1999 Windstar REM Question

[tnut55]

A local mechanic told me that the source of battery drain in my vehicle was the Rear Electronic Module. I know these modules are vehicle specific and need to be flashed. He said they have the tools to flash them but that they need a "new" module from Ford and were having difficulty finding one. Yet I see many used ones on eBay.

Does anybody know, without a doubt, what the story is on these REM's? Can they be flashed or is the flash a one-time operation. Can these modules be repaired? Is there any service out there that will repair or replace these?

[12Ounce]

I've never heard of this problem ... that doesn't mean much, but I have heard of excessive battery drains caused by the rear window wiper not nesting properly ... and that is probably fed through the REM.

[tnut55]

Yes, I read about that issue as well as a host of similar issues. I usually work on my own cars but as I get older, I more readily defer to local mechanics. Plus, this is my grandson's vehicle and I really don't want to get intimate with it.

Here is the situation. The alternator had an obvious on-the-road failure. I had the car towed to a local shop where they confirmed the alternator so it was replaced along with a new battery. I'll add that the shop is normally a good one. They have always diagnosed and fixed what I brought them, usually without a lot of BS and I have trusted their work through my experience with them.

After 3 days, the car was used on a 60 mile trip and then parked for 1-1/2 hours. The battery died, so I took it back in and let them check it out in case either the new alt or bat was bad. The mechanic had it for 3 days and finally pronounced that it had a drain associated with the REM but then could not get a new one from Ford for whatever reason. We needed the car back so he said as long as we disconnected the battery when not in use. Meanwhile they would look for a new REM.

When I told him I could get a used REM off eBay with the same exact serial number, he informed me that these cannot be reprogrammed. I'm not sure that passes the BS smell test. My own research indicates that these need to initialized and programmed (vehicle specific) but I cannot confirm whether we can take any old REM, re-initialize it and reprogram it for this vehicle. I am hoping somebody in the know can answer the specific question.

However, the car just returned from another 60 mile run and immediately after turning it off, we tried to start it. The battery was dead again. So I cannot rule out that the new alt or bat is not bad. I removed the positive lead off the battery and measured the current draw between the battery post and battery lead. As soon as I hook up the ammeter, I draw 2 amps, some relays in the fuse box click and the current eventually settles to 1 amp draw with everything off and doors closed. So I disconnected all the leads to the REM and nothing changes. This indicates the REM is probably NOT the source of the drain, but I don't know this car well enough (yet) to make that claim.

Thus, it looks like my work is cut out for me unless someone who is more familiar with this vehicle can point me toward another cause.

[12Ounce]

You may want to invest in an electrical diagram book for your exact model ... prob $100 or so ... and worth every penny, I think. Easy to follow.

[12Ounce]

.... as a first guess, I would pull all 4 of the power relays to see what happens with each. You can locate the relays if you have owners manual.

[tnut55]

Thx for the info. We just finished going through the engine compartment fuse panel and confirmed that 4 fuses had some voltage drop and two of these were related to the SSP#3 and SSP#4 relays. One was a massive leak.

I found some other posts on the subject. Two top contenders are for a TSB regarding PCM reprogram and bad wiring under the carpet near the driver's seat. One other post I read on another forum mentioned that wire chaffing and corrosion on this model is a common occurrence.

I have wiring diagrams on the way.

I doubt seriously that the REM is responsible at this point, since I can completely disconnect it and the drain remains.

[12Ounce]

You are on the right path ... measuring those fuse test points can show a lot. Pulling those SSP's is a good start for dividing and conquering.
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Yes, this model does have chafing issues ... not all cars, but some, on the main engine powertrain harness ... against the firewall.

[12Ounce]

... and relay contacts can burn and get "sticky" ... not falling "out" as they should.

[tnut55]

I am almost 100% certain both the new battery and new alternator are working.

I don't have wiring diagrams yet and don't expect to for another 4 or 5 days so I am working blind here. However, the journey has begun. I have stripped all the panels out under the steering column and have pretty good access. At least Ford made that easy to do. I did not find anything obvious except one small abraded wire that could short out but not really anything nearby that it could short to. I also found another wire that was installed post-manufacture. One of the crimp connectors had pulled out so I suspect I have another wire with a bare end sticking out somewhere that could possibly short. This looks like some DIY radio cable but it was late and I haven't found the bad splice or even what this wire goes to. A mystery to be followed up on to be sure.

