Just made a long trip from Central Oregon {where we live} to Waynesville Missouri and back in the truck I have in my signature. Truck ran great but for one problem that occured on the way back. We were doing around 78 mph and the OD came off creating a small panic for a few seconds as the truck went way down in power. After engaging the OD button again all was back to normal and it never happened again {the Ram has 130,00 miles on it}. Can't detect any problems with the truck as far as shifting through the gears at all. The Cummins purred like a kitten and ran flawlessly. Thanks in advance for any input.

 

Hey there,
I have a 1995 with the auto that does the same exact thing. It does it at weird times. I have noticed that it will kick out of OD a couple of times in a row but then stay in for the rest of the trip. I was told it could be the throttle position sensor going bad. I think the tps was around 200 bucks so I haven't replaced it. I guess a little corrosion and the tps will function incorrectly at times. I hope this helps.

DK

 

It's the TPS, they don't last forever and tend to wear out in the throttle position you use most, like cruising at highway speed.
Some people say they've had luck cleaning them but I've found that fix to be short lived and a waste of my time. A new TPS is available at most autoparts for around $150 and is very easy to install yourself.
Another solution is to install a lockup switch that will prevent the gear hunting associated with a failing TPS. Very simple and cheap.
Instructions> http://www.tstproducts.com/Torque%20...p%20Switch.pdf

 

An other possibility could be a break sw. just out of adjustment , I bought my truck in MO. & had it drop out , then went to replace & adjust , it would not stay adjusted , every so often it will turn off the cruse & drop out of OD , I think that the adj. is so close , that with an older truck there may be some wear in the peddle linkage & it can bounce when driving over bumps / whatever & hit sw. .
I have confirmed this by lifting break peddle with foot , then all works , but that unadjusted the sw. , same when running dyno .

 

Thanks for all the good info. I was in cruise control when this happened. I generally do not drive that fast only when in states that have their interstate hi-ways posted at those speeds. The paper work I recieved from the previous owner had a tps installed shortly before I purchased it from him. That was about four years ago. I average about 6000 miles a year on the truck and just about put that much on this last trip. Anyway nothing lasts forever and I will be changing the tps if this happens again.

 

Test anything 1st , before replacing , unless your just trying to keep the economy going .

 

Hey Bill (infidel),

First of all, I want to say that I always enjoy and appreciate your posts, they are very informative.

I very recently acquired a bone stock 1995 12V 4x4 auto with 212K miles and it was demonstrating the typical TPS related issues of 3-4 shift problems and hunting in and out of lockup. Being a 24V manual transmission guy, I studied up on here and started trying out the tips and tricks to fix the issue without buying a new TPS (which are now $266 at NAPA for some reason). I first cleaned the filthy battery post connections and this seemed to "ease" the problem. Next, I cleaned the underhood body grounds which eased the problem more, meaning less frequent occurences but still happening. I checked the brake switch and it was good so no changes there.

Then I cleaned the TPS connection with contact cleaner, put oxgard paste on the terminals and dielectric on the weatherpack which seemed to "cure" the problem but only for a few minutes of driving. Next, I cleaned the tranny temp sensor which was pretty dirty, but then still had intermittent issues.

But, while under the truck cleaning the trans temp sensor I noticed a broken factory ground strap that went from a lower bolt on the driver side bellhousing directly to the driver side frame (only 6 or 7 inches in length). This morning I made a new strap out of 10g wire (heaviest I had) and also another for the passenger side and ran it to the passenger side battery ground then drove the truck solid for over 2 1/2 hours and never had the problem occur. This seems to have fixed the problem for me (knock on wood).

If not its on to pots for the TPS and trans temp sensor

thanks again,

-Kent

 

Kent, I think whats happening is the days of just one ground right at the battery are over.
Seems that multiple grounds are needed all over vehicles with computers to keep the electrical noise down even though just one ground will give the negative side of 12 volts everywhere on the vehicle.
I've never tried it but have read that one way to see if there are bad grounds on a vehicle is using a voltmeter that measures millivolts. Put one probe on a negative battery post and the other in the radiator coolant, not touching metal, engine running. There should be zero voltage, if you get a reading there is a bad ground somewhere. Good luck finding where though.

The TPS price from Napa must have been the retail price that they don't really chage anyone except mechanics who pass the price on to customers even though they get a discount on parts later.

 

Hey Bill,

That's a neat theory with the coolant and millivolts. I wonder if bad electrical grounds are causing the formation of scale in a lot of radiators?

I talked to a good friend yesterday while I was working on my truck and bad electrical grounds (due to wet sawdust) were burning up the bearings in his sawmill. An elderly gentleman found the problem for him in no time.

-Kent

 

My understanding is that bad grounds cause electrolysis which turns the coolant acid which then starts eating the entire cooling system starting with the radiator.
Bad situation that often occurs after amateur electrical work or a collision.

 

Well the previous things I did turned out to have NOT fixed my problems. They came back with a vengeance.

I've had the '95 12V for a little over a year and 8K miles now and I hope I have solved my lock-up problems for good this time. Since my last post on this issue (see previous post above), I have replaced the battery cables, which I cut open and found the excessive corrosion I figured was there.

After all I had this, I was still having the "in and out of lockup" issues. A little over a month ago, both batteries died (both registered a whopping 8.4V on the DVM). I bought 2 new batteries and still had the issues. I had hoped the new batteries would have filtered the noise better. No dice.

I came across a post that mentioned adding a ground strap from the alternator bracket to the passenger battery negative, so I did that and at the same time I wrapped the entire length of the alternator negative wire with Reynolds Heavy Duty aluminum foil and electrical tape.

I have driven the truck every single day for the past month and haven't had the lockup issue once, which was occurring several to many times per day.