Strange electrical issues help please

[bob93explorer]

This issue has been posted several times in the past 10 years, but none of those posters followed up to explain their fix..........

1993 limited 4.0 4wd

Dome light, radio, drivers electric seat, all not working and the unlock button flashes the headlights! Also the remote does not work - but its battery is ok.

Please advise.

Bob

 

[bob93explorer]

update: This problem started after I drove on a somewhat rough gravel road. Also I have checked all the fuses. The only one that made a difference was removing the 60 amp fuse panel fuse from the PD box.
I removed the panel under the steering wheel and can feel a loud clicking (when I push the "unlock all locks" button on the Driver's side door panel)from 2 units the dash sort of behind the A/C controls and the radio. Is that the GEM unit? It clicks like a relay would and the headlights flash!
I have read a few related suggestions here about a LOM unit under the center console; the ignition switch; GEM unit. This is driving me crazy.
This vehicle runs great; 1 owner, never off roaded.

I pulled the codes off it: 111 no problems found and 512 - that's the battery disconnect code - no problem there either.

 

[larrydd999]

Bob, since nobody has replied yet I'll give my opinion (since I haven't had the problem). You have a bad ground somewhere in the system, most likely behind the console. My reasoning is that you mentioned a rough gravel road and that the dome light, radio, and driver's electric seat are not working. Since they are on different circuits & fuses a single bad 'hot' connection is unlikely to be the problem, but it's not unusual to have a loose ground connection to the chassis or body. If you have a digital multimeter (DMM) your easiest (probably) place to test for voltage would be under the driver's seat at the connection for the power seats. Look for a live 12 Volts to ground but not between the wires at the plug. You might have to operate the seat to verify no voltage, there may be enough 'leakage' DC to operate the DMM but not the seat.

 

[bob93explorer]

Larry, you are the only one to respond-thank you. Do you mean I am testing the wiring at the electric seat switch? The wiring bundles under the drivers seat? or a chassis ground under the drivers seat?
I have been googling this for days and plan to work on it tomorrow am. This car is one owner w/ original battery cables, starter, solenoid etc. Overall in excellent shape. I am going to check the cable and all under car ground strap connections first, then move to the seat area as you suggest. Did I mentionthat the keyless entry quit working too? It did - and the fog lights. The car still starts and runs fine - A/C too.

This driving me crazy - and my better half ( her Explorer ) is waiting for me to fix it

 

[bob93explorer]

Larry, when you say console, do you mean the dash?

 

[BKennedy]

Easy way to check ground is to find the ground wire on one of the items giving you issues. Run a new wire off that ground wire to a convenient place to make a new ground to the body, like under the carpet, in a kick panel, etc. If your problem goes away, it was the ground. If it doesn't, it will not hurt anything to have an extra ground.

 

[bob93explorer]

Which ground is most likely to effect so many unconnected circuits?
door lock, headlights, drivers seat, door chime, dome light(not dash lights), fog lamps, key fob?
The other switches on the drivers arm rest all work-mirrors, windows. Truck starts and runs fine otherwise.

 

[Roadrunner777]

Hi, I read your post earlier. I have been trying to find a block of time to get into the service manuals to help you, but it won't be soon. However, I want to keep you from a wrong path. These items do not have a common ground. Just for starters, the front light groups (left headlight, left turn signal, etc...) have their own ground. Sorry I cannot help more at this moment.

 

[bob93explorer]

roadrunner, I look forward to your help. I only have a chiltons-maybe your service manual can help.

 

[bob93explorer]

I know this has happened to other posters but it was up to 10 yrs ago and they did not post their fixes......are any of those posters still out there?

 

[BKennedy]

Roadrunner is right, I pulled my 1994 electrical service manual and they are not on a common ground. Maybe you shook loose a connection? On the firewall below the master cylinder, there is a large circular white electrical connection. with a large bundle of wires. Its for nearly everything inside the passenger compartment. It is supposed to be held in place by a bolt in the center of the plug. It should be covered by a black cover. Pull the cover and see if its loose. If not, try loosening the bolt, pulling the connection and look for dirt, corrosion, etc. Clean it up and re-install. Other than that, I got nothing..

 

[bob93explorer]

BK- thanks I'll check that next. Here is where I stand.

I've checked the negative battery cable at the engine block - seems fine and tight. I only found one chassis ground strap in the rear of the vehicle drivers side - it seems fine. I checked the relays and connectors left rear near jack storage - all are dry, clean and like new. Checked under the carpet left rear seat door trim bundles like new. Pulled drivers door master switch panel looked under it - seems fine.

Truck starts fine - lots of juice. I am using my quick disconnect to power and unpower the vehicle.

NOW: under the drivers seat I pulled the connector apart looks find BUT - I found some kind of key fob control in a little holder with a single button and single red light. This vehicle has a factory security system. is this related to that or some kind of reset device? It must not activate often because the battery in it is 21 years old.This fob is obviously hidden by the factory in that location. What gives?

