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LED question
Posted: Wed May 25, 2022 3:03 pm
by Devonrod
Is there anyway of using 12v LEDs as warning lights for the ignition and oil warning lights ? I was doing this on the RV8 and found out that you need an ordinary bulb in my system that was taken from a P6 Rover,18 ACR alternator ect, for it to work, I went ahead and put in an LED on the oil warning light only to find it flickers on at tick over, any suggestions please ?
Re: LED question
Posted: Wed May 25, 2022 5:31 pm
by Ian Anderson
Your oil pressure is extremely low at hot idle and the LED flickers.
An incandescent bulb takes Xx times longer to glow and the amount of current getting through does not allow it to do so.
Would be my guess.
Easiest fix is a slightly heavier oil but you then need to take it easy on warm up as it will be too thick.
Ian
Re: LED question
Posted: Wed May 25, 2022 8:31 pm
by stevieturbo
Generally the alternator excite needs a small load in order to work, hence an LED will not really suffice. Unless perhaps you can run a suitable resistor in parallel across it, although no idea how much it would need.
Re: LED question
Posted: Wed May 25, 2022 9:48 pm
by ChrisJC
The instrument cluster from a Montego / Metro / Maestro / Fright Rover / Discovery 1 has a resistor in parallel with the charge light, presumably so if the bulb goes, the alternator will still work.
I don't know the value however.
Chris.
Re: LED question
Posted: Thu May 26, 2022 3:52 pm
by Devonrod
Thanks for the replies, guess I am sticking with the old bulbs, as to the oil light flickering, its a rebuilt brand new top hat 4.6 with Valvoline VR1 20/50 with some Comp cams zinc additive, only done about 1000 miles, but it is my old SD1 front cover and oil pump although I went through it and seemed fine, I want to use a dissy for looks as its in a hot rod !
Re: LED question
Posted: Fri May 27, 2022 8:54 am
by DaveEFI
A small LED will light on a tiny current, so could be increasing the load on the switch with a parallel resistor would stop it flickering.
Re: LED question
Posted: Fri May 27, 2022 6:42 pm
by richardpope50
Ask this guy
https://www.bettercarlighting.co.uk/
He does a lot of replacement LED bulbs for standard bulbs and probably will have the right one. I used hime to replace all my side and indicator bulbs for LED ones and they were simply a straight swap.
Re: LED question
Posted: Tue May 31, 2022 1:34 pm
by SuperV8
I'm using LED bulbs for my warning lights - charge and low oil pressure and works fine. Also have a blue one for my main headlights - which reminds me - is too bright at night so needs a resistor to dim it a little.
My low pressure is a switch - on or off so easy for an LED. I also have an analog pressure gauge.
Can't recall exactly regarding my charge warning - I used to have the amber light on until I blipped the throttle to get the alternator self exciting/charging with the old Lucas alternator - once charging it would stay charging - but now i'm using a tiny alternator from something like a Kubota tractor I don't have to do blip the throttle to start the alternator - just self excites.
Re: LED question
Posted: Wed Jun 01, 2022 3:38 pm
by Devonrod
SuperV8 wrote: ↑Tue May 31, 2022 1:34 pm
I'm using LED bulbs for my warning lights - charge and low oil pressure and works fine. Also have a blue one for my main headlights - which reminds me - is too bright at night so needs a resistor to dim it a little.
My low pressure is a switch - on or off so easy for an LED. I also have an analog pressure gauge.
Can't recall exactly regarding my charge warning - I used to have the amber light on until I blipped the throttle to get the alternator self exciting/charging with the old Lucas alternator - once charging it would stay charging - but now i'm using a tiny alternator from something like a Kubota tractor I don't have to do blip the throttle to start the alternator - just self excites.
I have LED running lights on the dash to show where the switches are in the dark, used one of these controllers to dim them, it can also make them flash if you want to !
https://www.ebay.co.uk/itm/193990955923 ... BM2JTF_qNg
Re: LED question
Posted: Tue Jun 07, 2022 8:47 am
by SuperV8
Devonrod wrote: ↑Wed Jun 01, 2022 3:38 pm
SuperV8 wrote: ↑Tue May 31, 2022 1:34 pm
I'm using LED bulbs for my warning lights - charge and low oil pressure and works fine. Also have a blue one for my main headlights - which reminds me - is too bright at night so needs a resistor to dim it a little.
My low pressure is a switch - on or off so easy for an LED. I also have an analog pressure gauge.
Can't recall exactly regarding my charge warning - I used to have the amber light on until I blipped the throttle to get the alternator self exciting/charging with the old Lucas alternator - once charging it would stay charging - but now i'm using a tiny alternator from something like a Kubota tractor I don't have to do blip the throttle to start the alternator - just self excites.
I have LED running lights on the dash to show where the switches are in the dark, used one of these controllers to dim them, it can also make them flash if you want to !
https://www.ebay.co.uk/itm/193990955923 ... BM2JTF_qNg
Interesting, thanks.