Turbo Tuff,

The E4OD (Electronic 4speed OverDrive) uses a computer and several sensors to shift. The brains of the decision to shift is the PCM (powertrain control module). It uses several sensors to give it information about what the vehicle is currently doing and then shifts, or doesn't shift, accordingly. The sensors are: RPM sensor, FIPL sensor (Fuel Injection Pump Lever), VSS (Vehicle Speed Sensor), and the MLPS (Manual Lever Position Sensor).
You know where the RPM sensor is already.
The FIPL is located on the throttle of the I.P. It moves with the throttle to give the computer an idea of how much throttle is being applied.
The VSS is located in either the tail of the Transmission (early years of the E4OD) or in the differential (later years of the E4OD). It senses vehicle speed.
The MLPS is located on the driver's side of the Trans. where the shift linkage goes into the Trans. It tells the computer what gear the manual shifter has put the transmission in.

You're right, there is a connector on the passenger side of the trans. which is the harness connector for the solenoid block. It definitely is a problem area. If your locking tabs are broken off and/or the rubber gasket is bad or missing, it would be a good idea to replace the connector. You can go to a tranny shop and buy a new one for about $30 (U.S.). I, personally, have had problems with water getting into the sol. block pin area (which the locking tabs and gasket are supposed to seal out) and have had the pins short so that the trans would not go out of 1rst. You can pull the connector off, clean and dry the pin block, apply some dielectric grease to the pins and then plug back in. However, it won't cause your tach. not to work. That is the sole responsibility of the RPM sensor.
I don't think I've sent you a zipped file for the E4OD. It has test procedures on the above sensors, plus other helpful info. If you will click on my profile, send me an FTE email, put E4OD in the subject line and your personal email address in the body, I will get the file off to you. Would make a great back up if you haven't got the time or ability to post a question. R.A.

 

Thanks dieselzen.
The RPM sensor is working.
I decided to goto the Modular fuse box under the Hood and check fuses.
I found the top right corner fuse 20 shot...
Gotto run to the store for a box.
I'll post back in a bit after I replace it.

I sent you my e-mail address to your FTE address,that will sure come in handy...thanks.

 

OK...
I replaced that 20Amp fuse and that was it! But...
When I started the truck the tach moved , the OFF light was NOT on!...then the tach dropped and the OFF light came back ON!!
I shut the truck off and went and checked that 20amp fuse and sure enough it was BLOWN!!

What's happenning??

I'll run out and grab another 20amp fuse.
But I'll wait for a response from the forum before doing anything.

 

I had an intermittent tach on mine. I replaced the rpm sensor and it did not solve the problem. The RPM would drop once in a while. A month ago, I went to an electrical shop for an alternator problem. The guy said that my connector on the altenator was in bad shape. He rebuilted the alternator and replaced the connector at the same time. He said that this connector had something to do with the RPM. Do not know if he is right but the RPM never dropped again.

 

Well this FUSE is obviously for the Tach and OD light.
What I need to know is WHY this particular FUSE is blowing all of a sudden.
What is this FUSE assigned to?
Why is it blowing?
What would cause this particular fuse to BLOW?

 

Turbo Tuff,

I sent you the zip file tonight. Should be there for you to download.
I don't know what to tell you on the fuse. I have an EVTM for the 1990 year Econoline but it didn't have a tachometer as a stock option. Also my van doesn't have a fuse box inside the engine compartment. I have a 1992 Ford manual on CD but I haven't found the schematic which would show the wiring for the tach. on the F-series. Will keep looking.
Does the block where the fuse came out of have a number on it?

 

Hey dieselzen,
I got the zip file,thanks.It was to dark to go out tonight and try anything,I'll wait till morning.
I have 2 Black plastic boxes under the hood up on the fenderwell on the driver side.
One is small 1 1/2" x 2'' long,it has 2 black square fuses with numbers on them,I didn't pull the out.
The other black box is bigger.It's 4"x6".On the right side are 5 1"x1" blk fuse slots(only 3 have fuses).The other side of the box has oh I don't,guessing now 10 to 12 horshoe type fuse(this one is a 20A yellow)It's about 1/4" thick,1''wide,1"long with two metal flat prongs.

As soon as I replaced the blown fuse and started the truck,the tach worked and the OD was working(the light was not on.
But then after 20 seconds the OFF light came on and the tach dropped---the had blown again!

