On my 1999 Windstar, I've been curious to know what is the main purpose of the FEM and REM and how they work in relation to the wiring system in this minivan. I had a 1998 Windstar cargo van and I never had the electrical problems with it like I'm having with the 1999.

Also, has anyone ever heard of anyone building or designing some way to bypass these units to eliminate one source of electrical issues with these vans?

 

The general idea was to eliminate yards of wiring and expense at the time of build. So now the expense is on the customer. Certain functions have been designated to the modules instead of the usual hard wiring.

 

If that is so, has anyone experimented with finding a way to bypass those modules?

And hanky, what functions are controlled or monitored by them?

 

If you have a concern I could tell you which module controls that because the list is somewhat long.

 

Well, I'm back because this van is still pissing me off.

To start with, it was all going fine until 3 weeks ago when the battery was drained. Charged it up, tested the alternator, and all seemed fine. I figured I'd still check all the circuits by using my multitester and using it to look for voltage drains. When I got to pulling the fuses in the fuse panel in the interior the major drain stopped when I pulled the fuses for the REM. And I did the same to the underhood fuse panel, of which the drain dropped some more when I pulled the fuses for the relays associated with the FEM and REM. The relays themselves were warm, but not hot.

Why would there still be power to those associated relays even with the ignition turned off? I hear the relays clicking when I connect or disconnect the battery.

Also, don't know if it's related, a few years back I took the instrument cluster out and resoldered some of the connections, and all was good till a few months ago when the needles would stop moving until you hit the dash above the cluster, then they would work again. Would anything in the cluster trigger this power drain?

 

So everyone knows what we are talking about,

FEM= Front Electronic Module

REM= Rear Electronic Module

In the past when you operated an accessory you operated a switch and the wiring went directly to the component.
With the electronic modules ,
now when a requested function is desired, the request now goes to a module and the module forwards the instruction to the component(s).
This is done to save on wiring and weight, believe it or not. Now if the request is not received or the module malfunctions for whatever reason or the component doesn't respond, the problem now is to determine where the break down took place and take measures to correct it.

Yes There are some functions that go thru the inst cluster and if there is a problem within the cluster , it can affect battery current drains. If you suspect that to be the problem you might consider sending the cluster out for repair or replacing it with a known working cluster. The numbers should match. If there is a modified version ,the Ford Parts dept would have that info. There are some problems a skilled tech might correct, but best to leave that to someone who has the tools and information.