Door Ajar light (But it's NOT the switch)

ibedoughboy · #1 09-22-2012, 09:50 PM

So I have an electrical gremlin for sure. I have a 2000 Supercab 4x4 3.0 Auto and have had a good portion of common problems known to the Ranger in the year and a half that I've owned it.

So the door ajar light is on as well as the dome light. I narrowed it down to the pass door and oiled up the switch. That didn't work and I pulled the latch out of the door and pulled the switch out of the latch. Using an Ohm meter the switch is opening and closing when I push the plunger...so it seems to be an electrical problem and not the switch. I checked for broken wires and could not find any.
Next, I pulled the radio bezel and unpluged the top plug on the GEM to check for continuity across the power wire of the switch (Gray/ Red). I am seeing an ohm reading across multiple wires in the GEM plug when connected to the gray/rd door harness. I don't have a pin-out for the plug so I don't know what the wires went to that I was getting readings from. That seemed suspicious so I unplugged the (working) drivers plug and did the same check on it and, as expected, I only see an ohm reading across the yellow/blk wire b/n the door harness and the GEM plug...no other wires.
So my next thought was that there's a grounding issue with the pass door harness so I cut the ground wire for the switch and directly jumpered it to a clean body ground. Still seeing the same ohm reading across multiple wires in the GEM plug. I haven't done anything with the signal wire yet.

I don't know what to check next, I hate tracking down electrical problems and any help would be appreciated. Pics are attached of the GEM and the plug I'm talking about. I hate this truck and it's going away as soon as I get a couple things fixed.

Thanks

02RangerFX4 · #2 09-22-2012, 10:05 PM

Why do you hate the truck? And do you have a double cab? I'm almost 100% sure those have door ajar switches too.

ibedoughboy · #3 09-23-2012, 07:19 AM

I hate the thing b/c every time I fix one thing something else immediately goes wrong and in Ford's infinite design wisdom, nothing is ever easy to fix. I've done the oil pan (drop most of the front suspension, unbolt transmission, etc), timing cover gasket (running water passages through a timing cover is not a good design), frame shackles and beefed up frame there, now door ajar, A/C compressor, idler squeal, and door ajar light...and I'm sure I'm forgetting something. It drives well, is comfortable, and looks nice, but I just can't stand it any more.

Thanks, I will check the back doors today to see if there are sensors back there.

I forgot to mention in the original post, the dome light is on no matter the switch position (and the dimmer switch is not on), and there is no power to the pass door switch harness where the working driver door harness shows ~10V with key on.

02RangerFX4 · #4 09-23-2012, 07:58 AM

Well that's a shame. We own 5 fords and none of em give us trouble.

CitySlick · #5 09-23-2012, 08:02 AM

Quote:

Originally Posted by ibedoughboy

I hate the thing b/c every time I fix one thing something else immediately goes wrong and in Ford's infinite design wisdom, nothing is ever easy to fix. I've done the oil pan (drop most of the front suspension, unbolt transmission, etc), timing cover gasket (running water passages through a timing cover is not a good design), frame shackles and beefed up frame there, now door ajar, A/C compressor, idler squeal, and door ajar light...and I'm sure I'm forgetting something. It drives well, is comfortable, and looks nice, but I just can't stand it any more.

Thanks, I will check the back doors today to see if there are sensors back there.

I forgot to mention in the original post, the dome light is on no matter the switch position (and the dimmer switch is not on), and there is no power to the pass door switch harness where the working driver door harness shows ~10V with key on.

thats what happens when a 12 year old vehicle wasnt taken care of properly.

FireRanger · #6 09-23-2012, 08:41 AM

You did check to make sure dimmer knob isn't turned all the way up to manually turn the dome light on, right?

Rangerman49 · #7 09-23-2012, 09:00 AM

I think your going to have to bite the the bullet and get a wiring diagram or your just going to be chasing your tail and get more frustrated. Alldata online is a great source.
One place you might look for a problem, if you haven't already is the area where the wiring passes to the door. You need to pull back the boot and look for chafing of the wires.

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Quote:

Originally Posted by FireRanger

You did check to make sure dimmer knob isn't turned all the way up to manually turn the dome light on, right?

Good call but he's got the "Door Ajar" light too!

ibedoughboy · #8 09-23-2012, 03:53 PM

yea, I'm guessing the PO didn't take too much care in maintaining it. I love my new Focus, so I have nothing against FORD...just this one has been a pain. The interior is in nice shape at least and it only has 78000 miles. I bought it wrecked with light front damage and the damage from the wreck was a piece of cake to fix, it's all the maintenance crap that has been a nightmare...plus it is a bit crusty underneath. Dad has a body shop and we fixed and painted it and it looks great now.

On a good note, I found the problem with the door ajar light; it was the signal wire for the pass door sensor. It was broken somewhere but I couldn't track it down in the door or where it went through the boot or under the dash. I found the wire in the GEM plug and ended up cutting it and running my ohm meter across the sensor directly to the wire in the plug. It no longer was cross-talking with the other wires in the plug and once that checked out I ran a new wire from the plug, under the dash and out the door to the sensor. I'm a mechanical engineer, not an electrical engineer, so this kind of stuff is not my forte. While I had all four door panels off and saw that the sensors in the back doors were all rusty and nasty, I just cut their wires and twisted them together to take them out of the circuit b/c I know they would never work right. Ajar light and dome light working perfect now.

That just leaves the ABS light on the dash now, code for LF speed sensor. Haven't decided if I'm going to bother with it or not. So, just waiting for the next thing to crop up.

FireRanger · #9 09-23-2012, 04:03 PM

Quote:

Originally Posted by Rangerman49

Good call but he's got the "Door Ajar" light too!

Oh. Duh.

Rhodyguy · #10 09-23-2012, 04:10 PM

glad you found it, and , buy the way, nice looking truck

rangerdrvr · #11 11-20-2012, 02:07 PM

Hi I own a 2000 Ford Ranger 4.0L 4WD supercab. I also had the same problem and it was not the switch. After reading your thread and looking and the pics you posted I was able to go right in and cut the correct wire and it instantly fixed the problem. I just wanted to say thanks for the detailed thread.

fire41316 · #12 11-20-2012, 03:20 PM

When that happend to me all i did was spray the handle and the latch with some lube and iy instantly went away lol

Rangerdanger4c · #13 11-23-2012, 02:11 PM

My truck occassionally has the same problem.. I just usually pull out the fuse and put it back in and by then it acts normal.. seems to work for me

etmjones199 · #14 01-30-2016, 09:33 AM

Hey everyone, wanted to thank the OP for the detailed pictures, this was the only place I could find the help I needed. Battled this same exact problem for several days and finally got it squared away. Thanks again!