HOW-TO: Rewire fog lights as DRLs - A/T only

[flcruising]

This modification pulls power off the automatic transmission relay right next to the fog relay - this is why it's only for the a/t vehicles.

1) Clip off the power leg of the fog relay.

2) Solder a small gauge (22+AWG) 4" jumper wire from that clipped leg to the base of the centermost leg of the a/t relay right next to it (don't clip that leg).

3) Plug them back in.​

See the picture below. I drew what was happening on the inside cover of the fuse panel to clarify. This view would simply require the relays to be flipped forward and pushed back into place. The fogs now come on with the key to RUN. The fog switch still works the same and the the High Beams still turn them off.

More images to clarify...

 

[flcruising]

For those of you concerned...

The power drawn from the A/T Relay is only for energizing the fog relay, not for powering the fog lights.

The current the relay draws is minimal (mA), and it's pulling from the switched POWER, therefore it's not putting any extra load on the BCM/ECM which controls the A/T relay.

^I guess you could call that a disclaimer^ (thumb)

 

[Davebert]

Nice mod, easy to revert back to stock. Wish I had though of it .

 

[flcruising]

Well, it is if you follow this procedure and source the power from the A/T relay instead - http://www.mazdas247.com/forum/show...ire-fog-lights-to-come-on-with-parking-lights

Since you clip the leg of the fog relay it renders it useless if you remove the jumper wire. You could just get yourself a spare set of relays.

 

[Fivo]

Very impressive. It looks like the headlight DRL's would still come on though.

 

[flcruising]

We in the US don't have headlight DRL's.

If we did, I wouldn't have done this.

 

[Jetmech]

Thanks for the tip as this gives me a bypass of my BCM which is screwed up and not allowing my fog lights to work at all. I didn't do the same as you with regards to picking off the A/T but I had lost a ground signal so I piggy backed the leads like you and grounded off the chassis. The only thing is the fogs are always on now whenever the DRL are on or the Headlights.

Cheers

 

[flcruising]

You sure it was from the BCM, and not the fog switch?

 

[jeff524]

how about using the high beam as DRL instead of the fog

 

[flcruising]

If you want to blind people sure, but factory DRL's that utilize the high beams are running through a PWM circuit at lower power. Some say about 60%. Not sure how you'd do this without some new electronics.

 

[miami]

Anyone know a workaround like this for the second gen cars?

 

[flcruising]

What you want to do is:

1. Turn ON headlights
2. Turn ON fog lights
3. Pull out the fog relay
4. Check terminals for 12V
5. Switch OFF fog lights
6. Check terminals again for 12V

Report back your results.

 

[kickin_81]

OP, do you have a picture of the M5 with the fogs on as DRLs? And have you had any electrical problems or cautions after performing this mod?

 

[flcruising]

No electrical issues.

See post #4http://www.mazdas247.com/forum/show...RLs-A-T-only&p=5454804&viewfull=1#post5454804