I have another 20A fuse but at $4.00 a pc. ...well they just blow anyway so thats a waste.

 

you could buy a 20amp circuit breaker and install a couple of wire leads with spades then plug that in place of the fuse.this might help track down what sounds like a bare or corrded wire grounded out some where.i used this method before and it sure does save on fuses when tracking down shorts.

 

Turbo Tuff,

I'm just going to throw out some ideas.

Have you got a schematic of the electrical system? If not a Ford EVTM, then at least a Chilton's electrical schematic? If you could find out the color wires which are hooked up to that 20 amp fuse, you might be able to find it on an electrical schematic and see what other components use that power wire.

Have you messed with the electrical wiring recently? Like installing something? What about the Solenoid Pin Block? Is it dry and the connnection tight?

At least this problem isn't keeping you from driving the truck. The transmission shifting isn't being affected, is it? If not, you can always wait til a bit warmer weather to lessen the pain of an electrical .

R.A.

 

Hey dieselzen,
Actually the cars running now and I'm on graveyard so the wife can have it during the day.
The truck ,driving it like this is a little sluggish on take off but it does shift properly.
I'm not going to use it until I can figure this out.
Tommorrow morning I'll get out there and check every thing,including the RPM Sensor again as well.

That black box is this:
Computer (Ford calls it PCM- Power Train Control Module)
On most models it’s located under the hood against the firewall on the driver’s side near the hood hinge.)

I read this in the zip you sent article titled:
.
Before or after overhaul, diesel only. 4th gear starts in "D" and scan tool won't work

The TECA relay provides power for both the controller and the solenoid block on the 7.3L diesels. If the relay or connection is bad no battery voltage goes to the solenoid block. No battery voltage to shift solenoid 1 and 2 means 4th gear starts in "D", and 2nd gear starts in positions "2" and "1". No battery voltage to EPC solenoid produces high line pressure. If there's no power to the controller, the scan tool won't work.

Would this be the cause of me having to give it a little extra revs to get moving?

 

I'd remove that the box that the suspect fuse is in. Check the color of wires and check them back to either the solinoid block/rpm sensor, or whereever they go. You've got a short there somewhere.

The diff mounted speed sensors are a notorious sore spot on Fords. Double check the connex on that one. If it gets water in the connector it'll cause major headaches, till you dry it out. Make sure any of the connex you check still have their rubber seals in them and apply a little dielectric to them when you plug them back in.

 

Turbo Tuff,

What you quoted is known as "failsafe" or "limp" mode. Here's an experiment for you. Unplug the Solenoid Block Harness connector from the transmission. This will put you in failsafe mode, i.e., Drive will be 4rth and steering column shift positions 1 and 2 will be 2nd (I used failsafe mode a while back to shop for a new sol. block connector).
Attempt to start out in the normal "Drive" position. Does the vehicle act differently or the same?

If I had the problem you're describing I'd:
1. make sure the sol. pin block is dry, the pins are clean of corrosion, have dieletric applied, the gasket is where it's supposed to be, and the locking tabs are there doing what they're supposed to.
2. check the grounds of the T.E.C.A. and the T.E.C.A. Relay.
My van EVTM shows there are three ground wires on the T.E.C.A. and one ground on the Relay. But they all splice in (on the schematic) and run to the negative post of the battery (Your guess which batt.). The colors of the wires for my van in 1990 are for the Relay, black /w light green stripe. The colors for two of the T.E.C.A. grounds are black w/light green stripe with the third grd. being orange w/yellow stripe.

It's getting late. Post back with results when you have time and I'll research the best I can in the meantime. R.A.

 

OK I'm ready this morning...
Where do I find the sol. pin block ?
I want to check it and make sure it's dry and not damaged.
I'm having a coffee so I'll wait for a post back because I have no idea where to look for it.

 

Hi turbo tuff. If it is the same as my 1991 4x4, the solenoid block is on the right, passenger side, of the trany. If you look on the right hand side, of the transmission, you will see a connector, just unplug it, clean it, use plenty dielectric or vaseline. Mine was quite dirty when I unplugged it. If the rubber is not sealing, just seal it back with resistant silicone.

 

Just came in from the truck.I went to the Oil spout and off to the right there is a 1"nut with 2 wires coming out of it.
The wires are bared about 11/2" up the wire???
Is this the RPM Sensor?
Can I undo the nut and fix the wires?

Thanks Kidoo.I'll do that next.