Beyond that, I was dismayed to find that the major chassis cable is routed along the left side of the vehicle by the driver's seat under a metal shield that appears to be riveted into place. Part of the cable breaks out and runs toward the center of the car just in front of the driver's seat and is very tight against the edge of the metal cover. Possible abrasion point? I don't know and don't what to start drilling out rivets until I can convince myself the issue is in that cable somewhere.

So there is not much I can do until I some detailed wiring diagrams and time to work the issue next week.

BTW, the Haynes book is totally useless as far as wiring diagrams are concerned. The are either typical circuits or not detailed enough. The post 1998 circuits don't indicate the REM as part of the circuit and the text does not even mention the REM. For that matter, none of the modules except the PCM is shown in any detail. The color coded wires don't agree with what is actually in the vehicle. Oh well, that's $26 wasted at least for the circuits.

I always post my findings when I solve a problem and this will be now different if I conclusively nail it down.

[12Ounce]

Haynes is a good book for mechanical references. The electrical diagram is too complex for such a small book ... and the circuitry may change from year to year. Haynes should just omit this section.
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The chafing I'm familiar with is under hood and influenced by engine motion. The powertrain harness, on some few units, got routed differently or something ... and can rub against the firewall. This is about a foot or so away from the PCM unit.

[tomj76]

FYI

Motorcraft offers rental of a complete manual set. You can pay for a few days, a month, or a year. A month is less than $25 dollars. I've used them, particularly before I purchase my own hard copy, and found that it was a more complete manual (plus all TSBs) than the one I purchased for >$100.

Regarding your approach, I agree that you're taking the right path to find the problem. The only advise I can offer is (1) use a current meter if you have one. It will give clearer results. A clamp on dc meter is nice (and an expensive tool!) because you don't have to break the circuit to insert it, but you can use a regular ammeter across the fuse terminals to find out where the current is flowing. (2) If possible, use the divide-and-conqure approach. You'll home in the cause more quickly that way.

[12Ounce]

Well, tnut55, you've put a hex on me. I have recently started having the same symptoms...some heavy electrical drain during shutdown. Failed alternator ... I assume due to overload. I find SSP4 always energized ... and SSP3 never energized ... so, I suspect some heavy-current damage/insulation damage somewhere. ?? And this is all at 370+kmiles.
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Stay tuned ... I've just begun.

[tnut55]

Well, maybe we can help each other out.

I received my Ford DVD and the wiring diagrams are excellent. I went back to basics and started pulling fuses. I found that fuses 103, 108, 109 and 114 were contributing almost equal amounts to the total drain. These feed the coils to SSP4, SSP2, SSP1 and SSP3 in that order.

The drain persists when completely removing the REM from the vehicle through all 4 relay coils. There is a splice through C180 that ties all 4 coils together. Breaking this connection removes 2 coils out of the circuit, leaving only the drain though SSP1 and SSP2 coils and this goes to the FEM. So unless there is something going on that I just don't understand, I think I can rule out the REM the technician said was bad.

However, the focus has now shifted to the FEM. I started removing things from that circuit to see if I could isolate the drain to the FEM or to one of the circuits it feeds. Then all hell broke loose with relays quickly cycling on/off when I plugged one of the connectors back in. From there, not much made any sense. BUT, I think that since I had been working on the car all afternoon, I may have run into a low battery condition and things just were not normal. So that's where I stopped for the evening and started charging the battery again. I hope the low battery condition is the culprit.

Anyway, I removed the FEM completely from the vehicle and opened it up just to see if there were any "cooked" components or other abnormalities. All looks pristine. I just LOVE working under the dash, don't you?

Tomorrow, I'll start back with the FEM. The plan was to hook the main cable that runs from the relay coils in only and see what the drain does. I am hoping I can rule out the FEM as the source and point to a different offending circuit. I hope all the crazy relay cycling does not return or I'll be lost.

[12Ounce]

Well, I did nothing today ... other tasks more urgent.
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Sounds like you are on the right trail. Though our damaged areas may be similar ... we have slightly different symptoms. Currently, only SSP4 has a drain in my case, and the coil feed to SSP3 is "open".
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Yeah, working under the dash is just peachy ... I'm a big boy. May remove the driver's seat as a starter.

[tnut55]

Yes, I noted our symptoms were not exactly the same. And yes, I am big too and that seat is in the way. So far, I have not ripped it out but it is a temptation.

Supposing I need a new FEM, I know I can get one off eBay. I am concerned whether or not it needs to be programmed. The technician said it does because of the security, key fob and other issues but he also said a used one cannot be reprogrammed; that it must be new. I can't seem to find definitive answers.