Does anyone have access to these?

I'm having three specific problems with my Nov 1991 XR4x4 wiring:

1) Interior light works fine from the passenger door but not from the drivers door.
As far as I can tell from the car itself, there is a wire from each a-post switch to a relay on the steering bracket. From there, a wire goes to the delay relay in the fuse box and on up to the light.
If I use the driver's door terminal on the relay for the passenger door switch, the light comes on as normal so the relay seems ok, and the wire from the relay to the drivers door appears to be complete and working.

2) Door-ajar display shows the tailgate is open.
The microswitch on the catch has three tails but only two are connected. The third comes to a bullet connector but I can't see a corresponding wire for it to plug into, either in the tailgate or in the main loom at the roof.

3) Boot light isn't coming on.
Not sure where this is switched or how. The lamp has red and brown cables but no power.

 

the first thing for you is to try a haynes manual! these have wiring diagrams in them!

regarding the door light this is almost always an earthing fault due to corrosion / dirt around the door open switch, try cleaning wilth a dremmel! also try grounding the wire there and see if that works.

check the microswitch and see if it is open or closed circuit normally then make it the other for a test with the 2 wires! the 3rd tail could be as the switch is a 2way switch and the connector is on the wrong way!

the boot light will need checking with a volt meter and might be related to point 2!

good luck!

 

Brendan

The Haynes manual diagrams are only for cars up to 1990. At that point Ford changed a lot of things around such as the third wire on the door microswitches, courtesy light wiring, etc.

The door switch has a good ground and I get the same result when I bypass the wire and switch completely and go directly from relay straight to ground. That's why I'm mystified because everything logical tells me it SHOULD work, but it just doesn't.

 

if that is the case is the relay ok? can you check it with a DVM?

Also check the funny little switch in the light itself - on all the time door light and off as that could be a problem! failing that you will probably end up tracing the circuit!

 

Just uploaded it for you.. 1990-1993 Sierra wiring diagram...

http://members.chello.nl/a.gruijs/Wi...a1990-1993.pdf

 

Wheely-Boy Excellent. Thank you for doing this.

Guess what I will be doing this evening?