Crazy Electrical...

[sp33dfreek]

O.k., first off, let me apologize if this ha already been covered, and I'm following a thread already that is close to my question but may not be related to the same end result (2000 XLT W/Electrical problems please help !!!)
My my O.D. off indicator light stops working, 4wd/auto and 4wd/low indicator lights flash together 6 times, then go out, and are inoperative. The reverse lights go out, and the auto lock feature (in drive the doors lock) stops working, and I lose Overdrive and both 4 wheel low and 4 wheel auto. Along with the rear window defrost switch, and the overhead temp. indicator has now started to flash "ICE"..? (It is below freezing)
It has been to the trans. shop once and they removed and replaced part of the wiring harness, the melted fuse block (next to the drivers door), and went ahead and replaced all the fuses instead of just putting the good ones back. They showed me the old stuff, and they have been a reputable shop since I was in high school and are close to our family, but they have told me I have a larger problem when I called them about this happening after their repair. Is this related to the GEM..? Is this an issue I can fix without using a "permanent" garage, or can I just replace a control unit or solenoids.
Thanx everybody in advance !!

 

[superinstaller]

Thats some list, First I would start looking for something visually obvious
like melted or damaged pins , connectors. somthing loose, something grounded to the frame, but an easy try would be to go to a u-pull-it parts yard get a used gem module .
Although if your getting consistant codes flashed from the tranny, I might think somethings loose somewhere, also why was the fusebox replaced?

 

[sp33dfreek]

The fuse box got replace because at the point on the back where the wires connect, (passenger compartment fuse block in the dash) The thing had spots on it where it had actually begun to deform from heat, now that the same situation has begun, I'm not driving it at the risk of losing it, or worse yet having it start on fire while my daughter's with me, that would freak her out..!

 

[superinstaller]

Whats causing that!? is it easy to check for somthing loose, id get in there and check everything!

 

[sp33dfreek]

Just spent some time in there and couldn't find anything. I even checked any scratches from the recent repair. I checked under the hood as well. I haven't pulled the dash open by the GEM (behind the stereo) but will check that area tomorrow. I'm so confused at this point maybe I should drop my thinking back to basics..? Get out the multi-meter as it definitely appears to be some sort of voltage issue, right..?

 

[OneLever]

...the melted fuse block (next to the drivers door), and went ahead and replaced all the fuses instead of just putting the good ones back.

I am going to go out on a limb here and suggest that one of your fuses is the wrong capacity and that you also have a short circuit somewhere. The short circuit would cause a fuse to blow. And somebody trying to do a quick fix might have replaced the fuse with a higher amperage one. This would lead to the fuse box melting from excessive current. You can check this by getting the owner's manual out and comparing the amperage rating of every fuse in the panel against what is listed.

The fuse box should never melt because before it would get that hot a fuse would blow. Is there more information you're leaving out? Such as a car wreck, auxiliary light mishap, etc. ?

 

[sehaare]

As you can see from my post count I'm not an expert on these cars, but I have 3 cars that are 11, 19, and 30 years old respectively so I've had to fix my share of electrical problems.

A melting fuse box is an indication of a short circuit somewhere. Whoever swapped out the last one without finding the cause was just setting you up for failure (or a fire). You'll need a wiring diagram and a multimeter for this one.

You need to document which connections on the fuse box are melting. Next you should see if any of those are unfused. There are usually a very small number of circuits or wire runs that are not fused and if those short to ground there is nothing to protect the circuit and those will overheat. What you are looking for is a low resistance to ground that is not expected. You will need to disconnect the negative terminal on your battery and then check the resistance to ground using the resistance setting (ohms) on your meter. You need to know where each wire is going to or you could be tricked by what appears to be a low resistance.

Good Luck
Steve

 

[budwich]

Just spent some time in there and couldn't find anything. I even checked any scratches ....Get out the multi-meter as it definitely appears to be some sort of voltage issue, right..?

Pretty "novel"... its amazing when looking at electrical problems that one would actually use a meter as a "last resort"... not to pick on you, but it does amaze me for the number of posts that are like that.

Anyways, do yourself a favor. Pick one of your "symptoms", look at the schematic and then take a meter and look at the various circuit "conditions" (voltages and grounds, continuity) that are involved. This will likely point you in a direction that may or may not lead you to a common point of failure IF you are lucky. IF not, with the "state"of your electrical (ie. melted, melting), it is possible that you have a "few gremlins" (still).

Having said that, the GEM is a candidate for multiple failures but I have read a lot of posts with that "finger pointing" and that wasn't the necessarily the root cause.

