Bonnet - hood - trunk light is not working - Not So Simple
05-07-2018, 02:19 PM
#16
Instructor
The light in the luggage compartment is not controlled directly by the switch in the latch. The front latch switch is logic to the Alarm Control Unit. The alarm control unit turns on the "inside light" circuit by applying a ground to the luggage compartment light and the inside lights (in the 'automatic') position. The ground for the switch on the luggage compartment lock is on the passenger wheel housing right.[/CORRECTION]
05-07-2018, 08:28 PM
#17
Check point-to-point connectivity on the wires running to the frunk light.
I found chafed wires which caused a non-working immobilizer light in the clock, and of course prevented successful programming of a new key fob.
Problem solved for me with rectifying the chafed wire.
I found chafed wires which caused a non-working immobilizer light in the clock, and of course prevented successful programming of a new key fob.
Problem solved for me with rectifying the chafed wire.
08-12-2018, 10:23 PM
#18
Instructor
Correction: There is power to the positive side of the light, but The ground seems to be the problem.
I tested the ground and noticed that power goes down to 0.5V when using the voltiertet instead of the bulb. As soon as I move the negative lead of the voltimeter to te strut bar, it shows 12V again.
I cleaned the connector but that did not help. Unfortunately, the wires disappear into a harness that goes into the firewall and are very hard to trace without cutting up the harness. Where does the ground go? And if that isn’t the culprit, what’s the easiest way to find out of the ground wire is chafed somewhere? Any common place that would happen?
thanks!
I tested the ground and noticed that power goes down to 0.5V when using the voltiertet instead of the bulb. As soon as I move the negative lead of the voltimeter to te strut bar, it shows 12V again.
I cleaned the connector but that did not help. Unfortunately, the wires disappear into a harness that goes into the firewall and are very hard to trace without cutting up the harness. Where does the ground go? And if that isn’t the culprit, what’s the easiest way to find out of the ground wire is chafed somewhere? Any common place that would happen?
thanks!
06-10-2021, 12:20 AM
#20
Correction: There is power to the positive side of the light, but The ground seems to be the problem.
I tested the ground and noticed that power goes down to 0.5V when using the voltiertet instead of the bulb. As soon as I move the negative lead of the voltimeter to te strut bar, it shows 12V again.
I cleaned the connector but that did not help. Unfortunately, the wires disappear into a harness that goes into the firewall and are very hard to trace without cutting up the harness. Where does the ground go? And if that isn’t the culprit, what’s the easiest way to find out of the ground wire is chafed somewhere? Any common place that would happen?
I tested the ground and noticed that power goes down to 0.5V when using the voltiertet instead of the bulb. As soon as I move the negative lead of the voltimeter to te strut bar, it shows 12V again.
I cleaned the connector but that did not help. Unfortunately, the wires disappear into a harness that goes into the firewall and are very hard to trace without cutting up the harness. Where does the ground go? And if that isn’t the culprit, what’s the easiest way to find out of the ground wire is chafed somewhere? Any common place that would happen?
Situation: Key on. Interior lights and bell triggered (as designed) when frunk opens, but NO frunk light
Done: cleaned micro switch (simple spray)
Done: cleaned frunk light connection (simple spray + a little scratching)
Done: tested frunk light connection (at connecting wires). No voltage. (while frunk open)
Done: jumped from #11 Fuse to Negative on frunk light, light illuminates, so ground is good. (while frunk open)
I read above to check points after it comes out of hood, which makes perfect sense, but as Alfa40 pointed out, those wires goes into a taped harness, behind instrument panel, etc.
Are there any other “known” possible chaff points folks have seen or is there any other “low hanging fruit” that you can think of?
It stopped working at the same time the car had a ton of work done to the engine / transmission (dropped engine, etc), but nothing on the frunk end (and, the rear deck light does work as designed).
All other known electrical works fine. (…and I do “count my blessings” for that!)
Many thanks, Edward
.
06-10-2021, 01:33 PM
#21
My situation is similar to Alfa40’s, but I have a good ground, but no power/hot. I have DM’ed him to see if he had success (in 2018).
Situation: Key on. Interior lights and bell triggered (as designed) when frunk opens, but NO frunk light
Done: cleaned micro switch (simple spray)
Done: cleaned frunk light connection (simple spray + a little scratching)
Done: tested frunk light connection (at connecting wires). No voltage. (while frunk open)
Done: jumped from #11 Fuse to Negative on frunk light, light illuminates, so ground is good. (while frunk open)
I read above to check points after it comes out of hood, which makes perfect sense, but as Alfa40 pointed out, those wires goes into a taped harness, behind instrument panel, etc.
Are there any other “known” possible chaff points folks have seen or is there any other “low hanging fruit” that you can think of?
It stopped working at the same time the car had a ton of work done to the engine / transmission (dropped engine, etc), but nothing on the frunk end (and, the rear deck light does work as designed).
All other known electrical works fine. (…and I do “count my blessings” for that!)
Many thanks, Edward
.
Situation: Key on. Interior lights and bell triggered (as designed) when frunk opens, but NO frunk light
Done: cleaned micro switch (simple spray)
Done: cleaned frunk light connection (simple spray + a little scratching)
Done: tested frunk light connection (at connecting wires). No voltage. (while frunk open)
Done: jumped from #11 Fuse to Negative on frunk light, light illuminates, so ground is good. (while frunk open)
I read above to check points after it comes out of hood, which makes perfect sense, but as Alfa40 pointed out, those wires goes into a taped harness, behind instrument panel, etc.
Are there any other “known” possible chaff points folks have seen or is there any other “low hanging fruit” that you can think of?
It stopped working at the same time the car had a ton of work done to the engine / transmission (dropped engine, etc), but nothing on the frunk end (and, the rear deck light does work as designed).
All other known electrical works fine. (…and I do “count my blessings” for that!)
Many thanks, Edward
.
So, duh, that is when I figured out that when the wires “leave the hood,” it is via a connector that connects it to the rest of the wiring harness. That connection is inside the hood Left/drivers side).
The hot (red) connection, for the frunk light was flakey. I sprayed and scratched it up and am now good to go.
I just jiggled the red line on both side of the connector…and “there was light”…so I just cleaned the connection and am good to go!
06-17-2021, 01:37 AM
#22
Instructor
Glad you found your culprit. In my case it turned out to be corroded contacts that held the bulb in place, which saved me from having to search for those chafed spots.
