stay on all the time. Is there a switch or something that could be going out. And if so, where is it located? <br><br><br> Thanks,<br> Joe

 

Check under the driver's seat to make sure the multi-plug for the belt latch switch is still connected.

 

The first quad cabs had what was known as the SCTM or seatbelt control timer module under the middle of the front seat. This box controls the solenoids in the seatbelt retractors during a collision or rollover. Its a little black box that senses G-loading, angle of roll, and time. Any angle greater than 45 will cause the belts to lock up. Any G-load greater than acceptable will lock them up. Plus when the ignition is off, it will lock up the belts to prevent the solenoids from drawing their normal 0.5A current...which will kill your batteries in about 2 days if its not working. When you open the doors the next time you get in, the SCTM senses this and unlocks them before you even get in the truck.

This box was necessary because the Quad Cab seats had the retractors in the seat and the conventional pendulum was useless in a collision if the seat was reclined too far. As the seat was reclined...so was the pendulum. So Dodge installed these boxes and solenoids to assist the mechanical lockup mechanism at times when it couldn't work.

There is a way to test your seat belt system via disabling the SCTM box and checking your wiring to the solenoids. Sit in the truck with the key in the ign. Close the doors. Push in the cigar lighter...cycle the key on-off 3 times leaving it on after the third cycle (do it quick...not slow). Within a few seconds after this...unplug the lighter...and the seatbelt guy will light up on the dash constantly letting you know its in test mode. I think both belts will be locked up at this time. Open each door and the belt on that side should unlock...or vice versa...I cant remember which way it works. This test mode only lasts a couple minutes so be quick. It tests that the ign power to the module is correct...the door jamb ground switches are communicating with the SCTM, and that the solenoids are operating properly and all the wiring is working. Key off the ign to end the test and the guy light will go out.

You should remove and reinstall the IOD fuse before performing the test. This resets the SCTM. The IOD fuse is the constant on power source (pink wire) to the SCTM. Another test is to roll your windows down...shut the truck off and go away. 30 minutes later or so you should be able to come back to the truck...without opening the doors...and reach through the window. The belts should be locked up and not pull out. This tests the timer function of the module to cut the constant on power to the SCTM.

There is a light green wire that goes from the SCTM module to the Air Bag Control Module. Its a &quot;dumb&quot; communication link to the ABCM that tells it the SCTM is working and in place. It sends a 3V signal to the ABCM. If this signal is bad or out of range...the ABCM will light the dash warning guy light signalling a bad seat belt system.

You can also check the solenoids in the seats by unlugging them under the seat and seeing if you get 50-60 ohms across the terminals of the plug. Thats the normal reading.

The simple solution may be to replace the SCTM black box for $95.00. THey sometimes fail for no apparent reason. It could also be a faulty ABCM...which ultimately controls the dash light you are seeing. Its a pretty complicated setup...in fact so complicated and stupid that Dodge did away with it on later models and installed new improved mechanical pendulum systems in later QC seats. No more SCTM box and solenoids are required. I comtemplated getting late model seats to do away with my SCTM...but the air bag module needs that signal to keep the warning light from coming on. And if I leave the SCTM plugged in with new seats...and I dont have the solenoids there, it senses that and will cause the dash light to come on. I was trouble shooting a system that would not let the solenoids shut off after 30 minutes of key off time. Never could solve that one.

Sorry for the long post but there really isn't any switches you can check. Except for maybe the retractor switch which senses if the belt was pulled out. But that wont make your light stay on constantly. Just a few seconds maybe. Even then you have to take your seat covers off to get to it and thats not fun.

Your best off to take it to Dodge and let them do it...or get a 99 service manual and perform all the tests. I'm not a Dodge mechanic and I'm not one to take it to them. But after all the time and money I spent on mine...I should have. After all its you safety were talking about here. And they wont let you drive away with a truck that doesn't have a functional seat belt system. They could be really liable if they did. They would have to find the problem. Its complicated to check all there is to check.

 

Thanks Shovelhead and CTD 2500, right after I posted this thread it stopped lighting up. I don't know why and no Big K my seat belt was inserted properly. ;D As of right now, no more problems. Thanks for the feedback, if problem persists CTD 2500, your diognosis will come in handy. <br> <br><br> Thanks for the help,<br> Joe

 

Unbeliveable! I wish I had read this before I took mine to the dealer and they charged me $250 to replace the seat belt retractor. Both of them stuck when I took the seat out for a repair. The dealer did not know of the electrical sensor and went about replace the driver's side retractor, and ordered the retractor for the passenger side. He told me they both went bad at the same time. Now I find out it could have been reset! I am printing this out and getting my money BACK!

This site is a great source of information! WOW!

