Tailgate wiring (again....)

mr_s · Mar 18, 2018

I've had a look through a load of posts, and just want to check that my reasoning is sound...

Pressing the tailgate button does nothing, it has to be opened with a handy piece of wire that the PO left for me.

My diagnostic procedure thus far:

Check that all doors lock and unlock from fob and key: Yep, all working fine
Check for continuity across the tailgate switch: Works fine, pressing the switch makes connection
Check for power at the switch wire: Yep, voltage as expected
Check operation of 'moving parts': Removed from tailgate and checked with separate power souce, all working
Check for ground: No ground

I figure my problem has to be the lack of ground. Is this picked up from the CDL switch in the drivers door? Obviously I could just permanently ground it, but that would mean the tailgate would never be locked and would permanently open, correct? Which connector/wire from the BECM provides ground for the tailgate, as I guess I could (temporarily) splice into that and run a wire to the tailgate to test it?

Cheers, Martin

Ratae · Mar 18, 2018

Which model RR?

al-one-arm · Mar 18, 2018

according to rave on a 1995 model the white wire coming from tailgate switch goes to the connector on the right tailgate lights, so i would check if the tailgate lights work, if they do then check for continuity, otherwise the wires go into r/h side rear luggage compartment into a 10 way connector

Orangebean · Mar 18, 2018

This should help you with following the gnd from the door actuator. If your CDL works from the drivers door key switch, you've just got to trace continuity from Splice 753 to the tailgate unlock switch

mr_s · Mar 18, 2018

@Ratae - I always forget the one important detail! 1997 P38 2.5DT

@al-one-arm - They are all bl**dy white, not sure why LR decided on that one.... All the tailgate lights work though

@Orangebean - Thanks for the wiring diagram and the details, I'll give that a bash next time the weather isn't too sh*te

mr_s · Mar 25, 2018

Bit of an update on this - it turns out that the drivers door key *doesn't* operate all of the locks (must have had a brain fart and thought I had tested it....), just the drivers door itself. Pressing the 'pin' on the inside of the door operates the central locking correctly.

Would this signify a problem with the CDL switch, or not given that the door pin operates the central locking correctly?

Orangebean · Mar 25, 2018

Assuming that your car is not in an alarmed state, all doors should unlock when you turn the key to unlock. I'd do a quick test on the 3 microswitches in the latch if I were you.
MartyUk has a very useful sheet on the test process
http://p38webshop.co.uk/RRdocs/P38 Door Latch Tests.pdf

mr_s · Mar 25, 2018

If the car is in an alarmed state (I assume it is, it had been locked with the fob), would all of the doors not unlock off the key? Appreciate the help, thanks!

Orangebean · Mar 25, 2018

If the car is locked with the fob and unlocked with the key it will go into an alarmed state and demand EKA code entry or fob press. In that condition only the drivers door will unlock

mr_s · Mar 25, 2018

Interesting, thanks for the info! I'll try unlocking with the fob, then locking and then unlocking with the key next time I head out - see if everything works that way!

mr_s · Mar 26, 2018

Ok, I tested and I'm back to the original post - it does lock and unlock off the key (when not set by the fob!)

Hopefully after work tomorrow I'll do some wiring tracing/testing using the info above to see what's what. I shall report back!

wammers · Mar 27, 2018

mr_s said:
Ok, I tested and I'm back to the original post - it does lock and unlock off the key (when not set by the fob!)

Hopefully after work tomorrow I'll do some wiring tracing/testing using the info above to see what's what. I shall report back!

Look at the arm and push/pull wire connecting key lock part to the latch. It may need adjustment. Or may have come adrift.

mr_s · Mar 30, 2018

Found the problem - traced the wiring and connectors, as shown in Rave (and as per the diagram above, cheers again!). Turned out to be a severely corroded connector block in the front d/s door jamb - just where it enters the main body from the door.

Got lucky with it, 3 other connections crumbled as I removed it - all wired back up correctly and the tailgate works perfectly.

Thanks again for the help chaps and/or chapesses

brianp38dse · Mar 30, 2018

That looks well crusty and a couple of broken pins to boot, did you just cut the connector of and hard wire it in.
these came up in a thread in general land rover section and look just the ticket for this sort of job
https://www.ebay.co.uk/itm/New-50pcs-Various-Size-Solder-Seal-Heat-Shrink-Butt-Wire-Connector-Terminals-UK/122726975243?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

mr_s · Mar 30, 2018

Yep, connector gone and hard-wired in. Used very similar things to those you've shown there (similar crimp connectors with heatshrink tubing - some I had left over from fitting o2 sensors to the Chevy a couple of years ago!)

Now everything electrical works, except the rear wiper and I can live without that....!

Tailgate wiring (again....)

mr_s

Member

Ratae

Well-Known Member

al-one-arm

Well-Known Member

Orangebean

Active Member

mr_s

Member

mr_s

Member

Orangebean

Active Member

mr_s

Member

Orangebean

Active Member

mr_s

Member

mr_s

Member

wammers

No longer with us, RIP

mr_s

Member

brianp38dse

Well-Known Member

mr_s

Member

Similar threads