Hot relays - L series

YouTube · Post by **El_Freddo** » Wed Mar 05, 2008 8:57 pm

Hey all,

I've been trying to work out whats wrong with my low beam - won't work when i turn the lights on or dim from high beams (sorted this problem - its the common dirty/worn terminals in the stalk).

What I did find was that the relays that hide up in the dash above the fuse box get really hot - hot enough for you to only hold for a little while. The quesiton is, does anyone know if this is normal or is there something wrong??? All relays (about 6) were of similar temp.

Any info on this would be good.

Cheers

Bennie

fredsub · Post by **fredsub** » Wed Mar 05, 2008 10:29 pm

If i recall,they do get rather very warm. Its disturbing that one is on the accessories circuit too.
Warm relays means wasted energy, they aren't very efficient. The whole lighting wiring is crap in the L series....

Gannon · Post by **Gannon** » Thu Mar 06, 2008 2:53 pm

If you are electrically minded, rewire them so the relays are just behind the headlights, and run directly from the battery, this will reduce the voltage drop between the battery/dash/lights. Ive done it, and my lights seem to be brighter.

BrennyV · Post by **BrennyV** » Thu Mar 06, 2008 4:07 pm

i know they do get hot. spesh in my's!

YouTube · Post by **El_Freddo** » Mon Mar 10, 2008 11:46 am

Suparoo wrote:If you are electrically minded, rewire them so the relays are just behind the headlights, and run directly from the battery, this will reduce the voltage drop between the battery/dash/lights. Ive done it, and my lights seem to be brighter.

This is on the list of things to do soon. Did you remove those relays (for the lights only) and send the wires from these old relays to the front of the car with the new relays (with power straight from the battery) running the headlights, or did you just put in the new relays up front with the old headlight wiring being the "reference" voltage to switch them on and off (effectively turning the lights on and off too)?

Clear as mud?

Some of those relays get rather hot. I noticed the other day with out the lights on that two of them were cold, the rest were still hot...

I also fixed my low beam issue. As it turns out i can't get my steering wheel off, even with a centre pull

So i un-screwed the indicator mech from the steering column, spun it around til i could get at the contacts and blew some graphite lubricator on them. Worked really well but would not recommend this fix. The graphite was too much, and as a result it would cause smoke as the excess burnt off. Its concerning that these contacts get that hot. Could there be something else wrong with my system?

Cheers

Bennie

fredsub · Post by **fredsub** » Mon Mar 10, 2008 12:44 pm

The contacts shouldn't get hot, except the high beam current,which does go through the contacts - when you push forward the stalk. Otherwise they are
simply driving the relays. I'v not measured what the activating current of those relays are and its too late for me now, maybe someone else?
The horn current goes thru contacts in the steering too,up to 10amp initial current IIRC, it proved unreliable in my Lseries too, replaced with a relay then no problems.

discopotato03 · Post by **discopotato03** » Mon Mar 10, 2008 12:46 pm

Most people just use the existing wiring near the headlights to trigger new relays and better power supplies .
If you look at the original relays they don't always share the same earth as the component they switch . You need to emulate what they did with the earths to make it work properly with dash lights etc .

Cheers A .

Gannon · Post by **Gannon** » Mon Mar 10, 2008 4:36 pm

El_Freddo wrote:This is on the list of things to do soon. Did you put in the new relays up front with the old headlight wiring being the "reference" voltage to switch them on and off (effectively turning the lights on and off too)?

Yep, thats what i did

YouTube · Post by **El_Freddo** » Mon Mar 10, 2008 10:03 pm

Thanks everyone for your input.

Suparoo wrote:Yep, thats what i did

Cheers gannon, this just made the process a lot easier

Bennie

foxx510 · Post by **foxx510** » Thu Mar 13, 2008 11:24 am

Where it gets a bit confusing with rewiring headlights is that the standard setup switches the earths to the globes to turn the headlights on and off, whereas when you rewire it you will be switching the positives. In effect your are putting the relay trigger coil where the headlight globe used to be in the circuit. Then you have a decent, high current set of contacts to switch your new wiring with.

YouTube · Post by **El_Freddo** » Thu Mar 13, 2008 11:57 am

That is correct. I will still be wiring them so that they turn off with the ignition. here's the diagram i will be following. With the use of two relay per light (one for hi beam, one for low)...

There will not be a dash mounted switch, this will just be a wire that becomes live with the lights on or with the ignition and obviously the standard light won't be there...

Let me know if this idea will not work. I have my driving lights setup in this way (note the layout of the diagram - and the dodgy drawing, shoulda used paint...) I don't know if this will effect the way they switch on and off but if it does i'll cross that path when i come to it...

Cheers

Bennie

discopotato03 · Post by **discopotato03** » Thu Mar 13, 2008 12:34 pm

El Freddo I haven't looked at the factory manual to see how Subaru wires headlights . Many cars of that era used the rotary switch to power up the positive side of the circuit and the stalk position to switch the earth for either high or low beam filaments .
Resistance in either the power or earth side costs lighting energy and shows up as hot wiring or relays . You need to do a voltage drop test on both sides to see where areas of high resistance are . The 20 odd yr old relays probably don't work as well as they did when new .

Cars used to be set up so that the lights would work regardless of the ignition system being powered up or not . It's a safety feature put in place so ignition system power failures don't take the lights with them .

I'll look at the 87 manual and see what they did . A more electrically minded friend can probably test the circuits to see how my RX is , I know the headlight plugs get a bit hot .

Cheers A .

