Skip to main content ↑ ↓
Topic: step on brake and front marker lights come on! **SOLVED** (Read 12550 times) previous topic - next topic

step on brake and front marker lights come on! **SOLVED**

Reply #15 –
Have you made certain that all the rear bulbs are correct? I remember a couple occasions where I had a similar concern on other vehicles, and found a 3156 in place of a 3157 and another where I found somebody had literally jammed an 1156 in place of an 1157 (hard to do).  Without crawling through the EVTM, that's all I've got.

step on brake and front marker lights come on! **SOLVED**

Reply #16 –
just curious as to how a mistake on a 3156 and 3157 would cause a back circuit ??????

1156 and and 1157 YES !!!
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

step on brake and front marker lights come on! **SOLVED**

Reply #17 –
You'll have to forgive me, Tom, but it's been over 12 years since the last time I dealt with an incorrect bulb backfeed, my memory is a little foggy that far back.  People don't seem to be that inept these days.  One was an early 90's Crown Vic, and the other was a Saturn L.  Back in 00 or 01.

step on brake and front marker lights come on! **SOLVED**

Reply #18 –
the rear has never had any bulbs changed.

i did purchase about a half dozen 1156 & 57 bulbs at autozone for troubleshooting plus spares.
I did swap out the 4 rear turn 1157's with no change.
my sockets are round on the rear, not flat blade type.  I did notice (for the first time ever!!) that my rear sockets are hard plastic on the 20th, not those soft rubbery ones like on my 87LS.  on those soft plastic sockets, over time, you can actually put an 1157 in backwards if your not carefu..... that will cause you some problems for sure.  ITs almost like some improvement was made to tail lamp sockets during 87 sometime.

i still have no clue how stepping on the brake can cause the instrument cluster relay to power off and ultimatly power on the inner front lamps on either side of the grille.

i spent a couple hours looking at the shop manual digging into the full digital cluster wiring in various chapters and its my belief this harness is unique to the point that the wiring diagrams are not really exact.  this isnt the first time ive ran across not being completly clear on something having to do with a full digital star wars cluster.

step on brake and front marker lights come on! **SOLVED**

Reply #19 –
Quote from: jcassity;411647
i still have no clue how stepping on the brake can cause the instrument cluster relay to power off and ultimatly power on the inner front lamps on either side of the grille.
The problem is, stepping on the brake is "energizing" the instrument cluster relay. This switches control of the LCD brightness to the dimmer pot in the headlight switch. Since the HL switch is off there is no power to the dimmer pot. The LCD's go off.
When the relay is de-energized, the LCD's are on full bright.
Stepping on the brake is turning on exterior lights, parking lights, running lights or whatever you want to call them.
The exterior lights circuit energizes the instrument cluster illumination relay.

step on brake and front marker lights come on! **SOLVED**

Reply #20 –
as of my left side instrument cluster going dark that i posted earlier, late march 2013, i finally felt comfortable pullling the cluster to replace bulbs.

also replaced the radio bulb,

no further symptoms to date with this odd problem.

root cause here was apperantly cluster related and my car being full digital cluster, i still have no idea how or why this happened.
I simply had to wait for whatever it was to finish breaking itself.

im my opinion , this issue is gone.

I have always had uneven illumination, not it looks just like the sales brousure , nice and bright and all purdy!!!

softtouch~ also my old problem is gone with AM stations getting alternator noise.  I have this adaptor on my rear window to hold a sort antenna like back in the day when all these cars had a car booster for thier cell phones.  well i guess the shop that did the work intercepted some how my car antenna into a "Y" such that the adaptor was plugged into my radio.  That coupled with the fact the radio was not cliped into the horizontal mount to get a good chassis ground helped as well.  I deleted the extra antenna connection and now i get nice clean AM band as well as much more FM stations than before.

step on brake and front marker lights come on! **SOLVED**

Reply #22 –
well,, its how i stay informed,, so im not one of the "low information voters"

FM offers very little talk radio in my region unless im on a road trip which is fairly often

step on brake and front marker lights come on! **SOLVED**

Reply #23 –
If I wanted to hear endless talking on the radio, I'd go home and listen to my wife.  She doesn't EVER stop talking, I'm still trying to figure out when she has time to breathe.

step on brake and front marker lights come on! **SOLVED**

Reply #24 –
yes,, but,
new bulbs curing my original problem?
crazy isnt it?
 

step on brake and front marker lights come on! **SOLVED**

Reply #25 –
without a proper detailed diagram of the cluster, I couldn't say, however, I suspect a backfeed of some sort, maybe on the ground side.  It would be something unrelated that only surfaced because of the cluster lights.  That's my best guess.