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I'm having an odd issue where in-cabin relay 38 (passenger daytime running light) is clicking incessantly when the brakes are applied. This coincides with some other odd behavior:
Ignition on, car off 1. Step on brake, hear one click from relay 38 under passenger floorboard (from now on, "clicks" mean this relay). Subsequent steps on brake, no clicks. 2. Activating turn signal on either side makes both front blinkers blink very fast and dim. Back blinker blinks very fast on the correct side only. Either blinker or both may blink on the IP, with varying levels of brightness. Seems to me the speed also varies a bit, but always too fast. 3. Activating hazard lights seems ok. 4. Turn parking lights on: both turn signal arrows light up on the IP.
a. Turn signals/hazards act same as without parking lights on.
5. Turn headlights on: same behavior as #4 and #4a. 6. Turn lights to full off: several clicks heard, concurrent with bright/dim/bright/dim on the IP, clock, climate control display.
Car running 1. Step on brake, get 1-2 clicks. Take foot off brake, put back on, endless clicks, again concurrent with bright/dim changes in displays. Front turn signals blink fast and dim with these clicks also. Remove foot from brake, wait a couple seconds, reapply: same thing. Take foot off brake and reapply very quickly: a few seconds delay, then more endless clicks. 2. Turn signals/hazards: same behavior as above with car not running. 3. Turn parking lights on: Displays dim. Turn signals behave the same as before. But no clicking when stepping on brake. 4. Turn lights off: several clicks, same as when car not running.
I removed relay 38 and the clicking while braking has stopped, but the other issues described above persist (except for step 4 with the engine off / ignition on, where only the left turn signal indicator illuminates). That leads me to believe that the issue is not the relay itself, but something else that is triggering the relay to toggle. Maybe a bad ground somewhere? Has anyone else experienced this? I'm going to replace relay 38 because they are cheap and easy to swap but have low expectations that it's going to resolve the problem.
Update: I replaced relay 38 but there was no change; same with swapping R and L DRL relays. Removing both DRL relays settles down the odd behavior, but then I have no front turn signals or DRLs. The rear signals work, but flash quickly as before. Since this problem followed replacement of the left DRL bulb, I checked that to make sure both filaments were intact and that it was installed properly (not 180 degrees out). It's notable that the front parking and marker lights do not work, even with the DRL relays installed. Rears work just fine. I pulled fuse 6 (parking and tail lights) and confirmed that it's good. The rear tails and markers do not function with the fuse removed but work fine with it installed. With the parking light switch turned on, the DRLs turn off and there is no front parking, marker, or turn signal light on either side.
Sorry to hear this. I am experiencing the same type of issue on a 2001 z06 I picked up not too long ago. Very frustrating. I'm going to dig into the fuse box and start there (I've replaced every fuse and relay already). I believe water had been getting in the passenger side foot-well via clogged ducts. The poor car had sat outdoors for 3 years neglected.
yes. I have cleaned all the grounds. Replace the relays about four months back or replace the hazard switch. I read somewhere that there is a connector on the passenger side that can cause it so I’m gonna check that out.
With lights dimming a bad ground is usually the culprit and in your case G401 which is the ground on the left rear frame rail inboard of the tire…to check remove relay 38…one of the 4 terminals is “hot at all times” and is the control side feed of the relay…the control side ground is the BCM so it’s not that one which would be caddy corner from the feed terminal…the load side feed is terminal 30 and 87 is the ground which goes to G401…take a 12 volt incandescent test light connected to battery POSITIVE…when checking those 4 terminals one should light and that is the ground for G401…if test light dim you have bad ground or splice pack 400 needs some cleaning up…you can see G401…you can see ALL the circuits that use 401…see if any of these are applicable to what you’re seeing.
BTW, better to use an old headlight bulb to test the grounds…incandescent test lights only draw about 300 milliamps or so…this bulbs draws about 5 amps but one than draws 2 amps would work just as well…you determine the bulb to use by how much current that circuit draws.
Relay 38 clicking while braking
