push a button, save messing about with having to fabricate a metal plate with a D in it, which i have tried but it isn't easy to make a D in a stainless steel plate...... Quote Link to comment Share on other sites More sharing options...
OldBerkshireBoy Posted June 9, 2020 Share Posted June 9, 2020 If you can`t find the backing plate then can you use a metal pin or use a screw to hold it in place or make up a tab on it`s own to suit and screw it in place? Was going to suggest Locktite Thread Locker but that will only hold the nut on the thread tight so maybe no use in this case. Quote Link to comment Share on other sites More sharing options...
Smoggy Posted June 9, 2020 Share Posted June 9, 2020 90 degree bracket screwed behind the panel with a hoseclip around ignition switch? Or a good dollop of epoxy behind switch then tighten and leave for a day to cure. 1 Quote Link to comment Share on other sites More sharing options...
Oddfellow Posted June 9, 2020 Share Posted June 9, 2020 1 hour ago, smitch6 said: even a warm engine will benefit from some type of preheat, it stops it smoking for one at start up, If you know better than a boatyard owner who knows these engines inside out and knows the wiring of a Lucas ignition switch without asking on a forum, I'll leave you to it. What you are taking about is fixing a round hole so that it has a flat in it to stop the ignition key from turning and you are doing this with some options that you're cobbling together something electrical. I would be gobsmacked if Brian Wards don't have a cover plate that you can screw over your round hole and solve the problem for less than a tenner. Even if they have to cut one for you, it will likely be cheaper than the sum of the parts you listed. 6 Quote Link to comment Share on other sites More sharing options...
OldBerkshireBoy Posted June 9, 2020 Share Posted June 9, 2020 Just had a look under the dash that Brian Ward did and can`t see anything so thinking it is the hole in the facia so as Andy said asking them to make a plate is perhaps the easier option. Quote Link to comment Share on other sites More sharing options...
smitch6 Posted June 9, 2020 Author Share Posted June 9, 2020 i have been searching and searching for days and days for a little plate and the only thing i can get is a small circular disc which wouldn't work as it's only 40mm so nothing to screw to the dash, never even thought of Brian Ward, just rung them and they can make me a plate for £30 as the ones they stock are only £3 but are small circular ones and won't work. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted June 9, 2020 Share Posted June 9, 2020 Try Peachments in Brundall. Quote Link to comment Share on other sites More sharing options...
grendel Posted June 9, 2020 Share Posted June 9, 2020 is it a lucas 128sa, if so i could probably print a mounting plate using dimensions from the internet. Quote Link to comment Share on other sites More sharing options...
smitch6 Posted June 9, 2020 Author Share Posted June 9, 2020 yes it is a 128sa..... the plate i'd need is about 90mm square, i'm not even bothered about the lettering, just need a plate to stop the switch turning so the D hole is the most important bit Quote Link to comment Share on other sites More sharing options...
smitch6 Posted June 9, 2020 Author Share Posted June 9, 2020 right back to the drawing board, i had been thinking i had to use stainless, which as you know is a nightmare to cut a D hole. so after chatting with Brian wards they said they use acrylic so i have ordered a round disc with the engraving on as they are only £5 posted, and ordered an A5 3mm sheet of black rigid acrylic off flebay for £3.50 and i'm going to have a god at mounting the disc onto the sheet and cutting a D out so fingers crossed Quote Link to comment Share on other sites More sharing options...
ZimbiIV Posted June 9, 2020 Share Posted June 9, 2020 Cut out the largest circle out, then the inner hole into this. Then cut another largest circle, cut a 'D' out of this place 'D' over above one cut this of the ring glue together the glue this under the dash. Refit ignition job done and no difference from the outside of the dash from before. Hope this makes sense. paul Quote Link to comment Share on other sites More sharing options...
annv Posted June 10, 2020 Share Posted June 10, 2020 could get a small sheet of ally file hole to suit fit on under side of dash glue to back of dash or large penny washer or roofing sheet washer file to fit be easier than stainless. John Quote Link to comment Share on other sites More sharing options...
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