 

CDT2500 sent this e-mail to me about the Seat Belt Tensioner Control module or STCM. It was so informative on this subject and included an great "quick fix" idea I copied it and pasted it to this thread. Hopefully, it can help someone else someday as the "99's" get older. While this is not the biggest problem in the world, it sure is a pain in the *** and cost me $250 to fix when the cost should have been $0.

"My truck had a problem where the battery would die if the truck wasn't ran
every couple days. What happened was the lockup solonoids in the retractors
(in the headrests) were not de-activating or "locking up" after I shut the
truck. Basically after 30 minutes of key off...the retractors should lock
up and go dead...ie: no current provided to them from the SCTM. Current
keeps them unlocked...the default is locked with no power. Good idea cause
if your in a wreck and the batteries get destroyed the default is lockup the
belts.

Anyway...I have the Mopar service manual for a 99. I went through the
entire troubleshooting deal and simply determined the SCTM needed replaced.
BUT...a new one did not solve the problem (cost $85). I actually think my
solenoids are bad cause they read more ohms than what the manual says they
should. And for some reason I think they are causing the SCTM to not
function properly and know when to kill the power. Every procedure in the
manual has been checked out OK except for the solonoid ohm values. I have
no clue how much they are but I figured they'd be expensive.

So to avoid the key off draw from the solonoids... I removed a short section
of the SCTM harness (has plugs on each end so it comes right out and is only
18" long) and rewired the SCTP power supply. The SCTM actually uses two
power sources...one from the ignition circuit and one from the "B+" constant
on power supply in the fuse panel. I just wired it so both power feeds to
the SCTM use the key on source. So when I shut the truck off the SCTM
instantly dies and no more current draw. The belts will retract fine...I
just can't pull them back out unless I turn the ignition to "on"...which is
usually the case when I need the belts anyway .

>From my best analysys...I'm assuming the system will still perform normally
during a collision. There is no "seat belt lights" illuminated on the dash.
The seat belt light guy (red color dash light) only illuminates when the
Airbag Control Module senses a problem with the SCTM operation. They are
interconnected by a green low voltage wire for communication purposes
between the two.

Its a tough deal...I hate it...but its what I got. I wish I had the 2000
and up quad cab seats where the retractors are totally mechanical and do not
rely on an SCTM. Kinda funny why Dodge scraped the SCTM controls.
Obviously not a trust worthy system.

I know mine will still work in a crash as the mechanical portion of the
retractors still accomplish frontal collision restraint along with help from
the solonoids and the G-force sensing SCTM.

Its a long story and not easy to get to know without alot of time and a
Chrysler manual. This probably didn't help you much.

Most guys with SCTM problems just replace them and all is well. My
situation didn't work that easy. I just read about SCTM failures on
TDRegister and figured I could replace mine too but it was more than I
expected. Maybe I can someday get 2000 up seats...but the SCTM still has to
remain plugged in to talk with the air bag module or the dash light will
never go out. What a mess really "

 

W O W !!!

It never ceases to amaze me what one can learn on this site. What a fountain of knowledge!!

Me--I'm

Thanks CTD2500

 

CDT2500 also sent this info on how to test your "99" Dodge STCM;

"Park your truck with the windows down so you can reach in and pull on the seat belts. After shutting it off...leave it there approximately 30 minutes...45 to be sure. After that time you should walk up and reach through the window and the belts should NOT be able to be pulled out. If they can still be pulled out something is amiss.

Note: do not open the doors when you do this. If you do the SCTM is attached to the door overhead light switches and the SCTM will "wake up" and start providing the solonoids with 12 volts. Then you'll have to repeat the test again. This timer function is the "T" in SCTM.

Do that and you can go from there. There is also a diagnostic mode you can enter involving cycling the ignition key and the cigar lighter at the same time. It will let you know if your door switches are working with the SCTM properly. DODGE should have gone through all this procedure for you. Its pretty obvious if they look at the SUPPLEMENTAL RESTRAINT SYTEM of the book. Its the Active Restraint chapter and pretty easy to troubleshoot with.

In my honest opinion...there are really only two things that can go wrong with these seatbelt systems. Either the SCTM (non servicable) has electronically gone bad...or the retractor solonoids in the seats themselves are bad. Other than that there is nothing to it. Only problem is the SCTM is $90 and the solonoies are "I dont even wanna know how much". What were yours going for??? I can put them in myself so I wont need the labor bill amount.

Eventually I'll break down and buy me some new solonoids for the seats and try that. Then I can return my harness I modified to normal by replacing it with a new one. That short harness hopefully isn't that much money. If if is I'll just redo mine back to original.

 

Thank you Neil! CDT2500 ROCKS! Looks like I'm gonna get my $250 back! Beer is on me!

 

Just for clarification to modifying the SCTM wiring harness...you'd be tapping the 12V pink wire into the 12V blue...or the other way around. I cant remember without looking in the manual or at my truck.

