[hermanpj]

RRC people, help!

The high mount stop lamp on my 91 RRC has quit working. I have checked the fuses in the dash panel and all appear totally intact. The bulb is brand new. I opened the plastic covers that surround the connections from the wiring to the bulb carrier and the connections are not corroded - look like new.

Tried to check whether the bulb was getting current using an electrical outlet tester for house wiring. With a wrench mashing down the brake pedal i was unable to detect an current, but i also couldnt detect current when i used the tester on the righ hand tail lamp brake light, so maybe automotive current is just to weak (i know very little about electricity so thats all i tried).

the only other thing i can think of that might be relevant is that the tailgate lock actuator has been removed, leaving the circuit which powers the actuator unconnected. i dont think that could be causing a problem, but who knows?

 

[troverman]

I think where you'll find the problem is where the wiring come into the top gate from the roof of the cabin. There are two little rubber pieces which shield the wiring which comes in from the roof. There should be some pink wires in there. Also where the rear glass defroster is hooked up. Gently pull back those rubber pieces (push them into the roof) See if the wiring is intact. Mine has had this problem intermittently and just wiggling it seems to cure it for awhile. Also, make sure the connection where the bulb is seated is OK. It may look good but actually isn't. I don't think the actuator has anything to do with providing the power. By the way, the key has to be in the second position for the brake lights to come on when the pedal is pushed. Just let the car run when you test.
Should be +12V at one of the wires going to the bulb. House current is 120V AC and car current is 12V DC. Go to Wal-Mart and buy a meter, they have them for like $10. Worth your while if you own a Range Rover.

Put the black probe to a ground, make sure it is a good ground. Then with the brake pedal depressed fully with the car on probe each of the connections and you should get 12V. If you do, and the bulb is good, twist it around until it lights. If not, play with the wiring in the roof connector till it lights. Good Luck.
I can't stand that 3rd brake lamp being out.

 

[hermanpj]

that is awesome. i am on the way to walmart or pepboys to buy the meter tonight.

i checked that the electrical connections appear to be sound in the bundle of wiring inside the loadspace area behind the right hand tail lamps. i did look at the wiring coming down into the tailgate, but not as rigorously. will check it out. thanks for the advice.

 

[hermanpj]

OK so I bought a circuit tester and multimeter. I tested the wiring using each and verified that with the vehicle running, and the brake pedal pressed, a 12 volt current is passing through the circuit that powers the high mounted stop lamp. i checked the wiring in two places: at the bundle of wiring the passes form the headliner into the lift gate, and within the stop lamp assembly itself. I was able to verify current in both places, but the stop lamp is not coming on. Any other ideas?

 

[Jonesy]

Bulb?????

Just kidding....I am sure you did that! I actually had the same issue and ran a check on everything. Current running thru was fine but the wire had come off the solder on the little blue bulb holder. Take the bulb out push down on the bulb spring/seat and have a looksie at that. :buttrock:

 

[hermanpj]

Jonesy! So funny. Yeah I checked the ol bulb out, thanks! As a matter of fact i had had to replace the stop lamp assembly, and it came with a new bulb carrier (the blue plastic thing) and bulb, so i'm pretty much covered there. whats killing me is i can detect 12 volt current by putting my multimeter test leads directly on the positive and negative connectors that attach to the bulb carrier, which is as I said, brand new and the bulb is brand new. I'm at a loss. here's where my electrical knowledge is weak.

is there some way the bulb could be getting 12 volts of current but some other electrical property is preventing it from lighting? i mean, is there anything else i can test? i guess if im going to own a RRC i need to get smarter on electricity.

 

[Landy-Andy]

Bulb contacts.....

Hi,
Sound like the only thing left to check is whether the bulb contacts are aligning with the bulb socket contacts?
When the bulb is screwed into place can you ensure that all the contacts are aligning & touching together?
Also, just to be sure, use your meter leads to test the new bulb directly on your battery (Caution - take care not to let the leads touch together!)
good luck,
Andy

 

[Jonesy]

I am not sure how it works, but what about the relay? Or maybe the wiring that coordinates the rear brakes to the high mount? I dunno but have you put anything aftermarket on lately that you may have drilled a hole through a wire and thus grounded it? Sorry mate......I am tapped out too.

 

[hermanpj]

well the lugs on the bulb appear to be making perfect contact with the contacts in the bulb socket. also the bulb socket is brand new. no new additions to the electrical system that would account for changing how circuit is grounded or anything like that. the bulb itself lights just fine off of the battery. i dont suspect the relay or brake lamp switches are malfunctioning but who knows. my two remaining theories are that either there is a short somewhere in the wiring or perhaps there is too much resistance already loaded on the circuit somehow, which is preventing the bulp from receiving sufficient amperage. looks like i will need to replace wiring.