P38A Electric stuff

oakey · Apr 11, 2020

1990 4.0 Auto
Tailgate button has not worked for ages and now trying to fix
Trying to test wires and connectors etc but does anyone have a good way of probing these tiny wee connectors in the blocks?
My probes are too big to go into the connector and not sure about sticking a screwdriver in in case it deforms the socket.
Does bare copper wire work without distorting the socket?

brianp38dse · Apr 12, 2020

I would think that will work ok, if its any help the tailgate earths through the drivers door lock a fault in the lock can stop the tailgate working.

romanrob · Apr 12, 2020

Use safety pins in the back of the connector (or the face, for that matter) - they stick out enough to grab hold of, obviously you have to be a bit careful not to short between two. Also, it's v useful to get a few lengths of wire and put a mix of male or female pins on one end (and whatever you want on the other), so that you can plug them into the connectors directly (if you have the connector undone, and especially if you need to connect to a male connector)

Grrrrrr · Apr 12, 2020

oakey said:
1990 4.0 Auto
Tailgate button has not worked for ages and now trying to fix
Trying to test wires and connectors etc but does anyone have a good way of probing these tiny wee connectors in the blocks?
My probes are too big to go into the connector and not sure about sticking a screwdriver in in case it deforms the socket.
Does bare copper wire work without distorting the socket?

I think Datatek did a write up on taking the boot button apart years ago. Can you trigger with Nanocom?

As Brian says, it grounds through the centre microswitch on the driver's door lock actuator. If it isn't rust in the switch then that's usually the failure point.

Datatek · Apr 12, 2020

Boot button not working can be one of 3 things, the micro switch in the drivers door lock seems to be the most common, after that the button micro switch fails, I have a low cost replacement for that, and finally the wires can break between the C post and the tailgate.

oakey · Apr 12, 2020

Thanks for all your replies.
New button and new drivers door lock.
New button only worked for a couple of days then failed again.
Thinking is the earth but having difficulty connecting to the connectors. I am not getting continuity to earth but as they say absence of evidence is not evidence of absence.
I will try a safety pin in the connectors thank you

Bix · Apr 12, 2020

When mine failed it turned out to be the actuator. Cleaning it and regreasing worked for a few months until it failed again. In the end I just got a newer one off of the Bay of things... I cleaned and grease that one before fitting. Been on for 2ish years, if not longer.

RangeRoller dt · Apr 12, 2020

I stripped mine. It’s chrome
(£90 to replace!

) Ive thread on it.

Youve had it apart?

If it’s the micro switches I’d go Datas route take it out of the equation.

oakey · Apr 12, 2020

Its a brand new switch and when pressed I get continuity

oakey · Apr 12, 2020

The solenoid works by hand and doesnt feel stiff

Datatek · Apr 12, 2020

oakey said:
Its a brand new switch and when pressed I get continuity

Continuity with a DVM is a bit different to passing enough amps to drive a solenoid. A test lamp is more useful

oakey · Apr 12, 2020

Good point. Does it not just send a signal to say "I want to open the tailgate" And then the computer stuff says "Ok then" and opens the tailgate?

Datatek · Apr 12, 2020

oakey said:
Good point. Does it not just send a signal to say "I want to open the tailgate" And then the computer stuff says "Ok then" and opens the tailgate?

Never looked to be honest, I know that the button earths through the door microswitch, I'll have a look in RAVE.

oakey · Apr 12, 2020

I thought the earth was at C Pillar?

oakey · Apr 12, 2020

The middle connector does look a bit corroded. Sprayed with contact cleaner and the female bit but not sure if the female bit is clean. And I am talking electrics

Datatek · Apr 12, 2020

oakey said:
I thought the earth was at C Pillar?

Look at RAVE, the BECM is not involved, the circuit is live via a fuse F15 to the actuator, then to the button and from the button to the micro switch in the drivers door lock, then via the out station to earth.

oakey · Apr 12, 2020

Aaaah thank you I hadnt realised that. I will check ta

Marshall8hp · Apr 12, 2020

Datatek said:
Look at RAVE, the BECM is not involved, the circuit is live via a fuse F15 to the actuator, then to the button and from the button to the micro switch in the drivers door lock, then via the out station to earth.

Datatek, could you substitute another earth? Would earthing locally be viable or would that interfere with the driver’s door etc?

Bix · Apr 13, 2020

oakey said:
The solenoid works by hand and doesnt feel stiff

Mine didn't, but the motor inside makes contact with the casing, so could be the connection just got weak over time. I was planning on investing further if I could revive it, but never found the time or effort to bother.

Datatek · Apr 13, 2020

Marshall8hp said:
Datatek, could you substitute another earth? Would earthing locally be viable or would that interfere with the driver’s door etc?

If you substitute another earth, it would be possible to open the boot even when the car is locked.

P38A Electric stuff

Well-Known Member

Well-Known Member

Well-Known Member

Technician, Bodgit & Scarper Ltd

Well-Known Member

Well-Known Member

Loading...

Well-Sprung Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Loading...

Well-Known Member

Similar threads