When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Anyone wired fog lamps to work as Daytime Running Lights? Gen III
Mitsubishi Montero & Montero SportThis sport utility vehicle offers more size than the other Mitsubishi SUVs, but manages to keep a sporty look and comfortable feel, unlike many larger SUVs.
Anyone wired fog lamps to work as Daytime Running Lights? Gen III
SOLVED: Anyone wired fog lamps to work as Daytime Running Lights? Gen III
Hi:
I've searched a bit and there are lots of articles re: doing this on other makes, but I can't find any reference for our vehicles. On one of my other cars it was just pulling a relay and adding a jumper.
Does anyone have any info or experience doing this?
Hi Hunter: Coincidentally, I decided to get back on this project and was out tracing circuits when your post hit yesterday. Turned out to be pretty straightforward. I have some photos and will post the details later.
More details on this project, as promised...............
Disclaimer: I’m not a professional auto technician and this is not a suggestion that you should attempt to modify your vehicle’s factory wiring. I’m just sharing details of an experiment I attempted on my US Federal version 2005 Montero Limited. I do not know if the wiring points I found are the same, or different from, any other year or model. Do not attempt this yourself unless you are comfortable with automotive wiring and circuit testing and have the proper test equipment to insure that any mods you make will not cause damage. Also, I do not yet have any long term reliability info on any possible side effects, e.g. early fog lamp burn out, weaker cranking power, etc.
OK, with that out of the way, here’s what I found and did:
I located and removed the Fog Lamp Relay, R6, which is on the right side of the engine compartment fuse panel. The socket from which it was removed is diagramed in the first photo.
In normal operation, constant (unswitched) +12v is supplied to one side of the relay coil, and also to one side of the relay switch contacts. The other side of the coil is “floating” – neither positive nor connected to ground. When the Fog Lamp Switch on the dash is pushed, control circuitry connects that floating coil end to ground [only if the low beam headlights are on,] thus energizing the relay. This closes the internal relay contacts and sends power to the fog lights via the remaining socket.
The goal was to see if the fog lights could be used as DRLs, which would require them to be on even if the headlights were not. It seemed the easiest way to do this was to find a source of switched 12v and jumper this directly to the socket that goes to the lamps. This would bypass the relay and the dash switch completely and turn on the lamps any time the key was in the ACC, or run mode.
Another, more complicated, solution would be to add a new generic accessory relay and wire it up so that it grounds the floating contact when the key was on. This would retain the fog lamp relay, but the dash switch would be redundant. This is probably the more elegant option as it does not involve adding the fog lights to some other load in another switched circuit. However the jumper approach was a lot easier so I decided to try that first.
So, in search of a good source of switched power, I found something interesting. There is supposed? to be an identical twin relay - for the horn, on the left side of the panel as shown in the 2nd photo. BUT, even though it’s shown as being present various web diagrams, as well as on the lid of the panel, in my case the relay was missing. I've always had a working horn so this is curious. As an experiment, I plugged the fog lamp relay into that horn socket and nothing changed – horn worked the same as always. SO, it’s a mystery. Perhaps some of you can check to let me know if ’05 models don’t have that relay for some reason.
But that’s beside the point for this project, because, coincidentally, that socket does have switched power present in the female plug connectors. And, it’s a known circuit (that is very rarely used) - with its own fuse. So, I felt fairly comfortable adding the fog lamps to the horn circuit with a short jumper as shown in photo 3. Note that the in-line fuse is probably overkill, since the horn circuit is fused, but I had it on hand and decided it couldn’t hurt. FWIW, I tried laying on the horn for a long time to see if the combined current drain from the horns + the fog lamps would blow the 10A horn fuse, and it did not.
So that’s about it. I’m still considering going the add-on a relay route, but will keep this in place for a while. And I’m certainly open to suggestions and/or critiques if anyone sees anything amiss in all of this.
BTW, I was surprised to note that even with the switch and relay gone, the green icon indicator in the instrument panel still stays lit. Apparently it's triggered directly off of the hot side of the lamps, not from the switch.
Great writeup. I've always wondered about this for our rigs as I was never really able to find anything online. Thanks for the detailed process and pics as well.
Thanks Dentar! If you have a chance, please check to see if you have a horn relay installed. That is still puzzling me. I'm the 2nd owner and the first one was a dealer-service only type. So I doubt they were ever pulling relays for some reason.
Also, FYI, I cranked the fog lamp aiming adjustment to the lowest position to make sure I'm not annoying anyone.
Thanks for checking - so it's still curious, but at least I'm not alone.
AND, the plot thickens since I found this drawing on line (original source not included)
I checked, and, sure enough, those two rear relays do control the regular and alarm horns. And they are also pictured on the lid. All I can think of is that some Montero / Pajero / Shogun models used the empty socket and not the ones in the rear. Maybe base models without alarm systems? We only got the Limited here in the US. Anyway, I'm not going to chase it further as long as everything is working