4x4 blinking...

[Deiz29]

Ok I've searched around for a few wks since I got my 1999 3.0 ranger xlt

My issues haven't been resolved by changing the speed sensors or the vacuum hoses and I also noticed that my dome light doesn't work either. All fuses are fine that I've check #13 and 25 for the Gem. They blink 6 times high and low like most but I can't seem to figure it out. The shift motor is new but it will not engage when I switch the button. (I was under car and listened nothing) I haven't tested power to the wires yet since my green lee is at my parents but what should I check for and where? Also how do I tell if my gem is faulty? Everything else works. All the lights on dash speedo radio etc. only thing I've noticed that doesn't work is the dome light and my 4x4 lights are blinking. I had code c1145 for the speed sensor they looked brand new but I took them out and cleaned them anyway. No change. The hoses on the front wheels were both broken off so I cut away the bad and reattached them. Still nothing... So where should i start?

 

[RonD]

Welcome to TRS

Good page to book mark here: http://www.therangerstation.com/tech_library/index.shtml

And read about 1995 and up Ranger 4WD issues: http://www.therangerstation.com/tech_library/4wd_control_module_95-up.html

In 1999 the GEM does control the 4WD system but there is also a Relay Box that controls what direction the shift motor turns and these have been known to fail.

The flashing 4WD lights often means the GEM tried to shift transfer case, but motor didn't move, which is why you check the fuses first, if they are good then Relay Box is next.

Go to this thread: http://www.therangerstation.com/forums/showthread.php?t=162915

I posted the 4WD wiring diagram there, 1998/99 are exactly the same

 

[Deiz29]

Thanks for the info I am going to look into my 4wd cube when it gets light out. I'm gonna shoot to the junk yard today anyway so if I find one I'll see if swapping it helps. So from what I've read on those links and pdf's is basically there are only the two fuses one in dash one in engine bay? I checked those both are good. No noise at all when I turn the 4x4 switch. All wires seem to be in tact and car was basically unmolested when I got it. Now my other question is...

Are there sensors on both the front and rear axles? I saw one for the rear above the diff? I didn't notice any in the front but it was getting dark when I looked. I read someone had an issue with those as well? Thanks in advance and thanks again for the diagrams wish I was more electronicly inclined but my buddy may be able to help me out.

 

[RonD]

The shift motor on the transfer case has a "wheel" inside with metal contact points, this wheel turns when the motor does, this turning opens and closes the 4 contact points, and this is how the GEM can tell what position the transfer case has been shifted to.

If GEM closes a Shift Relay(either one) it will expect the motor to get power and turn the wheel, this will open or close a contact because of that movement.
If motor/wheel doesn't turn, then GEM will flash the 4WD lights to indicate a problem.

Yes, could be the 20amp fuse for the shift motor, or could be the CW(clockwise) or CCW relay isn't working in the Shift control Relay box.

The speed sensors could cause an issue with 4WD Low, but 2WD or 4WD high can be used or shifted to at any reasonable speed.
Front "speed" sensors are for 4W ABS(anti-lock brakes), so not on all models, and not part of 4WD system, if you have 4WABS then each front wheel would have that sensor in the Hub.
Rear axle sensor is used for speedometer and also the ABS

 

[Deiz29]

Ok I have sensors on both wheels. I've cleaned the driver side but it did nothing they're both new so I wouldn't thing that's the issue but I'm going to do the pass side now...

Is there any sensors in the axles front or rear? I thought I remembered someone saying that the rear hall sensor? Was the culprit to his 4x4 not working...
I was at the yard earlier and grabbed a few relays and also a relay behind the gem but mine doesn't have that?
The shift motor is new do I take that off and see if anything is happening?

Also which relay controls the 4x4 I've seen the fuse in the distribution block relay under hood was fine so was 13 under hood.

My dome light doesn't work as well which is why I think it's more electrical somewhere?

So should I take the new motor off and check even tho I don't hear any sound when it gets engaged and I'm under it with someone switching it? Or should I just disconnect the plug and check for power? Which wires should have power? Also the ground wire is attached into the t case so how do I go about disconnecting that?

 

[Deiz29]

Ok so I checked the motor to the t case it's getting power and ground is good. Nothing changed when I hit the 4x4 switch inside the car. Low or high nothing. So is my switch bad? I replaced it w one from the yard but no change....

 

[RonD]

How did you test for power at the shift motor?

Only way is use the dash buttons and then motor will get power, otherwise there is no power at that motor.

And it is a DC motor that has to turn in two directions, clockwise and counter clockwise, so it has no "ground" wire to test.
12volt and "Ground" are reversed depending on which way the motor needs to turn.

There are usually 6 or 7 wires in that harness, the two that separate and go to the motor are the ones that should have power/ground when 4WD switch is pressed/moved

 

[Deiz29]

Sorry for the late response I was away. Anyway I had my buddy come w his snap on and these are the codes I pulled../


B1313
B1371
P1824
P1820
P1828
B1352
B1318


Bad gem?

 

[RonD]

"B" codes are Body codes
"P" codes are Power train codes

first number
0 = Generic
1 = Enhanced (manufacturer specific)

P1820 Transfer Case LO/HI Shift Relay Circuit Open/Short To Ground
P1824 4-Wheel Drive Clutch Relay Open/Short To Ground
P1828 Transfer Case HI/LO Shift Relay Coil Circuit Open/Short to Ground

Reads like wires are disconnected, or there is no power

B1313 Battery Saver Relay Coil Circuit Failure
B1318 Battery Voltage Low
B1352 Key IN chime circuit open
B1371 Illuminated Entry Relay Circuit Failure

Since engine starts and runs battery voltage is fine but...........B1318 says power was not getting to some circuits at some time in the past, B1313 could mean fuse #26, 10amp has blown, check that

Yes, all these "P and B" codes could be caused by failing GEM or connector on GEM

I believe in '99 Ranger's access to GEM is by removing the radio unit, check the connectors on GEM first, make sure they were tight and then remove and check for corrosion.

 

[Deiz29]

Thanks Ron. Fuse 26 has checked out fine. I'm going to the yard today to get a new gem intook a pic of mine when I pulled it out so I get the right one. Does the gem have to be from a truck w similar options? I found mine is a flex fuel version of the 3.0... also I have no power windows or locks. Or is the number on the gem all that matters? Mine is

xl5t-14b205-ec


I removed the gem and relay behind it both were clean inside no rust no bad wires no bad solder joints either... so I'm gonna try and swap one from
The yard today if I can find one w those numbers I have and see if that changes anything




Edit - went to the yard picked up two new gems. One was the same so I swapped it... no change than I remember what Ron said about the fuse... my friend said he checked the fuse I went back and noticed there wasn't one! Plugged one in and its all working now! Thanks again ron

 

[RonD]

Good work

So old GEM is OK?
There was just no fuse the whole time?

 

[Deiz29]

Not sure if my old gem was ok i swapped one from the yard than no change. Than I remembered what u said about fuse 26 I figured I would check and sure enuff nothing was there. Had a spare 7.5 put it in and the dome light popped on. Than I checked 4 high and it worked haven't driven it yet been rainy here and truck isn't insured. But if anyone needs a gem I have two extra. But thanks again ron u saved me hours of headaches