Over the past week my truck cranked slowly on the cooler morning we've had after sitting a couple days. Sunday morning, it wouldn't crank at first and the dash lights were coming on and off and there was some clicking going on when I put the key in the "Wait to Start" position. I checked the battery voltage it measured 12.3. I checked the head lights and they worked. So I tried to start again and same thing happened, lights flashing various clicks hapening somewhere. Then I turned the headlights on expecting all the dash lights to go out due to the extra load on a possible weak battery. But instead, the dash lights went to there normal starting state and it cranked. Slowly, but it still cranked. Drove it the rest of the day with no problem. I'm thinking now it may be a bad battery connection(s), but they seem tight.

The only other thing is I have used the truck a couple times over the past month to jump start the 96 Explorer since the Explorer has developed a short somewhere that drains the battery dead if you let it sit for a week or so.

So I have a couple questions here.
1) Could I have damaged anything jump starting the Explorer?
2) Suggestions for testing the battery connection.
3) Ideas or links to web sites for technical assistance on my Explorer issue.

 

I would go to a parts store, for a couple of bucks you can pick up a batt terminal cleaner, it is a R2-D2 looking thing with wire brushes for cleaning terminals, clean em up and see how it works. It is possible to fry your voltage regulator when jumping a vehicle, but you would get a Battery light on the dash if that was to happen.

 

Did you get the 12.3V reading with no load on the battery? 12.3V is actually
a fairly discharged voltage for a car battery. Roughly this is the state of charge for car batteries:

12.6-13 =100% 12.45 = 75% 12.25 = 50% 12.06 = 25%

I would start by cleaning the terminals and retighten them. Then I would check the other ends of the cables especially the grounds. Then check the electrolyte levels in the batteries. Charge the batteries with a charger if possible and then test the alternator with your multimeter. Running at 1500-1800 rpm should read around 14.4V. Then turn on headlights and fan blower to high and see if it holds close to that or drops significantly.

When the alternators go on these trucks, there is usually little or no warning. Both times when my stock ones failed, I got no warning light or gauge movement at all. One moment seemed fine and then... bam.

If everything is clean, tight and tests okay, then I'd move on to other things like GP relays etc.

Keep us posted and good luck. Electrical issues are a pain in the a$$, but methodical troubleshooting will find 'em. Be thorough and you'll find it.

Austin

 

Mine has done this a few times. When i crank mine i can hear a relay clicking under the dash somewhere. If i hear this and i open the hood and play around with the positive terminal on the passenger side and get back in it fires right up. I have a new connector as the stock one is smashed as tight as it will go and is loose. I just havn't put it on (lazy) lol.