 

[budwich]

Further reading your first post... you took your truck to a "tranny shop" and they "pulled melt stuff"... hmmm. You wouldn't happen to have a leaky front window... maybe. There have been a few "cases" of such and the result is "ugly" and "fits your descriptions" (ie. melted stuff, stuff not working). The leaks were reported in the center of the window and cause "drips" onto / near the GEM which cause all sorts of "wonderful things". I would still do as suggested (meter and such) but also check for water marks and such in the areas to see if you can find the "root cause".

 

[sp33dfreek]

You know what budwich, you're exactly right... The multi. would have been my first choice but had ( I hate this word ) assumed with the first indicator only showing up as a transmission issue I would bring it to the shop and that would be it... I SHOULD have known better than it being that easy with a very extensive background in aircraft mechanics, the meter would have begun pointing me in the right direction. But I will admit to wanting a quick fix, and to putting the issue in someone else's hands. I took your advise and checked further in and around the fuse area and with everything being new I am un-able to find anything, the fuse that keeps blowing is the 10 amp on location 26... I bought the truck three weeks ago and it obviously had no manual so I downloaded one from the link one of the guys put up here. Now the windshield "SEEMS" to be ok but I went further and looked under the hood for ANY signs of repaint or repair and found nothing. I then looked it up on CarFax and found nothing, but that doesn't mean it was never replaced. Tomorrow I'll pull the stereo and start looking for watermarks and running my meter tests. Thanks guys for all the help... I'll post an update this afternoon...

 

[budwich]

Ok... now you are getting some where... more information.... you didn't previously indicate a "constant fuse blowing". That's a good place to start. Just to back up a bit.... I wasn't "dissing" the tranny shop "work" or the "idea to take it there"... it did seem "reasonable".... I was adding up the "cookie crumbs" and the "path" that took me to the "leaky window problems" others have had with the "same kind of crumbs".

So now you can focus on the fuse problem... maybe. The other bit of "three week ownership" will be tough as your knowledge of "events" might not be enough to know how deep you are in the "alligator swamp". Having said that a "blowing fuse" condition is a lot easier than "lots of things happen randomly here and there", so you should be able to track it down. Unfortunely, I only have 96 drawings... :-( but you want to look at the power feeds for the torque on demand relay/module (if there is such a thing in 2000) as this feed also serves a couple other things in 96 and probably other years.... maybe along with things like indicator lights as they should be easy to check for voltages being there, not being there... to give you more clues. good luck in your hunt.

PS. Actually, fuse 26 in my 96 appears to feed a lot of "stuff" that you have problems with, 4wd solenoids, backup lights, transmission control, etc. Of course, you can meter at the fuse (fuse out), and measure resistance to ground, and go "wiggle / remove" connections here and there. I would check in and around the rear bumper for a backup bare wire feed somewhere... maybe.

Having said that, when does your fuse blow... immediately on insertion?, with key to just "on", or during "start", then "run"????

PPS more questions, you wouldn't happen to have a manual tranny in the beast? Anyways, if your fuse blows on insert, you might want to check around tranny area for the backup switch (and/or tranny range selector switch on automatic) side of things for bare wiring.

 

[sp33dfreek]

Budwich Thanks for all the advice !! This thing IS making me nuts ( It is a '96 by the way, my fault) !! My last toy was a full size Bronco I never wanted to get rid of and things were a little easier to figure out, see I bought this at a buy here pay here for cash and thought I was getting a good deal. I sort of got a tail light warranty... when they can't see the taillights the warranty is over. Haha. so about a week later we got some snow and I put it in 4wd auto ( from neutral, stopped) about 15 minutes later, the trans wasn't shifting into O.D. ( tach. indication), Then the 4wd lights started to flash (both of them together) and I lost 4wd low as well. Now, the lights flashed 6 times. that was the trip to the tranny shop. After they played with it for 3 days, I got it back. The 4wd worked for two days more, Then the same. Is this a better indication of what could happening... I haven't had time to dig into it any further, but next I will check the demand relay? module (where is that) and the thing appears to only be blowing during driving, after it has warmed up. It is an automatic too. I'll go back over your response and make a list to bring downstairs and check next. Thank-you man.
Get back to me when ya' can... I sure appreciate it.

 

[budwich]

more input, more input... wow.... five alive... or can you say "Short Circuit"...

anyways, ok 96 is good as at least the schematics are now the same...

It would certainly be nice if you could nail down exactly when the "blow" happens... and sequences leading up to it. It sounds more like a "bare wire" thing that might "touch" things off with a "bounce" or bang going down the road. Perhaps, try just "idling" in the driveway and shift through gears, forward, reverse and such plus 4w auto 4wlo and see if the fuse goes... of course, it could get expensive as fuses aren't cheap eating them during testing.

