4R44E (newly rebuilt) intermittent electrical problem? (98 Ranger)

[Still Bill]

Truck ran fine all weekend. Called shop today to tell them it was working. Ten minutes later the kid called me and said it was messing up again.

Shop said there is some kind of aftermarket cruise control box, or something behind dash. Suggested that I remove and then see if it's fixed. So, that's my plan for now.

Wiring diagrams would help me, I guess.

Edit- So, I was thinking that the interior light not working when this happens could be useful. If I follow that wire, I should find where the problem comes from?
What if I put 12V to the light power wire? This couldn't possibly mess up anything else, could it? Maybe it would back-feed the trans circuit and make it work?

 

[tomw]

Before sending voltage down a wire to go who knows where, I would be finding out what the box is, how it is connected, and what can be done to remove it, putting things back to 'normal'.
An add-on unit may have problems that muck around with the ECM or, if equipped, GEM or SJB. The latter two control interior lights, auto door locks, remote door lock, alarm stuff, etc. Get the wiring diagram from bbbind.com if they have it, and peruse. Before sending power somewhere...
tom

 

[Still Bill]

I got the truck to my house today, and it was in the BAD mode. I left engine running when I got home. While we were driving home, I also learned that the wipers quit whenever the trans stops shifting. This, in addition to the interior dome light not working when it happens.

So, I started checking fuses. Not just the fuses, but also whether the fuses have power. I checked light first. Fuse OK, and power at fusebox. Then, I checked wiper fuse. Fuse OK and had power. Just as I replaced it, the dome light came on! Wipers still did not work though. Only lasted a few minutes, then the light went off again. I checked all other fuses on interior box after this, and all were OK. Engine died when PCM fuse pulled. Light and wipers still off when restarted.

Moved to underhood box. Fuse #3 (Shift control according to my diagram) apparently not used in my vehicle. Just as I was checking this, the interior light went on, wipers work, and trans started working normally!

Next, I removed radio, which is aftermarket with 5-way maze plug. A bare wire sparked while removing radio. Probably a blue wire (power while ignition on switch?) I disconnected all the add-on wiring back to the OEM plug.

Next, I tackled the under dash cruise control (aftermarket?). A big maze of wires! Removed them all. Couldn't really get to the "box", but it is disconnected. There was a power wire (with fuse) linked into the OEM radio power wire! This looked fishy.

Sent the boy home with no radio, and no kick panel under steering wheel. Running perfect (so far), but this has been the case all along (intermittent problem).

From last night until I got truck to my house today was the longest continuous time that the trans was messing up.

I now think the trans shop did work hard trying to fix. They even are fixing my other transmission for free (just a remove and replace trans to swap shifter fork on a standard shift).

Fingers crossed (again).

THANKS TO EVERYONE ON THIS BOARD WHO TRIED TO HELP!

 

[Still Bill]

Not working again today! Sigh!

 

[Still Bill]

This problem has become an Electrical issue more than a Trans problem, so I have made a new thread. See here: http://www.therangerstation.com/forums/showthread.php?p=1623301#post1623301

I've copied here what I posted on new thread, but from now on I will just follow the new one. Please use that for replies.

Also: PS: I just received in the US Mail the Conplete 1998 Ranger "Electrical Vacuum and Troubleshooting Manual". Hard copy, brand new. This beast is about 250 pages, and 200 of tham are wiring diagrams. If anyone needs copies of certain pages, let me know.

I WILL FIGURE THIS OUT! I hope it helps someone in the future!

NEW POST:

Hello. I originally posted this as as Transmission problem in other section (http://www.therangerstation.com/foru...d.php?t=176201), but now I think it is more of a general electrical problem.

1998 Ranger 2.5L automatic, no power accessories.

Occasionally and randomly, something happens that affects all the following. It happens once or twice per week, and lasts from 2 hours to overnight. Truck runs great most of the time. No warning lights. Everything works. Newly rebuilt transmission.

SYMPTOMS (all happen at once):

Transmission won't shift above 2nd gear.
Speedometer doesn't work.
Dome light (overhead interior) does not work.
Wipers do not work.
Overdrive light blinks.

Speed sensor at axle is new. Transmission connections and wiring are new. Everything obvious has been checked, including grounds (if we found them all).

We tried replacing GEM with new (used) unit. No difference (still random, same problems).

Today, I disconnected the GEM just for kicks. This was done while the truck was in "Perfect mode." I was shocked to find that EVERYTHING, and I mean Everything, sill worked normally. The only exception I found was that the ABS light did not come on when key was first turned-on. Wipers, lights, horn, AC, brakes - all perfect. We drove 50 miles.

One more thing. It is my son's truck. While driving today with GEM disconnected, he noticed that the speedo was reading 72. I'm sure it was accurate. But, he said that ever since we had the truck (4 months) the speedo would always max-out at 65. I never knew this, and can't swear it's true, but seems plausible.

Can't say of problem is fixed - every time we think that, it comes back a few days later at random. Why have a GEM that doesn't do anything?

Anyone have any insights?

PS: I just received in the US Mail the Conplete 1998 Ranger "Electrical Vacuum and Troubleshooting Manual". Hard copy, brand new. This beast is about 250 pages, and 200 of tham are wiring diagrams. If anyone needs copies of certain pages, let me know.

 

[Still Bill]

Found it!! 100% sure.

So, that was the ABS module I changed previously. Located the GEM on my vehicle. I have all the wiring diagrams. I realized there were some other functions that the GEM also controls on my vehicle, including seatbelt unfastened warning, door ajar light, and key left in ignition chime. We never noticed if those were also affected.

My son said he thought it happened when it was hot (not engine temp, but weather). This explains why more frequent lately.

So, since GEM is next to heater vent, I turned up heater and propped GEM t in front of blowing hot air. Came back 20 minutes later and everything was off (including things like chime that we never noticed before). I verified that GEM was getting voltage from the various hot feeds.

Then, I took GEM into house and put in freezer for 5 minutes - plugged back in and everything works! Took GEM out of its plastic case and held in front of heater - heard an audible click when it shut off 15 seconds later. Disconnected it and waved in air for 30 seconds, plugged back in and it works!

Pretty definite diagnosis, I think!

Thanks to everyone who helped!

 

[Still Bill]

Well, truck has been running fine with new (used) GEM for about a month now.

 

[RonD]

Good work

Thanks for the update and FIX