please help! sealed beam problems

[Mechman]

hi guys
i have an FJ40 with sealed beams. i have rewired the truck and all is working well. i am trying to fit some spotties and want to take the signal to trip the relay from teh main beam... as you would. but, these sealed beams are strange. even when on low beam i am still getting votlage out or the highbeam terminal. its not much, but its enought to trip the relay.. so spots are on all the time.

any ideas????

scratchin me ead here....

Rob

[murcod]

Have you tried wiring the relay coil across the high beam filament terminals (rather than just using the +ve off the high beam and the chassis earth)?

It may work.

[Mechman]

umm.. as in the relay earth and the switching positive to the relay across the fillamant?

[chimpboy]

Toyotas (I think, I hope it's only the older ones) run a really shitty arrangement which is negative switched and weird in other ways as well.

There's a diagram floating around somewhere that shows how it works.

Frustrating and annoying, lemme see if I can find the diagram. I've posted it here before as others have as well.

Jason

[murcod]

umm.. as in the relay earth and the switching positive to the relay across the fillamant?

Find the two terminals on the back of the headlight that are for high beam and wire the relay coil onto them and see if that helps. By the sound of it currently you have the relay coil wired to the chassis (or battery negative) and the postive wire from the headlight high beam?

My theory is your headlight high beam will only have 12v across it when the high beam light is on, therefore if you wire the relay directly across it everything should work. It shouldn't matter how the headlight is wired if you do it this way.

[Mechman]

thanks chimpboy.. that would be awsome. i am at my wits end here. i have even brought new lights incase it was a fault there.

[Mechman]

umm.. as in the relay earth and the switching positive to the relay across the fillamant?

Find the two terminals on the back of the headlight that are for high beam and wire the relay coil onto them and see if that helps. By the sound of it currently you have the relay coil wired to the chassis (or battery negative) and the postive wire from the headlight high beam?

My theory is your headlight high beam will only have 12v across it when the high beam light is on, therefore if you wire the relay directly across it everything should work. It shouldn't matter how the headlight is wired if you do it this way.

umm, sorry for my ignorance here.. i have 3 terminals on the sealed beams.. earth, high and low. both these trip the relay to turn on the spotties.. even if its only switched to lowbeam.

does that make sense murcod?

[chimpboy]

thanks chimpboy.. that would be awsome. i am at my wits end here. i have even brought new lights incase it was a fault there.

Here 'tis:

http://www.safari4x4.com.au/80scool/tec ... iring.html

The way it works is screwy, as I recalled. The coil of the main relay is negative switched by the stalk - this determines if there are any lights on at all, high or low. However even though it is negative switched, it switches the positive power to the lights. However - the selection of high or low beam is done by switching the negative between the two. If you find that confusing - I can't blame you.

If it were my car, I would ditch the lot and rewire it. But if you don't want to do that, then what Murcod said is right as usual. Grab +ve and -ve from the high beam. Run one straight to your relay, and the other to the cabin, through a switch, and back out to the relay. These go to the relay coil (85 and 86). Then send some nice beefy +ve to the relay from the battery, to terminal 30, and then from terminal 87 to your spotlights.

Then just ground the spotlights as normal.

Let us know if that doesn't make sense.

Jason

[chimpboy]

umm, sorry for my ignorance here.. i have 3 terminals on the sealed beams.. earth, high and low. both these trip the relay to turn on the spotties.. even if its only switched to lowbeam.

does that make sense murcod?

Are you sure you don't have high (-ve), low (-ve), and +12V?

Jason

[murcod]

I think Jason just explained what I was on about (I couldn't remember the relay terminal numbers to give more detail )

When you've got high beam on you should have 12v across two terminals on the back of your headlight. These two are the ones to try wiring across the relay coil to use the method I suggested. You can run one of them back into the cabin and put a switch into the line as Jason said to keep it all legal.

[ORSM45]

i know late model fj 40s have a positive switched headlight (2 positives for low/high beam, and a negative common) and 60 series have a negative switched headlight. (positive common)

i would do as murcod suggested. use the 2 wires that cross the high beam filament. doesnt matter which wire has +ve or -ve as a switch will break the circuit no matter where its positioned.

[Mechman]

hmm. i must have a bigger problem than i thought. i have tried as sugested but as soon as the lights come on, the spots also work. i have a voltage across both terminals as soon as the lights are turned on, all be it a small one across the highbeam in low. it is still enough to activate the relay.

any other ideas?.. or should i just manually activate them... after the RWC of course.....

[murcod]

How high is the voltage?

You could put a couple of diodes in series with the relay coil wire, each one will drop approx 0.6v, just keep adding them until the relay doesn't come on with lowbeam. Diodes will only conduct in one direction so you need to make sure the anode has the highbeam +12V on it and the cathode is on the side of the relay coil. The cathode end has the band on it.

Something like a 1N4004 will do the job:

http://www1.jaycar.com.au/productView.a ... BCATID=388

[Mechman]

thanks murcod... will give that a go.

cheers