HELP - Bronco won't start and I'm terrible with electrical issues

[Chicago71Bronco]

Let me start out by saying thank you in advance for your help. Also, let me preface that I AM BY NO MEANS GOOD WITH ELECTRICAL STUFF so if I sound like an idiot that's why.

Ok, so here goes..... I just spent a month doing everything I could think of to this truck and I hopped in it today to go for a cruise and.....click. The motor wouldn't even turn over - all I got was a loud click. I was kind of puzzled as this has never happened before. I checked the lights and stereo and everything worked just fine.

The battery is only a few weeks old, so Im thinking that cant be it.

I started looked at the starter solenoid that's mounted right behind the battery (I think thats what its called - its the thing that goes Click). All of the connections seem to be tight and wires are in good condition, but the solenoid is probably pretty old.

My first thought was to go buy a new one for $49, take pictures of how it's wired now, and rip out the old one. Then I'll put the wires back in the same spot on the new one and see if that works. FYI- other than the positive battery cable I have no idea what all the other wires are for.

Is this a good first step in trying to diagnose this or should I be doing something else? Kind of flying blind here.

Thanks,
Adam

 

[Rickb1b]

OK First question, do you have a volt meter or test light. When trouble-shooting electrical problems and you don't know the source of the problem, it's best to start at the source and check the voltage from the beginning to end.

I your case start by checking the voltage across the battery. Best to put a charger on it for a few hours just to make sure that's not the problem. Next is the starter solenoid. If it's clicking it's getting power (maybe not enough, that's why you need to ensure the battery is fully charged). Have someone turn the key and check the voltage on the other side of the solenoid. If it has power, next is the connection to the starter. Once again have someone turn the key and check the voltage at the connection to the starter. If it has power, then the problem is with the starter or the ground of the starter.

Just in case you don't know, when checking electrical stuff, you somehow connect the black wire of the volt meter to a solid ground on your truck. I usually connect to the frame. Then use the red wire to check the voltage at the key points I mentioned above.

Basically just ground your volt meter and use the red line to check the voltage along the path of electricity. Start at the battery red terminal and with the key in the start position follow the wires all the way to the starter, checking the reading at every connection. When you find a spot with a low reading, your problem is the first connection upstream. Since your solenoid is clicking, for now you only need to check the big wires. The little ones are doing their job.

This should get you started. Lets us know if you have good readings (12v) at all these points.

PS; another really quick check is to turn on all the lights and radio, then try to start it while watching the headlights. If they dim, your problem is a weak battery. If they don't, it's a poor connection between the starter and battery, bad solenoid or starter. Then you will use the above procedure.

 

[Chicago71Bronco]

Wow thanks for such a great response. That all seems to make perfect sense. I'll buy a volt meter today and give it a shot.

One question - when you say to "start by checking the voltage across the battery" does this mean touching the positive of the volt meter to the positive battery terminal and neg of the volt meter to the neg battery terminal at the same time?

Thanks

 

[Ranchtruck]

Do you have jumper cables?
Put the truck in park or neutral with the e-brake on and the wheels chocked.
Use one of the jumper cables to bypass the starter solenoid, so clamp it to both big terminals on the solenoid. If the engine cranks you know the solenoid is the culprit.

 

[70_Steve]

One question - when you say to "start by checking the voltage across the battery" does this mean touching the positive of the volt meter to the positive battery terminal and neg of the volt meter to the neg battery terminal at the same time?

Yes. Red positive lead of voltmeter to + side of battery, and black negative voltmeter lead to the - side of the battery. Voltmeters are pretty cheap now. Saw one on sale at Harbor Freight for $3.99 or so...

Make sure you put the voltmeter on an appropriate scale. And make sure it's set for DC, not AC. Should have something like a 20 Vdc scale. A fully charged battery should read somewhere around 12.5 volts.

The solenoid operation is pretty simple. It's just a relay. The coil goes between the S terminal and the mounting flange, screwed to the fenderwell. The S terminal is one of the two little terminals, next to the big BAT+ terminal. The positive battery cable should be connected to the BAT+ terminal. The other big terminal, on the other side of the solenoid is the STA terminal and should have another big cable attached to it. That cable goes to the STArter...

When you turn the key to START, the ignition switch puts power to the little S terminal which energizes the coil and should connect the BAT+ to the STA terminals to put power to the starter. The "click" you hear is the coil energizing, and pulling a set of contacts together.

When the battery is not at full charge there can be enough voltage to pull in the solenoid and make the "click", but not enough power to turn the starter and engine over.

Another indicator would be to turn on your headlights, then try to start the eigine, assuming the Bronco is someplace you can see the output of the headlights. If the headlights go out completely, then the battery is suspect. Either a low charge, or defective to the point of failing a load test.

 

[bronco loco]

This will really help you to understand basic electronic troubleshooting on the bronco.
http://classicbroncos.com/tech/basic-vehicle-electrical-diagnosis

 

[DirtDonk]

How old is the starter itself?
Reason I ask is that there is one other semi-common issue that can afflict older starters on just about any vehicle. It could just be old and "stuck".
You can easily verify this by giving the starter motor a quick smack with something heavy like a hammer or the heavy handle of a screwdriver or whatever. When access is limited, I've even had good luck with a long screwdriver on the starter and hitting the handle with the hammer.
Just a good shock or two should be all that's needed to free the starter up.
If that's the actual issue, and the engine starts right up after that, then you know your starter motor is just getting old and needs to be replaced some time soon.

That's just a quick-n-easy test to do sometimes. Otherwise, everything the others have said is the way to go. Good descriptions to start off your new life as an electrical guru!

Paul

 

[Chicago71Bronco]

Thanks for all the great advice. Cant wait to get off work and start messing with it.

First I'm going to take DirtDogs advice and just hit it with a hammer - thats more my style.

If that doesn't work I'll try bypassing the solenoid with jumper cables - trickery is also my style.

If these don't work I guess I'll actually have to do it the right way which, thanks to all of your feedback, I now know how to do.

 

[Rickb1b]

All of the above is good advice. I know it's been mentioned twice, but when I have your situation, first thing I do is turn on all the electrical stuff, then attempt to start it. Watch the headlights, if they go out or dim a lot, you have a weak battery. If head light stays bright, you have a bad connection.

 

[Chicago71Bronco]

Well is everyone ready for a good laugh at my expense?

Ok so I tested the battery and the battery is A-okay. So on to the solenoid...but first I decided to remove the big clunky air filter to give myself some room to work. While I was doing this I dropped a washer straight down the carb.

I spent the next 2 hours going to the hardware store to get a magnet probe and trying to fish it out. That didn't work because it didn't go straight down the barrel but down the side. Next I tried a skewer with gum on it and that didn't work either. Looks like the carb is coming off tomorrow and I guess as long as I'm doing that I may as well just buy new carb.

Aren't Broncos fun?

 

[Chicago71Bronco]

Update: after a half hour sitting with my right knee on the drivers side wheel well, left knee on the valve cover and shins on the radiator sweating bullets I was finally able to fish the washer out I the carb with a piece of wire.

Then changed out the solenoid and +battery cable and she started right up!!

Thanks for all of the help everyone