"Ser4wd" and "RR" flashing.....

[flattire]

Lockers haven't worked for a couple of years now. I've tried magnet cleaning, inspected smart bar connector, replaced trans case position sensor, checked grounds and connectors. Met with Retired BLM Rig and his scanner(thank you) to try to pull code(s) but not able to access any.

Lockers will lock but when driven 50-100 yards they unlock . While driving on freeway the SERV4WD and "RR" locker lights will cycle on and off every 40 miles or so.

Finally went to dealer Wednesday for diagnostic and passenger side air bag recall. Got a call this afternoon from service writer. Seems they have been back and forth with the factory for assistance and this is still in process.

Stayed tuned for further info!!!

[waldo]

When the rear locker light kept flashing on my 07 it ended up being a bad sensor. Too bad it's part of the coil and they had to pull and crack the diff to replace it.

[trk4sale]

Time to hardwire the lockers?

[flattire]

Depending on what they find it might be the solution. Probably should have done it earlier.

For some reason I never really thought about that. Already spent $150.00 for diagnostic . That would have done the job.

Something is wrong with a system that dealer can't fix and needs factory help.

[OffroadTreks]

When was the last time you serviced the differentials?

[coder]

I have had the same issue in December based on research/feedback it happens when the rear axle heats up about 135-140 degrees then the locker actuator throws a code but still actually works, the fix would be to replace the actuator.

On my truck I changed the gear oil, cleaned the connector real good and put in a new rear speed sensor and so far I drive it everyday to work and took one long trip of 150+ miles and no flashing light but time will tell...

[flattire]

Did diff service maybe in last year. Cleaned magnets. Don't have a lot of mileage 67K for a 2005. Does mainly towing for my travel trailer (about 5500+ pounds).

Measured diff temp during last tow. Something around 135 I think. 65 MPH and up and down grades. About the same as unloaded test I did a while back.

Noon here and no call from dealer yet.

[Retired BLM Rig]

When you serviced the fluid and cleaned the magnet, did you check/adjust the magnet sensor air gap using steps 24-26? I guess really this measurement shouldn't change once it's been set at the factory unless it's disassembled for repairs. I would favor being on the tight side of the +- tolerance. I wonder if it's possible for the magnet to lose strength over time and with heat/expansion for it to be on the edge of tripping the sensor and cause a flashing light?

[flattire]

Didn't adjust sensor. It looked to be a "reasonable" distance. Not some big gap and not real close. .21" ....will keep that in mind.

Dealer called late Friday and says "they think they are close to issue" will continue Monday. I think I may just get truck back before they do further work and see if I can cut charge in half . All I really care about now is if the lockers can work. If so will be looking into hard wire.

I expected this to be an easy job. Hook up scanner, find code, give me an estimate to fix. Bet they are not too happy either with this.

[Retired BLM Rig]

If you're thinking about hardwiring, I think this is a connector you could use so that you don't have to cut into your factory harness. http://www.ebay.com/itm/Namz-NM-33472-0 ... sL&vxp=mtr I'm not 100% sure but I think it will work. One of my connectors has a broken lock tab and I was going to order it to see if it would work. It's a lot cheaper than the $25-35 that the dealer wants.

[w2dodge]

i was lucky..when this happened to me...i was covered under warranty..replaced acturator,plug...so far no issues..

[flattire]

Monday 6 P.M. update: Dealer calls about noon . Says truck needs rear actuator....About $2500. ( not sure if that is parts and labor).....and if that doesn't fix it then needs a "smart bar" at $1852. Again , not sure if that is part and labor. I say forget it. Truck still needs to "Put things back on" so not ready and will call later.

Another call at 5P.M. Truck ready. Will be an additional charge for oil for diff. $95. I say I never authorized that and he deletes charge.

Never did find out what the "code" or scan tool said. Don't think they really knew what to do. I would have thought a dealer scan tool would have been able to test lockers without pulling diff cover.

Now back to detailing and will see about hardwire next. They had truck from Wednesday noon until Monday evening but it is back home now.

[Pit Slave]

A 2005 smartbar should only be about $250. I rebuild them if it's the pin corrosion issue and can replace the contacts in the harness plug. I am still in the process of getting things together for the locker bypass sets. The easiest thing to do in the meantime is hard wire them.

Yeah, I smoked 'em, sometimes you just gotta #sendit

[waldo]

Seems like a lot of $$. I paid around $950 to have the rear changed in the 07, but that was some time ago. I doubt if the actuator itself is bad, but the sensor that is attached to it. Don't know why they designed it that way.

BTW, I had an 05 and they never could fix that issue. They worked on it on and off for two years before they pretty much gave up and cut me a deal on the 07. I couldn't really Lemon Law it because I worked for them, but they made some payments and gave me more $$ off on the new one. That truck was sold out of state and became some other dealers problem. So, I've owned three brand new ones to date. I still have the 07 and really like that one.

[flattire]

Pit: I remember seeing the smart bar (for 05 ) for about that price some time ago. I inspected the pins a while ago and they all looked fine.
Are you making 3rd gen bypass ?

Waldo: I bought mine brand new so I didn't get your old one. Couldn't fix it then and still can't fix it.

[Retired BLM Rig]

Thinking about your locker problem, I came across this diagnostic info that may help narrow down which component you need to deal with:

1. Check the voltage of the Rear lock detection sense circuit (Yellow/Tan wire). It should go from about 2.5 volts when not locked to about 1.5 volts when locked. If not, check for 5 volts when unplugged and 0 volts when the two wires are jumped together.