YouTube · Post by **El_Freddo** » Thu Mar 13, 2008 12:58 pm

discopotato03 wrote:Cars used to be set up so that the lights would work regardless of the ignition system being powered up or not . It's a safety feature put in place so ignition system power failures don't take the lights with them.

the "gen 2" L's must have the ignition in the on position for the lights to work. Holden got around this by hooking the drivers door into the system - once the ignition is turned off the drivers door must open to turn the lights off. Where as my L's lights can be on for a week and I don't know it (unless i check the switch)...

The relay's only need a little bit of power to switch them on, so i'll probabily just use the old system wired properly to make the new relay system work properly. Only problem being that if the old system dies, so does my new one. Ultimately replacing the old system would be the go, but I don't have the time to pull it all down to re-wire in the original switches as it should be done.

One day...

Bennie

discopotato03 · Post by **discopotato03** » Thu Mar 13, 2008 1:50 pm

From what I can see 5 relays live under an L MPFI dash . Two are ignition and fuel pump relays so I gather some or all of the other 3 are for lighting .

The fuse panel and ignition switch and stalk are in the same general area so all "localised" .

The headlight wiring runs inside the same loom as the engine control stuff , you'd never cut it open to get at it but theres nothing to stop you running the 3 or so new wires taped or cable tied to the outside of this loom down to the headlight connections .
If you didn't feel like pulling the gard off it could even go through the rubber grommet near the drivers side strut tower and down the drivers side of the bay to where the main loom re appers near the radiator .

I'm guessing that there are 3 wires , 1 switched positive and 2 switched earths .

It sounds like 2G L's pick up power from the ignition switch where 1G's get permanent power from the fuse panel .

Will check that tomorrow .

Cheers A .

YouTube · Post by **El_Freddo** » Thu Mar 13, 2008 4:46 pm

discopotato03 wrote:From what I can see 5 relays live under an L MPFI dash . Two are ignition and fuel pump relays so I gather some or all of the other 3 are for lighting .
It sounds like 2G L's pick up power from the ignition switch where 1G's get permanent power from the fuse panel.

Think my MPFI loom has 7 of those relays under the dash - there's a sorta separate loom for the other 2, if that makes sense (like a fork in the loom for the two sets of relays...)

My sisters L's (84 gen1) lights stay on wether the ignition is on or off... I don't know how many relays this has.

My old carbie loom has 5 relays i think, it defenetly doesn't have as many relays in that area. The headlights also turn off with the ignition with that loom (88')... This is defenetly something that was upgraded with the dashboard layout/grill and the other little bits an pieces between the early and later L's...

Cheers

Bennie

Gannon · Post by **Gannon** » Thu Mar 13, 2008 5:44 pm

ive just made up a new headlight loom for my car. i will post pics when i finish it. I cut up an old vortex loom i found lying around.... which reminds me..

Discopotato03... do you want the remains of my vortex loom, i think it is an 88 turbo.

discopotato03 · Post by **discopotato03** » Thu Mar 13, 2008 8:13 pm

Yes the actual engine loom to the injectors/TPS etc would be very handy , especially if it has the two large round loom plugs and the knock sensor connection .
If it was 88 and AWD should be to suit arachnid manifold too .
Let me know what you want for it , I don't want to cut up the 87 turbo Vortex loom I have if I can help it - gold for an 87 Vortex owner .

I removed the headlight wiring I had in the 4P Auto 88/89 L loom I have and its coiled up in the cave somewhere . It would make a good template for rewiring lights .
Its possibly a little more work but replacing the std wiring would be neater and leave us with a less cluttered engine bay . Those round under dash relays could easily be replaced with common square Bosch type ones in base mounts as well .

Cheers A .

Gannon · Post by **Gannon** » Tue Mar 25, 2008 9:34 pm

Ok... i made up a better loom for my headlights, works a treat. I am yet to test voltages with the engine running.

I designed it with bullet connectors so if i wanna remove the new loom, i can just plug the factory lights back in.

This shows the complete loom, i even designed in a relay plug for my driving lights that only come on with the highbeam.

I will take some more pics of it completed.

One thing i did notice is that both low beams blew within a week of each other not long after hooking it up, which could be a coincidence, or because they were old and frail from lots of use. I leave my lowbeams on all the time

YouTube · Post by **El_Freddo** » Mon Mar 31, 2008 5:11 pm

Well, I found out why my low beams weren't working properly. Last week my low beams were the only things to work but I didn't have time to find out what it was that caused the problem so frustratingly had to drive with low beams only.

On my way home from eildon friday night the problem reared its ugly head after getting the high beams working again. I could smell something burning, thought it was still the paint on the new radiator... Till my lights went out again. Found out it was the earth wire to the hi/low beam light switch, it had become so hot that it melted the soilder and broke the link which = no lights at all (except dimmers). So I wedged it in so that I at least had low beams.

Once home I finally got my steering wheel off and took the hi/low switch off to be re-soildered together... I did a good job, got some heat into both parts for a solid joint. While I was putting the car back together I ran the engine with the high beam lights on. The joint got pretty hot again (I couldn't leave my finger on it) until within five minutes it broke.

We now think that after putting the graphite powder on the contact terminals the resistance on the high-beam contact was so great that the heat from this melted the soilder. I'll be cofirming this later in the week when I get back home to fixt the problem with some emery paper on the contacts and another re-soilder.

As for my lights upgrade - I'll be using the plug under the dash to the hi/low unit direct to the new relays up front... I'll use the exisiting power source to the switch but re-route the wires to the new relays then to the lights themselves. This will allow me to do the same as you Suparoo - unplug the new wiring to revert back to the standard if needed.

Cheers

Bennie

PS Suparoo, why'd you stick to the factory relays?