Clueless noob question

[Yobida]

Hi, everyone. I'm the owner of a '93 Explorer Sport that I've had for two years, driven a lot. Recently, I was unable to start it and had to have it towed home. I had several people tell me what it must be (different things, of course), so I've replaced the battery, relay, solenoid and starter and it still does exactly the same thing.

The easiest way to explain it is that the relay clicks, but doesn't turn over. I know, it's the battery is what everyone says first. Heard that one. It's not the battery because my horn also doesn't work... completely. There is a sound when I hit the horn, but it's a low toot, barely audible, so clearly there is something amiss in my electrical system. It does the same thing no matter what battery I use, so, I hope you'll forgive me repeating that it's not the battery. There are so many wires and cables that I don't know where to begin trying to isolate the problem.

I did disconnect the two wires from the starter on one end, and the positive terminal of the battery and relay harness at the other end, and tested for continuity, which I found, so I know that neither of those two wires is open. Also, that wouldn't have anything to do with the horn not getting enough power, so that was a wasted diagnostic, I think.

I would have searched for something, if I knew where to begin searching.

TIA for helpful souls.

PS: the title is true. I just recently began trying to work on this thing myself out of financial necessity. I'm learning, but I know next to nothing about automobiles. So far, my experience has been replacing the starter, starter solenoid, starter relay, fan clutch, and battery.

 

[safn1949]

Hi, everyone. I'm the owner of a '93 Explorer Sport that I've had for two years, driven a lot. Recently, I was unable to start it and had to have it towed home. I had several people tell me what it must be (different things, of course), so I've replaced the battery, relay, solenoid and starter and it still does exactly the same thing.

The easiest way to explain it is that the relay clicks, but doesn't turn over. I know, it's the battery is what everyone says first. Heard that one. It's not the battery because my horn also doesn't work... completely. There is a sound when I hit the horn, but it's a low toot, barely audible, so clearly there is something amiss in my electrical system. It does the same thing no matter what battery I use, so, I hope you'll forgive me repeating that it's not the battery. There are so many wires and cables that I don't know where to begin trying to isolate the problem.

I did disconnect the two wires from the starter on one end, and the positive terminal of the battery and relay harness at the other end, and tested for continuity, which I found, so I know that neither of those two wires is open. Also, that wouldn't have anything to do with the horn not getting enough power, so that was a wasted diagnostic, I think.

I would have searched for something, if I knew where to begin searching.

TIA for helpful souls.

PS: the title is true. I just recently began trying to work on this thing myself out of financial necessity. I'm learning, but I know next to nothing about automobiles. So far, my experience has been replacing the starter, starter solenoid, starter relay, fan clutch, and battery.

Battery cables...they are probably falling apart inside.

 

[Baddecision93]

Battery cables...they are probably falling apart inside.

I'll second that. Makes the most sense and is a relatively inexpensive thing to try.

 

[Yobida]

Well, I came back to let everyone know that I found the problem and fixed it! Thank you both for your prompt replies. I'm sure now the cables will need replacing completely at some point, but the main problem (extreme corrosion at the connector) has been repaired for the $3 cost of a new terminal connector. I noticed that all three of the main negative cables were starting to swell with internal corrosion, but the real problem was the lone, short wire that ran over to the wall for ground; its only remaining connection was a single strand of the stranded cable, the rest having completely corroded away. I hadn't closely examined it because it had been covered with electrical tape, but after cutting, stripping and reconnecting it, the car now starts fine. For economy's sake (both time and money), I just replaced the connector, knowing that at some point I will also have to replace the entire cable assembly.

Just a technical point I ought share: the ground wire gave me a beep with a continuity test, but that was only because that one lonely strand was giving it. However, that one lonely strand could not deliver enough power to service any but the smallest drains. That's why the relay would click and horn would make a soft hmpf, but the starter wouldn't operate nor the horn give its full blare.

Isn't learning new stuff fun? LOL

Thanks again.

 

[Roadrunner777]

The best test is voltage drop under load, but that can be another day and another problem, glad to hear you are set.

This reminds me of a problem I had years ago on a car with a mechanical clutch cable. I had recently changed the head gasket, and apparently coincidently, it started going through clutch cables every 2-3 weeks. Then one day, I was starting the car and noticed a whiff of smoke from the crack in the hood, and it was the clutch cable. It turns out I missed reconnecting the engine ground when I did the head gasket, and the clutch cable was now also the ground cable for the engine and starter.

I might have suggested a bad ground if you had not already found it. Well done!

 

[Yobida]

Thanks, Roadrunner. So if I may ask, how would I test a voltage drop under load in that situation? I have a digital multimeter.

 

[Roadrunner777]

Measure the voltage at the starter while it is cranking, for example. Compare that voltage to the voltage at the battery while cranking. The difference is what you are loosing in the cables.

Another great example that has been mentioned in other threads is the voltage loss from battery to headlights. Turn headlights on and measure at lamp terminals, compare to battery voltage. Say battery is 13.0V and voltage at headlight is 12.2V, that means the wires, fuses, switch, etc... are using almost a volt of energy that could have gone to your headlights and made them brighter. LMC truck makes a headlight harness that fixes this, btw, so the headlights get full battery voltage.

And, old school me, I actually prefer an analog voltmeter for this kind of thing because the voltage levels tend to be noisy (corrosion, etc...) and an analog needle smooths it out.

 

[SwaintaN]

Battery cables...they are probably falling apart inside.

This and the battery terminals is to be blamed on my problems, you have the same symptoms i had/have and thats what im doing, the biggest that is causing problems is my negative wires and terminal. i was driving down the road one day and it just stopped... and found out it was the negative terminal. thats what im gonna fix this next time to... waitting on good weather.. have a new negative terminal on its ways, 0ga ground and some wires to replace the rest... so yeah i agree its the cables... hopefully i get all mine done soon to.. good luck!