2. If the lock detection switch is working OK, the scan tool should indicate the same voltage. If not, the Final Drive Control Module (FDCM) is faulty.

I would test the Yellow/Tan wire when everything is normal on your truck and then test it again when lights start flashing to see if something changes in the reading you get.

[coder]

Monday 6 P.M. update: Dealer calls about noon . Says truck needs rear actuator....About $2500. ( not sure if that is parts and labor).....and if that doesn't fix it then needs a "smart bar" at $1852. Again , not sure if that is part and labor. I say forget it. Truck still needs to "Put things back on" so not ready and will call later.

Another call at 5P.M. Truck ready. Will be an additional charge for oil for diff. $95. I say I never authorized that and he deletes charge.

Never did find out what the "code" or scan tool said. Don't think they really knew what to do. I would have thought a dealer scan tool would have been able to test lockers without pulling diff cover.

Now back to detailing and will see about hardwire next. They had truck from Wednesday noon until Monday evening but it is back home now.

Not sure they year of your truck is but for a 06-09 the actuator can be had for about $350 online and a differential shop can pull the carrier and install it for $300-$400 when I checked into a the beginning of the year.

[flattire]

Haven't done much to the truck recently. Started doing detailing after it came back from dealer. 110 degrees hot spell and was getting "sick" from polish/wax. Went back to read label warnings where says not to breathe fumes. Put that aside and started working on travel trailer suspension upgrade and now needs new brakes. Waiting on parts. Lockers at back of list for a while.

BLM: That's the kind of info I thought the dealer might provide! I would have been happy just for them to verify if lockers CAN lock (which I think they do). Just don't stay locked. Service writer claimed their scan tool couldn't test that and needed to open up diff to find out. It was a waste of time/money . Will be looking at things after other chores are done.

What is the FDCM and where is it? Cost?

CODER: Truck is an 2005. Might be a reasonable price if those numbers are correct. If I find lockers are working and I just need to hardwire might go that way and be done with this mess.

Thanks for update info.

[Pit Slave]

Pit: I remember seeing the smart bar (for 05 ) for about that price some time ago. I inspected the pins a while ago and they all looked fine.
Are you making 3rd gen bypass ?

Waldo: I bought mine brand new so I didn't get your old one. Couldn't fix it then and still can't fix it.

I am now in the process of making them.

Yeah, I smoked 'em, sometimes you just gotta #sendit

[Retired BLM Rig]

What is the FDCM and where is it? Cost?

The FDCM is the smart bar.

To follow up on my previous post on this page:

If you're thinking about hardwiring, I think this is a connector you could use so that you don't have to cut into your factory harness. http://www.ebay.com/itm/Namz-NM-33472-0 ... sL&vxp=mtr I'm not 100% sure but I think it will work. One of my connectors has a broken lock tab and I was going to order it to see if it would work. It's a lot cheaper than the $25-35 that the dealer wants.

I did order this connector and installed it on my truck, due to the broken locking tab. It fit perfect, however it didn't come with any terminals, but I didn't need them since I was only interested it replacing the connector housing. It took a little work to figure out how to remove the terminals from the old housing without damage, but I finally got it. It's funny, the Ebay ad says it fits a Harley Davidson handlebar harness. Maybe I should tell them it also fits a PW locker actuator.

Anyhow if you wanted to hardwire your lockers using O.E. style connectors, you would need two of these (which include the terminals), a pack of these for sealing the two unused terminal cavities and this tool to crimp the terminals to the wires. And then wire it like this:

Image courtesy of someone else's hard work from DT.

Connect your positive and negative as shown. (courtesy Four Wheeler)

But it looks like Pit Slave might have another option for you as well.

[Retired BLM Rig]

Are you making 3rd gen bypass ?

I am now in the process of making them.

Awesome!!!
Prototype time, as the patiently waits.

[trk4sale]

Probably better to use low power wires from the switches to relays, then bigger wire from the relays to the lockers.
The switches should be powered by a source that only comes on with the ignition and you should have a way of cutting power to the relays(eg: pulling a fuse) to avoid activating the lockers if you hit a switch accidentally.
I insert my locker relay fuse as I am airing down and pull it when airing up.

[flattire]

FDCM = SMART BAR. I was thinking I had read something like that at some point but didn't remember when or where.

[nts007]

While I didn't worry about cutting the harness to use factory connectors, I did go straight from batt to switches to lockers. With these switches no much chance of accidental switching them.

Needs a 30 amp fuse and don't leave them locked with the truck off for a couple days. I wanted my lockers to stay locked in case I stalled the truck or something stupid happened and killed the engine. Lockers just need the 12v +/- and bang they go

[Retired BLM Rig]

If you wanted to get tricky, you could gut your factory switch and reuse the faceplate and knob and then mount a rotary switch from a small appliance, like a space heater, to the back of the faceplate and add a couple of indicator LEDs. It just depends on how factory you want it to look.

You could probably find a cheap space heater at a local thrift store to cannibalize for a switch.

Instead of "OFF, FAN, HEATER" it would be "UNLOCK, RR. LOCK, FR & RR LOCK". These switches are made to handle high amperage (1500 watts) without a relay, or you could just use it to trigger a couple relays.