Next? I will check the main harness at the firewall as suggested-it is not protected by a rubber cover - that's not good. But I did not run thru water. Maybe it is loose. Then I will check the bundle coming thru the drivers kickpanel from the dr. door. And the actual seat switch. Then I will have Jane tap the unlock button after I pull each individual fuse under dash to see id any will stop the headlight flash condition.

Anything else?

 

[BKennedy]

I have no idea why the factory would hide a alarm key fob under the seat. Sounds like that is what it is to me. If the battery is 21 years old, I would install a new battery. Sometimes when they are going bad, the electrical system acts up due to inconsistent voltage / amps. I would replace a battery that old because when they go bad, they just die and leave you stranded wherever you are.

 

[bob93explorer]

Update: I pulled the main harness apart/sprayed it with contact cleaner and reinstalled-no effect.

BUT: Jane hit the unlock button to flash the headlights for me as I pulled each fuse under the dash. NEWS: pulling the horn fuse killed the unlock/flash. No other fuse had an effect on the situation.

Unlock doesn't work yet but pulling the horn fuse cut the power to it. Also, reinstalled the horn fuse, + pulled the horn relay( I think: the brown one clipped to the metal underdash panel) and that also killed power to the unlock button.

Now, there are 2 relays under/behind the a/c controls that both click when Jane hit the unlock/flash button. Don't know what they are - but both have wires that go up sort of behind the radio. Any guesses on all this? Thanks!

 

[L.A.X]

Update: I pulled the main harness apart/sprayed it with contact cleaner and reinstalled-no effect.

BUT: Jane hit the unlock button to flash the headlights for me as I pulled each fuse under the dash. NEWS: pulling the horn fuse killed the unlock/flash. No other fuse had an effect on the situation.

Unlock doesn't work yet but pulling the horn fuse cut the power to it. Also, reinstalled the horn fuse, + pulled the horn relay( I think: the brown one clipped to the metal underdash panel) and that also killed power to the unlock button.

Now, there are 2 relays under/behind the a/c controls that both click when Jane hit the unlock/flash button. Don't know what they are - but both have wires that go up sort of behind the radio. Any guesses on all this? Thanks!

As soon as you figure it up, lets us know what it was. I hate electrical problems. When I come across one, I just send it to the electrical shop. I had an issue not to long ago and I was at the point of ripping all the wiring out of the truck in frustration...Good Luck

 

[larrydd999]

Bob, sorry to not get back quicker... I realize that the various accessories do not share a common ground - as noted by others, however since all of your issues were inside the car and the engine, etc., runs I suggested looking for a loose or missing body ground wire. Yes, by console I did mean dash (I've been spending too much time working on my boat...). One question - You said the remote does not work. Does it not work at all, or does it just not lock or unlock? The reason I ask is the possibility that the alarm module is somehow interfering with the accessories. I ended up unplugging mine after a leak in the left rear window caused it to fail in the alarming mode.
Keep digging - you'll find it and we'll all benefit!

 

[bob93explorer]

larry,

I'll make another attempt to find a bad ground wire around the kick panel, fuse box, etc.

We can live without the alarm system. Where is it located and how involved is it to disable it?

 

[bob93explorer]

Ok: got back into it this afternoon for a bit. Pulled the rear kick panel and viewed the modules there. One is obviously the keyless entry module - it has an antennae cable connected to it and I could feel it clicking when Jane hit the unlock button. It has broken off from the metal mount above it and has been bouncing/rattling around for who knows how long - years? There are 3 plugs from it. The first one I pulled killed the door unlock button that's good. There are two other modules in this location - what are they? The alarm module? What else?
Tomorrow I will pick up a panel button removal tool in town and take off the entire side panel left rear- around th window from rear corner to left rear door jamb. Maybe that bouncing around fatigued the wire bundle forward of that module or rubbing raw? Maybe the module internal circuit board crashed from the constant shock? full inspection tomorrow.
I spoke with a mechanic in town today said he has a partner that is aces with this kind of stuff and will look at it for $60.00 if I want him to. He agrees that the alarm system is the only common denominator among the affected items. Will report tomorrow. Any ideas?

 

[larrydd999]

Bob, one of the modules behind the left rear panel is for the 4x4 shift motor. The others you've already identified. My manuals don't identify which is which, but there are other threads on this site that have that information (which is how I found out about the shift motor module). You're obviously making progress, keep us informed.

 

[BKennedy]

Is your Explorer a Limited?

If so, it looks like interior fuse #6 powers your keyless entry module in acc/run.
Power distribution fuse #6 powers the keyless module at all times.

There should be a black ground wire on two out of the three plugs on the keyless entry module. Try jumping them to a new ground and see if that helps.

Try unplugging the anti-theft module and see if the keyless entry works without it.

Lastly, try unplugging both the anti-theft and the keyless entry modules and see if the problem goes away.

My Explorer is a XLT and only has the 4x4 module in the panel, along with the tow package relays.

Where do you live?