I'm not sure why the SCTM gets 2 power sources...one being keyed and the other being constantly supplied...only cutting off to the solenoids when the SCTM says "the keys been off for 30 minutes and nobody's opened the door for 30 minutes...so obviously nobody wants belts...goodnight".

With my setup...you can only put the belts on after you turn the ignition on. They will retract with or without power. In stock form when you open the door you can put them on. Guess the SCTM switchable power is there so your belts can be put on incase you get inside, dont start the truck, push in the clutch roll down a hill and hit a tree...you can still get your belts on. All without even starting the truck.

Geico...I wouldn't be so sure Dodge would be willing to give you anything back based on what I know.

 

CDT2500 Don't be so modest! I have already collected based on your post! I'm serious! I faxed them a copy of your post and they agreed with my claim. They settled this afternoon! FULL PAYMENT! with an apoligy! After 3 years!

<-------FREE LEGAL ADVICE HERE! lol

Beer is on me!

 

Help me understand your original problem Geico. You removed the seat and later both solonoids remained locked up when the seat went back in?. In order to get the seat out...you would have to unplug the harness under the seat going to the SCTM. Since the SCTM is bolted to the seat frame you didn't have to unplug the solonoid leads coming from the SCTM going up to the solonoids in the headrests.

However later you plugged in the SCTM after re-installing the seat and under no circumstances would the belts retract? I'm just trying to picture what happened.

This would mean that for some reason the solonoids were not getting any 12V power to unlock both with the key off and key on. Normally they wont lock up but rather remain unlocked permanently.

Guess my lesson learned is that 0.5A Ignition Off Draw (IOD) will kill dual batteries in short time. Troubleshooting complicated seatbelt electronics is...well...complicated. And little black boxes (SCTM's) in Dodges are not as durable as the black boxes found in passenger jets. I think maybe unplugging/plugging in the SCTM without first pulling the batteries or IOD fuse may have somehow jolted the SCTM and killed it. Just a guess but Dodge should have known this. Or at least ohm tested the solonoids first before replaceing. Good for you.

PS: Solonoids do not solely lock up belts in collision. While driving down the road...grab your belt and give it a fast jerk. It will lock up from the mechanical parts in the headrest too.

SCTM's give me a headache ...I'll take that beer now

 

"However later you plugged in the SCTM after re-installing the seat and under no circumstances would the belts retract? I'm just trying to picture what happened"

That is exactly what happened. iF I would ahve disconnected the battery I would ahve been fine.

 

Thank you Geico266 and CTD2500!

I Have a 1998 Dodge ram 1500 Quad Cab and was recently experiencing the 1 1/2 to 2 day battery kill. I measured about a 6 amp draw. After a day of troubleshooting it outside in the bitter cold here in Minnesota, I unplugged the harness leading to the SCTM and the draw quit. With a test light in between the negative side of the battery and the negative cable I plugged the harness back in and depressed the pin switch for the dome light in the door jam and heard a clicking sound in the seats which I later found out were seat belt solenoids, the seat belt solenoids began to cycle on and off.

Now I'm at a loss! What the heck could be clicking in the seats? Armed with only a Haynes manual I was stuck. So I surfed the web and found this site and low and behold Geico266 and CTD2500 had posted info on my exact same problem! Now I Knew I was on the right track.
But Heeding the warning that the SCTM was replaced with no results I was reluctant to rush out and buy a new one at now $110.00 a copy. So I tried the diagnostic test (key on and off 3x w/ cig lighter on then key left on the 4th time and cig lighter off) But this did not work for my 98. So either I did it wrong or it does not apply to my year Dodge. So then I tried the window down walk away and leave it alone for 30 to 45 minutes test. Went back and seat belts were not locked up so I knew something was wrong here.

I am planning on keeping the truck so I was just gonna splice the pink (B+ 12 v Constant) to blue (12v Switched) in order to by-pass the constant 12 v and turn it into a switched 12 v supply. I decided to re-test to verify the problem first and found while moving the harness under the seat the draw would be intermittent. So when I pulled out the wiring harness I found a broken corroded wire on the harness, which was shorted to ground. (probably got nicked from stuffing things under the seats I'm Guessing, then due to moisture in the carpet and the heater blowing the moist air under the seat caused the corrosion) I also found a broken pin connector, don't know if I broke it pulling it apart or by shoving things under the seat or what. So I ended up jumpering the broken pin connector and splicing the broken wire.

(Which I'm pretty sure took out the SCTM), I then Replaced the SCTM and all is good!

I'm glad I found this site and read your postings Geico266 and CTD2500, otherwise I probably would have replaced the SCTM and shorted out the new one!

Great informative posting!

Thanks again!

IronOzzie...

 

Glad the info helped. The SCTM is a tricky and troublesome little box. I checked and checked things on my 99 but eventually had to defeat the harness. I really really didn't want to do that but couldn't solve the problem any other way. I got tired of dead batteries quick.