Dealing with an odd malfunction on my '86 Ranger:

1. THE BACK STORY A week ago, my Ranger was parked at work, nose out. A colleague backed into it hard enough to move it back 3-4 feet(rainy day, so a little slippery) No apparent damage, the Ranger started and ran fine.

2.THE PROBLEM A week later, after making a right turn leaving work, all sorts of gremlins: bogging down like a wind up toy that needed winding. Gauges acted odd: temp pinned out at top, gas 1/2 after having been filled in the morning. Goosing the accelerator kept it going, when I went to make the next turn, turn signals were weak, no flash. Babied her home, and upon opening the hood, found the battery loose in it's holder. My original working theory was the positive pole momentarily grounded on the fender.

3.TESTED SO FAR Alternator tested ok on bench at Autozone( I assume that includes the voltage regulator since it is mounted on the back) Swapped out and recharged the battery same old same old. Disconnected the NEG cable and checked from battery post to cable with test light, no joy. Tested the continuity of the 4 fusible links coming off the hot side of the starter relay(what I call the soleoid) all showed continuity. Removed and examined all the fuses in the fuse box, all appeared good.

4. IN CONCLUSION Having tried all the above, I throw myself on the mercy of the group, hoping one of you can suggest additional testing protocals to isolate the problem. I'm still suspicious of a short or bad ground. I have no idea if I'm conflating two unrelated evenst (the accident and the electrical problem)

 

You've done some good trouble shooting so far. I agree that it sounds like an electrical feed problem.

Have you done any wiggle tests on both battery cables on both ends of their runs???
Have you done any under load voltage drop tests on Both battery cables, or their connections on both ends????

I'm not clear on exactly what was done with the battery on the "swap out" part. Was the battery replaced with another one, or just removed, recharged & reinstalled????
Was the battery load tested after recharging????

If the original battery had been loose in its mounting for some time, it may have suffered some internal plate damage from shock & vibration of driving that's made it sensitive to movement/vibration & the thump it took in the parking lot may have been the finishing touch!!!!

So, you might try swapping in another battery to see if the problems stop, or during your wire wiggle tests try shaking or vibrating the battery while testing its output voltage, or with the lights on, to see if it'll act up with a voltage drop/light flicker.

More thoughts for consideration, let us know what you find.

 

Also, get a battery holder, they are a safety requirement in many areas. The idea is that int eh event of a collision, if the battery can move around, it is more prone to be able to short out and start a fire.

 

Sorry I wasn't clear: I put another battery in and charged it up. I've re tightened the battery mount too, Khan. Forgot to mention, KOEO test only yields code 11. I guess my next step in addition to the ones paw paw suggests is to remove fuses one at a time to see if I can isolate the failing circut.

 

OK good feedback, so you now have another battery in place & the problems persist, so we can move the battery itself lower down on the suspect list.

SO, maybe begin with a good wiggle test of the B+ & B- battery cables, alternator B+ cable to the under hood power distribution box & the battery to engine & body grounds & their connection fastners, looking for corrosion, loose, dirty, corroded connections, or broken wire strands.

If all that checks out ok, use your multimeter to perform under load voltage drop tests on those wires & across their connections.

 

Ok, will do. This is an '86, however, no power distribution box, only a fuse box in the cab and fusible links under the hood. Thanks for the suggestions.

 

Went out to futz with the Ranger some more. Now it won't start, only a faint click from the fuel pump relay. Now here's the kicker: if I let the key recoil from start to run, then pull the light **** to on, the solenoid starts clicking like crazy and the dash light flickers. Is this possibly a sign of a bad starter solenoid or a short in the headlight circuit? Please comment if you have any ideas. Thanks.

 

Have you performed any of the tests suggested in post #5???

 

Tried the wiggle test with no results. I'm gonna confess ignorance on the voltage drop test. Do I read the voltage to ground at the far end of the cable from the battery ? Is this with the engine running? I won't trouble you to explain it if you can direct me to a good technical post about the procedure.
Thanks.

 

OK, good idea to have first tried the wiggle test, as its quick & easy & often gives a result if the problem is a loose or broken connection.

So, read through this link about voltage drop testing & use the 20 volt DC range on your multimeter as outlined, to determine if your alternator, battery, battery cables, & their connections are electrically sound. Voltage Drop Testing

If all that checks out ok, look to a problem with the ignition switch, or power relay.
Power relays are a common problem part & can be tested by replacing them with another like relay from another circuit not needed to run the engine, like the AC power relay, if your in that test mode.

