Bronco Switch, 95 to 89

[Angie Lu]

I need help with installing overdrive transmission. The new transmission has been taken out of a 95 EB Edition Bronco and is being put in a 1989. The wiring does not match. Any ideas on how to make this switch work? Right now I am unable to cut overdrive on and off.

 

[BLADE262US]

The 95 would have been an E4OD and the 89 was more than likely an AOD . Did you swap computers as well ? The E4OD requires the computer to operate . /emoticons/[email protected] 2x" width="20" height="20" />

 

[Angie Lu]

The original transmission was just a 3-speed, no overdrive. That is where I am running into the problems, but I have all the wires and computer from the 95 for hook-up. Do all the wires have to be switched out between the Broncos or what is the easiest way to complete this switch, Thanks?

 

[Broncobill78]

At an absolute minimum you'll have to swap the EEC computer from the 95' but it may be more complicated than that. Did the 95' have a different engine from what your 89' has ? The E4OD that came out of the 95' will need one of two things in order to work. It'll need either the original EEC processor that the 95' had OR it will need a stand-alone processor *designed* to retrofit a late model computer controlled tranny into an earlier vehicle. While Jegs, Summit, or one of the other large online/mail-order speed shops may well carry one, the only stand-alone that *I'M* aware of is the one from Baumann Electronics http://www.baumannengineering.com/tcs.htm . If you go with the stock EEC processor than you'll have to have the same displacement engine in your 89' as the 95' had otherwise the processor won't be happy. If they aren't the same then you'll need a junkyard processor from an E4OD F-truck or Bronco that matches the engine in your 89'. Beyond that you'll have to do a bit of research because I think the 95's had a few more sensor inputs than the 89's did so you'll have to do a little reverse engineering and add the appropriate 95' sensors to the 89' before the EEC processor will be happy. Now to be honest I've never *personally* tried this swap so it's entirely possible that the 95' processor will hook-up and even though it isn't getting all the sensor inputs that it wants to see the transmission half of it will work just fine. I honestly don't know I'm just trying to send you into the project with your eyes open and all the available info. If you can get hold of the 89' and 95' factory EVTM manuals you'll be able to tell for sure since the EVTM (Electrical, Vacuum Troubleshooting Manual) gives you a very specific breakdown of how the EEC operates, WHAT sensors it has AND where each one is located. This is exactly the info you'll need to know if they have the same inputs and if not it'll tell you where each sensor can be found on the 95' so you can go & snag it. I don't happen to own *either* manual but I DO have the 88' factory service & EVTM manuals. The 88's are identical so if you'd like me to scan & post THAT info just let me know. If there are additional sensors on the 95' it may well be quicker & easier to just use the stand-alone from Baumann and be done with it but since YOU'RE the guy laying out the coinage you maybe have a different opinion /emoticons/[email protected] 2x" width="20" height="20" /> Let me know if the scans will help.

 

[BroncoJoe19]

I have '90 with an E4OD trans. I am not going to pretend that I have any idea of what will be involved in making the change that you propose, but I do have a thought in the matter. I wonder if you could find a '90 computer and wireing harness, would that work easier for the swap.

I am pretty sure that a '88 uses a MAP sensor as does my '90. The '95 would have used the MAF system. I don't know if it is difficult to change from one system or another that it why I am suggesting tohe posiblity of using an older computer, (but one that was designed to work with and control an E4OD.)

ANother difference that I am aware of is that the '90 uses a VSS Vehicle speed sensor mounted to the speedometer cable where it inserts into the transfer case. The '95 does not; the sensor on the top of the rear diff serves dual purpose... antilock brake, and VSS.

Good luck with this project.

Please share with us what you learned by doing it.

 

[BLADE262US]

If you had the entire 95 and could pull the dash out and replace all the wireing youd be ok . If you have to piece it together you will still be ok but will need a very good schematic of both yrs to make sure everything is right . BroncoJoe is right the harness from a 91 would work best for a couple reasons 1 the overdrive cancel button for the E4OD in 90/91 was mounted on the dash to the right of the steering wheel so that switch plate will pop right into your dash and look factory . 2 The connector on the drivers side lower firewall that connects the cab harness to the front harness is round for 87-91 and in 92 with the body change they switched it to a square one so if you were to put the 95 cab harness in youd also have to switch the front harness . In the 95,s though the VSS is not fed from the rear end that one handles the antilocks . The E4OD has an internal speed sensor that feeds the pulse signal to the PSOM ( programable , speedometer , odometer , module that is located to the lef of the radio opening in the dash ) So that will need to be wired correctly because the EEC uses that signal as well for timing and fuel calculations . If you went with the 95 harness youll have to use the 95 dash assembly as well which it will fit right in there but you would have to do this because 92 and up have no speedometer cable its all electric driven off the PSOM . When I swapped mine out to the Baumann ( $400 ) I did it because the rear end I was useing was a full flot dana 60 and had no speed sensor and I was useing a carborated engine that I had already built a few yrs back and wasnt suited for injection by the cam I used . If I were doing it and the 95 interior was nice and this is the route you defiantely wanted to go Id swap in the entire 95 harness that way you know it all works together . I can get you the pin numbers for the VSS out of the E4OD if you need them dont remember if its in the black plug or the grey one right now . I do still have the computer sitting here from mine it was for a 91 with E4OD and 5.8 , Id sell it if you decide to go that route /emoticons/[email protected] 2x" width="20" height="20" />

