Late last year I decided to put LED bulbs in my reverse lights because they're brighter and I just like the look. As soon as i Got the first one in I got a "R LAMPS" on my system check screen. I figured that might happen since I hadn't put resistors in. I put the car away for the winter that same day. Come spring I take it out and along with the "R LAMPS" message I got "F LAMPS" and my right headlight motor is constantly spinning without the headlight really moving. I turn the headlights on and the left light goes up but i have no park or fog lights. I took the motor apart and replaced the three parts between the plastic gear and metal shaft, greased everything and put it back in. Now both headlights go up but the right motor is still given power after the arm has locked in. Still no park or fog lights and both "R LAMP" and "F LAMP" messages are showing up. I checked the tail lamp fuse and sure enough it's blown. I'm currently working using a Haynes manual so my schematics aren't very good and since this all seemed to start with the LEDs I went and put 3.7 ohm resistors in each reverse light circuit on the ground side (the incandescent bulbs were 3 ohms cold). The next fuse blew instantly just like the last one. I've done a search and didn't really find anything that matched. Any help is appreciated.

 

DigiTach, right?


Look at the fuse you keep replacing. I guess it's a 20 Amp fuse.
If your LEDs were the cause, your fuse should only blow when you put the car in reverse, as only then the circuit is closed for the lights to come on.


Your headlight motor might be pulling such an amount of current, though. If it doesn't shut off after reaching its end position, I think your GUIDE box, which controls headlight operation, my be shot and needs to be replaced.
Find it in the engine bay somewhere on your firewall and perhaps disconnect it for testing purposes.
IIRC, the motor tries to work against the final position, therefore pulling more current which the GUIDE box detects and then cuts the power to the motor.


Aside from having become brittle over the years, the parts you have replaced inside the motor must have been made breakable on purpose, so the motor can turn freely in case anything goes wrong, so nothing catches fire due to too much power on the wires (that's my theory, at least, looking at how the motor is built).


Back to the tail lights.
If you have a short in there somewhere, it can be anywhere from inside the socket (check your LEDs' contact surfaces and if they possibly bridge something) up into the shifter where your back up/reverse switch sits.
I don't know where the wires for the back up lights run to, but the tail light/brake light wires run up into the steering column, where the brake light override is done when your running lights are switched on.

 

It does have the digitach and you're right, it's a 20A fuse that keeps blowing. This car sits alot so years ago i got into the habbit of disconnecting the battery when it's not in use. That fuse goes as soon as the battery is connected. I'll disconnect the module and see what happens.

 

Good approach.
If you want to be clear about it being the module and not the motors, do another test WITH the box and W/O the headlight motors, then connect the motors one by one and test again after each of them.

 

I'm typing as I work so bear with me. With the module completely disconnected the fuse survives, the messages on the system check screen are gone, and my park and fog lights work the way they should. Same if the connector on the left (driver's left) is plugged back in. Both connectors plugged back into the module and the motors unplugged it's the same story. The fuse lives on, lights work, and no messages. I plugged the left motor back in. Again everthing works as it should. Plugging in the right motor blew the fuse instantly.

 

With the fuse still blown i decided to measure resistance between the two terminals on the harness side. I got OL. I also measured for voltage. Both terminals have about 4.7v

 

Don't know about resistance and will let others chime in on that.
So now you know it's got to do with your right headlight motor.
If you had an extension to connect it to the other motor's harness connector...
You COULD remove the entire assembly, move it over, connect it... and of course readjust all your front end gaps for HOURS afterwards
It would be interesting to know how much current flows from/to the headlight, but that means getting your ampmeter inline and possibly frying it if it can only take 10 Amps or so.


Obvious possible spots for cable breakage:
Connector at the headlight lense
Connector at the motor terminal, disappearing under your lock plate


Haven't seen more of this part of the harness than that yet.
Got any wiring diagrams to follow?

 

The haynes diagrams are all i have and there not very good. I actually don't think it's the motor since it only has two wires going to it and it still goes up after the fuse is blown. I might try pulling the motor and plugging it into the left side just to see if it blows the fuse. I've removed it without removing the rest of the assy three times now.

 

It's deffinately the motor. As soon as I plugged it into the left side it blew the fuse. The motor seems to be shorting to the case.

 

Wow. Time for a replacement motor, then. Or you can take it apart and check all the connections, try to fix something there.

 

I took the motor apart and found the problem. The brushes were worn, broken and out of their slot. I've been able to replace the brushes with new ones. My current problem now is getting it back together. Is there was a way to get the **** off so I can put the rotor in without the cover?

 

Not sure about that one, but I think they're pressed on. Lon should be able to tell you.