Explorer lost all power, then came back

[floatingpig]

Hi all,
I have a 1997 Explorer 4.0l SOHC with roughly 147,700 miles. I purchased it back in February from the second owner, the car was always garaged and is close to perfect. Never thought I would have any trouble with it, until last night. I got home after driving about 50 miles, turned the key off and everything went black. Autolamp didn't stay on, no door lights or reading lights, no power locks, nothing; just like the battery had been disconnected. I put the key in and went to start it, nothing. I took the key out, put it back in, ignition turned on and car started right up. (Of course, the radio lost all of its settings and the clock).

Has anyone else experienced this? What should I look at? What problems should I prepare for that this is warning me about. I'm enough of an amateur mechanic that I could probably fix this, I just need a little help identifying the problem.

Thanks in advance for any input! I really appreciate it!

 

[koda2000]

check/clean/tighten your battery terminals, connections and clamps. they're probably loose or dirty.

this should be part of your regular maintenance routine, just like changing oil and filters.

 

[floatingpig]

I should probably have mentioned this in my first post. The battery terminals are new and tight. I replaced them both when I hooked up two small amps, one for speakers and the other for subwoofer.

 

[koda2000]

I should probably have mentioned this in my first post. The battery terminals are new and tight. I replaced them both when I hooked up two small amps, one for speakers and the other for subwoofer.

what about cleaning the battery posts? i've had this happen probably half a dozen times over the years and it's always been the battery posts/terminals.

 

[floatingpig]

I haven't left for work yet, fingers crossed that it starts! I will check out the terminals when I get home from work (should I even be able to leave, haha). I'm not sure how old the battery is, and it's a Les Shwab battery, so I've always questioned its quality. But the Explorer has never failed me

 

[koda2000]

I haven't left for work yet, fingers crossed that it starts! I will check out the terminals when I get home from work (should I even be able to leave, haha). I'm not sure how old the battery is, and it's a Les Shwab battery, so I've always questioned its quality. But the Explorer has never failed me

it really helps to have/use one of the battery terminal & post cleaning tools. one end has a hole with an internal brush and the other end has a conical brush. i've had battery posts that looked perfectly clean, but were dirty enough to not make contact.

if it happens again before you get a change to clean then, just carry a small hammer or wrench to give the terminals a smack (not too hard) to reestablish contact.

 

[floatingpig]

I have to stop by Autozone today anyway...I will pick up a terminal brush. Maybe I should have them test my battery/alternator as well. I'll let you know how it goes!

 

[koda2000]

I have to stop by Autozone today anyway...I will pick up a terminal brush. Maybe I should have them test my battery/alternator as well. I'll let you know how it goes!

well, the tests are free, but you have a connection problem not a battery or alternator problem. 12 volts doesn't go to zero and then decide to just come back again later.

 

[RomeovilleIL]

Noted that you just replaced the connectors. Very likely related to the issue. Recommend you go back and re-do the connection between cable and terminal. Also since you would have been moving around the cables in the process of doing that reoplacement you might very well have created a break somewhere within a corroded old cable. I chased this gremlin myself on a dodge for a couple months before I finally pulled the cables completely off only to find the negative was basically green powder under the insulation.

 

[koda2000]

Noted that you just replaced the connectors. Very likely related to the issue. Recommend you go back and re-do the connection between cable and terminal. Also since you would have been moving around the cables in the process of doing that reoplacement you might very well have created a break somewhere within a corroded old cable. I chased this gremlin myself on a dodge for a couple months before I finally pulled the cables completely off only to find the negative was basically green powder under the insulation.

good point. if the cables look lumpy, replace them. plus more often than not, i find the last thing i messed with is the last thing i messed up...

 

[floatingpig]

I replaced both battery terminals and it seems like it starts up easier now, but that could just be my imagination.

I've noticed something else, and I think it has done this since I purchased the car, but it doesn't seem normal. While the defrost or air conditioning is running, the A/C compressor clicks on and off excessively, but the A/C is cold and works great. I've never seen a car do this. When it clicks on and off the RPMs drop from about 900 to 450 and the lights dim quite a bit. I checked the voltage of the battery when the car does this and it goes from about 14v down to 12.5-12.8v. I have the standard heater/AC system, not the digital climate control.

 

[koda2000]

what do you consider excessive cycling of the compressor? depending on outside temp, it might cycle every 8-10 secs or so. if more frequently than that, get your refrigerant pressure checked.

the idle should kick up slightly when the a/c clutch engages. if normal idle is around 850-900 rpm, it might increase to 950-1000 when the a/c clutch kicks in. 14+ volts is about normal when idling with accessories off. your low idle when the a/c clutch is engaged is probably what's dropping the voltage to 12.5-12.8 volts. the pcm should increase the idle to make up for the drag of the a/c compressor.

your battery connections look good. did you notice if there was any red/black paint on the inside of those terminals?

 

[floatingpig]

I would say that the idle drops down to below 500 when the compressor kicks on, then goes back to normal when the compressor shuts off. The cycling happens every 5 seconds, just strange that I have never seen a car do that except for Explorers. My 98 Mountaineer 5.0 that I had a few years ago never did that. Is it a problem that the idle drops instead of increases? It is annoying, but I don't want to create a problem when one doesn't exist.

 

[koda2000]

I would say that the idle drops down to below 500 when the compressor kicks on, then goes back to normal when the compressor shuts off. The cycling happens every 5 seconds, just strange that I have never seen a car do that except for Explorers. My 98 Mountaineer 5.0 that I had a few years ago never did that. Is it a problem that the idle drops instead of increases? It is annoying, but I don't want to create a problem when one doesn't exist.

all 4 of my Explorers/Mountaineers cycle the a/c compressor about every 8 secs or so and the a/c in all 4 blow ice cold. but again, it has to do with the outside temp. your refrigerant might be a little low. the only way to know is to get it checked with a gauge set. the clicking noise you hear depends on the type of a/c clutch you have. in any advent, your idle should not be dropping that low.