With the vintage on your ride, contacts & electrical B+ & B- connections are suspect, so pay close attention to how clean, bright & tight those connections are. We only have 12 volts DC to work with, so any loose, rusty, corroded, worn contacts will cause mischief & right now it sounds like you may have a basic B+ power power feed problem from the battery to the fuse panel, or a ground problem between the battery, to engine, or body, so check those first before suspecting the ignition switch.

An electrical connection that carries a lot of amperage, like the battery cables & their connections on both ends, will be warm or hot at the problem spot, if you've recently cranked the engine, or had the head lights on to load that circuit & electrical resistance from corrosion, rust, broken wire strands, or a loose connection is too high on those circuits wiring or connections.. You'll also measure voltage drop across the faulty connection.

If you come to suspect a fualty wire or connection, try a parallel connection along that wire, or across its connections, with a good quality large wire gauge, say 4 gauge stranded copper jumper cable, along the suspect wire & see if you get positive results. The parallel jumper cable, with good clean tight connections on both ends, gives a parallel path for electron flow & if its resistance is low & you've made good clean contacts on both ends, the circuit should wake up & then you'll know that the wire & or its connections you've just applied the parallel connection to, is the problem, so you'll have narrowed your search to three things, the wire itself, or its connections on either end of its run.

Some thoughts to get you started, let us know how the trouble shoot goes.

 

Just for fun, I hooked up the remote start switch from the stud on the solenoid
to B+. The starter cranked strong and immediately. Does this shift suspicion away from the primary B+ B- cables and their connections? The fuel pump is not energizing when the key is turned.

 

Yes, if it cranks strong, it sounds like the battery, cables & their connections between them & the starter motor are ok.

If you turn the blower motor on high speed & the head lights on, are the head lights bright????

If you can't hear the fuel pump run, & don't have a multimeter to check voltage to it, look to its fuse & if its ok, look to a relay, or wiring problem to the pump, so do a wiggle test on the wiring to the pump & thump the relay & pump to see if it'll wake up & run.

 

Was messing with the ignition switch: making sure I had voltage there (I did) and found I could crank the starter in a smallish "window" on the switch and it started. Now here's the kicker: all gauges showed nominal. Put it in gear and drove away, gauges started going gaga. Stopped, put it in park, all gauges crept back to normal. Put it in gear, gaga. I wonder if something is amiss in the transmission. Gonna crawl under it tomorrow and look over the neutral interlock switch. Gonna brush up the -B ground while down there too.

 

Sounds like you have an ignition switch contact problem.

 

Two thoughts come to mind. I had a 'slowly dying, wipers go slower and slower, lights dimmer and dimmer, radio turned itself off .. engine ran very poorly with little power, barely made it up a hill before dying and coasting into a gas station.' I figured big time problem. Nope, was the large cable on the battery itself. Somehow had gotten loose. Then repeated the wiper thing, and I checked before it got worse. It was the large red cable from the "+" to the relay post. It had worked loose. Then I checked alternator output. Checked battery voltage, 12.75 or so. Started the truck, and measured across the battery. Was below 13v. Should be above 13, closer to 14 from what I read. Running voltage was less than before it started. Drove to my destination and back, and re-checked. Voltage was 14.xx ... I wiggled the wires on the regulator and was able to reproduce the change in alternator output.



Second, the actual ignition switch on the steering column could be coming apart. It has pot metal 'crimps' holding it together. Over time, they relax, and on my truck, the tension or twist of the wires leading to the connector to the ignition switch pulled on the switch such that it was coming apart. The symptom was that it would not stay running unless the key was turned very slightly towards the 'start' position, at which time it ran fine. New switch was the final corrective action, with an interim re-crimp that lasted until I could get a switch.

Quote:
"Now here's the kicker: if I let the key recoil from start to run, then pull the light **** to on, the solenoid starts clicking like crazy and the dash light flickers."

The headlights, when turned on, formed the other 'half' of your circuit, using the filaments, wires and switch to conduct the juice needed to operate the relay internal winding, but not enough to operate the starter motor. When the relay closed, it used more battery power, and that dropped the relay power enough that the internal spring opened the relay against the pull of the windings. You may have a bad or missing ground. Given this all started when you got bumped, check the underhood wire & grounds as Pawpaw suggested. Thing is, they can show good conduction, but when you go to throw some big amps, such as starter motor use, they don't let enough through due to corrosion or bad conduction.
One other thing, I had to replace the starter relay soon after all the above, maybe, or I might have swapped it into my wifes car. Either way, it was disassembled, and put back together and works fine now. That may be why the large post wire got loose... Hmmm
tom