Interesting failure (no start)

[Spartan]

Well, it was bound to happen sooner or later...

So... a month ago, I bought my wife a 93 Taurus SHO. The jokers who had it prior to me didnt do the front 60K service correctly, and it pissed out a bunch of oil. (front crank seal). We get it back, and 10 miles later the trans goes out. (auto)

While waiting for that to get fixed, we put the explorer on double drive duty. Its been ran a lot in the last few weeks, and yesterday it dies completely. Here is what I know:

3/4 shift solenoid is inop, and it throws a KOEO code for it. I still have TC lockup.

When it died, i was thinking it was the EDIS module... until i realized I had no CEL on startup and no fuel pump running. Traced the problem down to the EEC fuse blowing out. All three underhood relays (under the dist box) were replaced, still blows the EEC fuse.

I did some searching, and it appears that the 3/4 solenoid has power at all times when the key is on, and it actuated when the EEC grounds the other side of the circuit.

the EEC fuse blows within seconds of the key being turned to the "run" position. Until it blows, I have a CEL like normal.

I'm guessing at this point that the 3/4 solenoid was stuck (old fluid from the previous owners neglect) and finally got hot enough to melt the internal trans harness and ground out the circuit.... blowing the EEC fuse. After reading, I see that this is actually pretty common. Since I knew that the 3/4 solenoid was having issues already, would this explain my problems? the truck is on the side of the road at the moment, and i have no money for a tow.

One quick question: I cant get my man-arms up next to the trans to disconnect the 3/4 solenoid/tc harness, but I hear that there is possibly another connector somewhere on the drivers side fender apron.... does anybody know what I'd be looking for? I want to disconnect that harness and put a new fuse into the socket to see if it blows. I'm almost certain that this is the issue, since the 3/4 solenoid has been inop for a long time.

 

[Spartan]

Figured I'd give an update....

BTW... 34 views and not a SINGLE response? Thats nice....


Anyways, its exactly what I thought it was. The 3/4 solenoid is grounded internal to the transmission, it stopped blowing fuses after i unplugged the harness.

 

[Robert Nick]

Sorry about not replying earlier. I had the same situation on my of my friend's customer vehicle. The Fuel Pump would not operate. I noticed the Fuse blown. I made a Short Detector out of an old Seal Beam and inserted in place of the Fuse. The Circuit was Dead Shorted because the Headlamp was Full Bright. I unplugged various harness connections until the Lamp when OUT. It was the Transmission Harness. I ended up clipping the wire to the 3/4 Solenoid and Plugging in the Harness and replacing the Fuse. This vehicle had 325,000 miles and was beat to hell. The the customer did not want to fixed the Transmission Solenoid. I guess he is still driving it without Fourth Gear. Glad you found it.

 

[Maniak]

Double check that harness. That harness runs really close to the exhaust manifold. I've found 2 explorers (including ours) that had that harness fall against the maanifold and melt a wire.

That can then blow the EEC fuse which in turn shuts off the truck or just burns open the wire so it won't shift into 4th or lockup (depending on what burned).

~Mark

 

[Roadrunner777]

Yeah, I got through the original post, it started turning into a transmission issue, and, my friend, you do not want my advice on transmissions.

I am, however, a major wire-head. For a '94 the connector you want, wanted was a black connector under the vapor canister. It has 8 contacts, though not all are used. The pink/yellow wire is the TCC, again, for a '94. I only have '94 prints. If I had read all the way to the end of your post, I would have realized this is what you really wanted. Sorry for that!