 

[BroncoJoe19]

In the 95,s though the VSS is not fed from the rear end that one handles the antilocks . The E4OD has an internal speed sensor that feeds the pulse signal to the PSOM ( programable , speedometer , odometer , module that is located to the lef of the radio opening in the dash ) So that will need to be wired correctly because the EEC uses that signal as well for timing and fuel calculations .

Blade,

Not that it really matters, but I am certain that I read that the anti-lock sensor performs dual function and sends VSS info to the computer in the newer models ?1992? and up.

?Steve83? did a write up on how to program the PSOM after one changes tires, or gears. I am pretty sure that is where I read about it the sensor in the rear serving dual purpose.

No need to research it, it isn't important to me. Enjoy the rest of the weekend.

 

[Angie Lu]

Thanks for all the help! On the 89, there is a round wiring harness and a long flat wiring harness. On the 95, there is an oval wiring harness and a long flat harness. It looks like the two flat ones will match up. Does this mean I can just change everything on the motor's side or do I have to match that with the dash of the 95, in doing this will I have to change the other cluster of wires as well.

Quick note: the transmission is not shifting, only 2nd to 3rd. It doesn't seem like it is has 1st. Would this be normal for E4OD with no computer hooked up??

Sorry for all the questions.

Wiring.bmp

 

[BroncoJoe19]

Thanks for all the help! On the 89, there is a round wiring harness and a long flat wiring harness. On the 95, there is an oval wiring harness and a long flat harness. It looks like the two flat ones will match up. Does this mean I can just change everything on the motor's side or do I have to match that with the dash of the 95, in doing this will I have to change the other cluster of wires as well.
Quick note: the transmission is not shifting, only 2nd to 3rd. It doesn't seem like it is has 1st. Would this be normal for E4OD with no computer hooked up??

Sorry for all the questions.

I am guessing that the trans went into "Limp mode"

http://broncozone.com/forums/index.php?sho...limp+mode\

 

[BLADE262US]

When the E4OD computer is not hooked up it will only move if manuall put in 1st or 2nd gear . If you put it in drive it will slip like crazy . The long skinny connector your talking about is the one to the right standing in front of the vehicle that one is for the EEC that plug will probably plug into the other computer but some wires will be missing if you go from like an 89 where there was no E4OD to a 95 or vise versa . Easiest way to keep yourself out of a wiring nightmare would be to swap the entire harness even the headlights are pinned out different between the 1987-1991 / 1992-1996 . Or go with the stand alone controller /emoticons/[email protected] 2x" width="20" height="20" />

 

[Broncobill78]

Thanks for all the help! On the 89, there is a round wiring harness and a long flat wiring harness. On the 95, there is an oval wiring harness and a long flat harness. It looks like the two flat ones will match up. Does this mean I can just change everything on the motor's side or do I have to match that with the dash of the 95, in doing this will I have to change the other cluster of wires as well.
Quick note: the transmission is not shifting, only 2nd to 3rd. It doesn't seem like it is has 1st. Would this be normal for E4OD with no computer hooked up??

Sorry for all the questions.

No problem with the questions but we're kinda back where we started. Unfortunately you have one of two choices if you want the E4OD to work. Either retrofit the 95' EEC processor & harness (as Blade mentioned you'll need to repin the headlight connectors in order for the hi-lo beams to work) OR you swap in the stand-alone from Beaumann. That's it, those are your choices. The E4OD will NOT work without the proper processor. The harness is pretty much mandatory but you *can* get away without it if you have all the appropriate manuals, several spools of wire and a *whole* bunch of spare time & patience. without the harness & processor you're going to have problems.

Other than that about the only other option you have is to swap in an AOD. That's what you're 89' would have originally had and it'll still be an overdrive tranny but it's mechanical and doesn't require processor control in order to shift, but if you want the electronic transmission to work you will simply HAVE to install the EEC processor (AND the harness than it needs) or swap to a stand-alone transmission controller. There "*are* no other solutions to this one, not that I'm aware of anyways.