Light Sensor Failure ?? reason ?HELP !!

[jaswasup]

MY 1992 le has been having some issues gobbling up these light sensors in the trunk aswell then i am driving with no tail lights only one Driverside marker on the rear lights up and yes the brake lights work

I have change about four or five of these in the ast year ( from the wreckers ) and the latest one lasted all of 5 minutes
Upon further review it appears that they all have the same internal failure
a resistor or fusible link is melting It is labeled R15-1 and on another R14-2
They are beside each other
I am curious if there is a way to pin point the specific area of the problem via these details or a way anyone has successfully bypasssed the sensor by joining wires

Also as a side note all fuses in car are good but my high beams do not work
Is there a relay or something that could be associated with this ??

Thanks

Jay

[dc_98_cam]

What you describe sounds like it might be an internal short within one of the tail light or marker light sockets ..... You should not be blowing LFS units like they were fuses ...
I have seen one instance of a shorted tail socket .... you just have to locate it ... cut it out and replace it. ....
You can remove the sensor completely, and splice the relevant wires ... probably no difficulties here. However, if do have a shorted tail light or marker light socket and you don't fix it, you will probably have future problems.
I would definitely make an effort to trace down the defective socket.
When you look at the light failure sensor, is it possible to tell if there is a numbering system on the terminals? You would need to locate a green wire going into a number 2 terminal on the LFS, and a Light green wire coming out of terminal 9 of the LFS.

[Kep]

If the sensor is the small yellow box on the side of the trunk it also keeps track of the headlights. If your bright lights aren't working then they may be the source of the fault that is destroying the sensor.

Kep

[jaswasup]

As an update before i go searching upstream

couple of things:


I put yet another LFS in and with the car off,I turned on the lights then walked to the back to see the taillights working BUT they were flickering badly so i turned off the lights before the sensor blew again ( removed until retest)

What if anything will this indicate ( perhaps narrow it down )

Question : In the summer i changed out the Main power relay for the windows and i just relooked at that post and beside that relay is a "taillight control relay"
Would this have something to do with it (it is however in a very tight spot to reach so i am hoping not )
When i changed out the power relay for the windows the continuity had been decreased therefore it failed and no windows were operational
If by chance the same has happened to the taillight control relay would this have the general effect i am dealing with Blown Sensors leading to no operating taillights (only one marker works ) again i will mention that my HIGH beams are not currently working and it may be associated ??Not sure

[dc_98_cam]

Download the Gen 3 Wiring Diagram .... see online repair manual download at top of forum page ..... In the wiring diagram section, the headlight schematic is shown on p. 104.
Are you sure that the high beam headlights are not just burned out?
Assuming that you do not have Daytime Running Lights ....

If the tail light relay or fuse were blown, your front clearance and marker lights would be out. See. p. 144 and 145 of wiring diagram.

If you want to try to find out where the problem is ...
First remove the Light Failure Sensor, and then locate a light green wire coming from terminal #9.
Follow the light green wire until you find a connector .... should be on one side or the other.... Disconnect the connector, replace the LFS and see if it acts like it is going to burn out ....
By doing this you have isolated the short circuit to one side or the other of the tail lights in the trunk. Connectors Bz1 and Ba1 are shown in location diagrams on p. 46 of the wiring diagram. Once you have found out which side of the trunk has the problem, you will probably have to cut one of the tail light wires to find out specifically which one is the problem .... It may be that you could manually hold one of the tail light sockets or wires and determine if they were unusually warm or not .... Maybe, maybe not.

[jaswasup]

next test i performed came up with these results:

I plugged in the new LFS and did not turn on the lights but had the car running in nuetral with no park brake on
When i checked the tail lights were on and only one right side rear marker was out as well the daytime running lights were not on but both front corner markers were lit up

[Kep]

Have you removed each bulb to see if the sockets and bulb bases are clean and free of corrosion? I am still suspicious that the high beam problem might be a factor.

Kep

[dc_98_cam]

DRL Relay no. 2 would control the DRL lights as well as the hi beam headlights.
The tail lights might be an independent problem.
DRL Lights will not work with the emergency brake on ...

[jaswasup]

Here is what i know :

DRL's are not functioning
High Beams do not work

And with LFS installed i get a flickering in the taillights until the LFS fails

I will post tommorrow with my findings when i pull the rear bulbs in the car and view the wires and condition of sockets

I appreciate everyones help

I pulled the relays for the DRL that i found in the schematic and with no reference to check for continuity i winged it and just looked for a weak signal but found none
Interesting how the schematic calls it a DRL relay but the fuse box lists it as a Dimer relay no2 ???

[dc_98_cam]

Not sure if you can tell, but DRL no. 2 .. however it's labeled in the fuse box should have terminals 1, which goes to a black wire, and terminal 3, which goes to a red wire .... and power the 'coil' .... meaning you should find 'continuity' between them.
With no power applied, there should be an open circuit between terminals 1 and 2, where 2 goes to a red wire with a light blue stripe .... Not sure exactly how the terminals are labeled .... just looking at the wiring diagram.
... Good idea about looking at the tail light sockets and bulbs.

[jaswasup]

results from inspection of bulbs and sockets at both tail lights

All bulbs were correct in their respective sockets 1156 /1157 etc

All sockes were clean and no wires appeared to be in any poor condition

One bulb which i expected is burnt out -R.S marker (peanut bulb )

I will replace peanut bulb

Still at a loss as to why no High Beams No DRL's and LFS blowing
I have grabbed a few LFS from the wreckers each time i go as i know what their worth and the wreckers had no idea what it is and i noticed today the White box ones are of a different part # and are a wee bit diffferent on the circuit board ??Not sure exactly why

[dc_98_cam]

Check the continuity across the relay coils of DRL Relays no. 2., no.3, and no. 4.
These relays control current to the DRL lights and also the Hi beams.
You can find relay location and relay terminal numbers on the online wiring diagram
No. 2 is next to the firewall by the battery, no. 3 and no. 4 are at the front near the radiator.
What would have caused a problem like this? Did you have some sort of catastrophic electrical short?

[jaswasup]

Originally Posted by dc_98_cam

Check the continuity across the relay coils of DRL Relays no. 2., no.3, and no. 4.
These relays control current to the DRL lights and also the Hi beams.
You can find relay location and relay terminal numbers on the online wiring diagram
No. 2 is next to the firewall by the battery, no. 3 and no. 4 are at the front near the radiator.
What would have caused a problem like this? Did you have some sort of catastrophic electrical short?

I see the relay locations in the schematic however i cant see any relay term #.s to check exact continuity on relays

I believe the No2 relay in my car is called a Dimmer relay -What would that be refering to
If i have flashing bulbs just a thought could that mean any of the taillight relays may have poor continuity such as the relay i had an issue with for the power windows back a few months
I know in the schematic it lists a tailight relay beside the main power relay that i changed out in the summer to fix up the P-windows that had very weak continuity and it is the same type of relay -Very hard to get at though
You need to have tiny motorola fingas-I have spares of these and i am going to pull it and inspect for a continuity issue-cant hurt-

[dc_98_cam]

Look on p. 26 of the wiring diagram pdf ... this shows where the terminal numbers are for the no. 2 DRL relay.
P. 27 of the pdf shows the terminal numbering for no. 3 and no. 4 DRL relays.

Can you find the relays on your car or not?
Do you have the I4 or the v6 engine?

[jaswasup]

forgive me but i must be looking at the wrong manual or ???

I do not see the diagrams your listing

Please direct me
Thanks