Last thing for right now... you wouldn't happen to have daytime running lights???? ;-)

Oh.... I'll throw out one more test item during your idle.... try turning on your rear defrost :-O by chance is that how this started once you got it back... with the nice "warm weather" you guys are getting!...

really lastly... you might have other fuses gone IF your auto locks isn't working ... or IF you put fuse 26 in (and it stays healthy), do your autolocks work assuming you know when they should work.

 

[sp33dfreek]

The rear defrost wont turn on at all, and there are no daytime driving lights but I leave the headlights and fog lights on together almost 80 percent of my driving time. The fuse seems to blow while I'm driving, doing doughnuts, or just "lightly" showing off to my 8 year old daughter... so I think you may have a point on that short under movement scenario... I'll poke around more after dinner... Thanx again man.

 

[budwich]

well the rear defrost "problem" is probably the "camel"..... but checking it is ugly. You have to get into the dash to check the switch (to see if it functions)... but then the switch doesn't do much other than tell the GEM to operate the relay.... BUT the rear defrost relay is in a really ugly place, top right of the dash... not sure how easy it is to get at but it doesn't sound good... may be with radio out... might be visible. Anyways, the GEM grounds the operating coil of the relay and the fuse 26 "sends" the power to operate it... so you should see a ground and voltage at the relay when you press the switch. Of course, IF the relay operates (you should hear a click), the light comes on on the switch to tell you its on. IF you hear a click and no light, then you likely have other fuses gone.... 14 in the Power Dist Box (hood) and 32 in the interior fuse box.

Anyways, not to "belittle" your main problem but would maybe look at the rear defrost a bit closer. Having said that, the operating power (for the relay) passes thru a splice near the headlight switch... so if you trace the "P/O" color wire towards that area, you might get lucky ... of course with your luck, there are probably a half dozen "P/O" wires under the dash in that area.... nothing is going to be easy here. Anyways, hope that helps.

 

[budwich]

finished my "housework" and "feeding my brain", I was wondering a bit more. IF you don't ever touch your 4wd drive "stuff" (ie. leave the switch in 2wd), and you don't play with O/D switch, does the fuse stay "happy"??? My thinking is that maybe you have a solenoid "pulling" too much juice.... at this point, it would be the 4X4 one if things stay happy, IF not, then the 4X2 might be a good "guess".... just a guess though.

 

[sp33dfreek]

Ahh ! The rear defrost switch was pushed when this started to happen after the first initial tranny. shop repair !! the light won't come on (on the button), and it blows the fuse every time I try it... Hahaha dude, you have been doin' this a while haven't you !! The thing is a bit of a pain to try to track but I pulled the stereo out so it shouldn't be too bad. 1 more thing... If I have a cassette deck, With the cd controls on it, shouldn't there be a c.d. changer... s o m e w h e r e... I have almost begun to think, the wires from it are lying somewhere, under the carpet, shorting out as well... I'm gonna' go tear some more things apart for now...
Thanks everybody... post more later...

 

[budwich]

well you are making progress.... BUT, your problem isn't the switch CAUSE the switch doesn't touch that fuse... :-( Your problem is / may be associated with the relay that the switch is trying to get the GEM to operate.... and can't CAUSE it keeps blowing the fuse. I know you don't like meters... so you might just try replacing the relay... maybe. Me I would meter... cause I don't got any money to throw at parts for "testing". Anyways, the light in the tunnel isn't likely to be a train... but it could be your rear defroster now working... I still worry about the "melted stuff" in the first "go around"... that is never good even if they "replaced everything".

 

[sp33dfreek]

I get a laugh when I read your replies budwich... I was hoping to find more than I have, but am bound and determined to track this thing down. It's not that I don't like meters... I don't like the schematic "map of the world" associated with them, believe me I'm disabled military, I'm so broke I can't afford to think about throwing money around... Hahaha ! so, with the dash apart, start to meter everything from the fuse box first, then go to the wiring inside by the stereo. After a few checks I should have a baseline voltage to go by, then do it with the truck running as well, right..?
THANX AGAIN MAN, I really do appreciate this !!!

 

[budwich]

Hopefully, you understand what I wrote but not sure based on your reply. To stop the fuse blowing (26) and maybe save your transmission, you only need to get at the rear defrost relay on the right hand side of the instrument panel and check things out there. As for your stereo stuff, that might be a problem but that is likely another issue which will keep you "warm" around your meter.