1994 Ranger no charge

izzo · Dec 2, 2016

Ok. I will start from the top

I recently traded something for a 1994 ford ranger. It's the 3.0 with automatic. Standard cab/bed.

The guy told me it wasn't charging and that's all he knew. He said the gauges didn't work either. But he managed to get them working. He said he pulled the cluster out and did something or other and they work. But not all of them do.

I looked at the gauge cluster and surround with a flash light. I see NO battery light. Just the stock volt gauge. It reads nothing at all as if it's not hooked up.

So. The temp, oil pressure, and fuel gauge do work. The voltage gauge reads nothing. I also noticed, when i turn the key on. None of the warning lights come on like other cars do before you start it. When in the RUN position, i can hear the fuel pump working. The heater/wipers come on like they should. The truck starts right up. But it's not charging.

I have checked all the fuses, replaced some of them if they even looked bad. I also did a continuity test on them. They came back good. I tested the trigger wire for the alternator. It read .5 of a volt. I thought it had to have 12 volts all the time when in the RUN position to tell it to charge. Someone else told me that it only gets a jolt when in the start position? Can anyone confirm this?

Next I tested the alternator wire that goes from the battery post, to the starter solenoid on the firewall. my multi-meter reads .5 just touching the leads, and read the same when testing the wire. So I'm assuming the wire is good and in the fusible link is good.

I don't want to pull the alternator just yet. It could be bad, but I don't think it is. The volt gauge not reading, and the dash lights not coming on before it starts almost sounds like an ignition switch?

I don't know what to test next. I am mechanically inclined. Just not good with wires. I have built many datsuns and can do that all day. But this is new to me.

Anyone help me out here? What wires should I test with the key on/off to see if power is on where it should be, like on the ignition switch wires? Also any other wires i should test for continuity?

Time sensitive getting this truck up and running. Thank you!

ericbphoto · Dec 2, 2016

You need to have 12 volts going to the alternator to energize the field (through the regulator). You should also have 12 volts at each place you check coming from the battery to the alternator.

I'm not at a good place to copy and paste a bunch of info for you right now. But....

There are some good electrical drawings I. The tech articles on this site.

Also, RonD does a really great writeup of troubleshooting the charging circuit. There are a few threads in various places on this forum where he has given that info. Just do a search for charging problems or battery problems. Or search for threads with his username.

If you can't find them and he doesn't chime in here, I'll help you find them tomorrow.

Sent from my SM-G920V using Tapatalk

RonD · Dec 2, 2016

Welcome to TRS

You do have a Battery Light, and thats the green wire that needs 12volts to Turn it ON the alternator.
Battery Light is also called Charge Indicator, just a 12v light bulb.

Battery----50amp fuse----Ignition switch-----Battery Light Bulb--------(green wire)--------Alternator(3 wire connector)

When you turn on the key 12volts goes to the Battery light bulb and then thru it to the Alternator.
When alternator is not spinning(generating power) it is a Ground.
So Battery Light Bulb has 12volts on one side and a Ground(non-spinning alternator) on the other side, so Battery Light Bulb Lights up.
When you start the engine, the alternator starts generating power.
Usually 13.5 to 14.5volts
So Battery Light Bulb now has 13.5volts on one side and 13.5volts on the other side, no Ground, so battery light bulb goes off.

If alternator stops working then it becomes a Ground again and Battery Light comes on again.
If alternator is generating less than 12volts then Battery Light will flicker, because battery is 12volts and alternator is say 10volts so partial Ground(0volts)

As eric said the yellow alternator wire and B+(larger wire on the back of alternator) need to have 12volts all the time, they are hooked directly to the battery via fuses
Green wire is the only one that is ON/OFF with the key.
An alternator doesn't "create power" it multiplies it, so you have to give it voltage FIRST then it can make more as ir spins, that is what the Green wire does, it is the "starting" voltage for the alternator.
If you give an alternator "starting" voltage all the time then it will drain the battery, so there has to be an ON/OFF switch for the alternator.

Because the ON/OFF is important the Battery Light Bulb also has a Resistor By-Pass, it has higher resistance than the bulb, so bulb carries the 12volts and lights up if alternator is a ground.
But is bulb burns out.........alternator would stay OFF, possibly stranding you.
So if bulb burns out the resistor takes over and passes the 12volts

Here is the 1994 instrument cluster wiring
It reads like you do have some wiring issues, could be ignition switch under steering column or in the cab fuse panel
The dash Volt Meter is just hooked to dash power and a ground, it isn't part of charging circuit, so if it is 0volts then dash is not getting power

izzo · Dec 3, 2016

RonD said:
Welcome to TRS

You do have a Battery Light, and thats the green wire that needs 12volts to Turn it ON the alternator.
Battery Light is also called Charge Indicator, just a 12v light bulb.

Battery----50amp fuse----Ignition switch-----Battery Light Bulb--------(green wire)--------Alternator(3 wire connector)

When you turn on the key 12volts goes to the Battery light bulb and then thru it to the Alternator.
When alternator is not spinning(generating power) it is a Ground.
So Battery Light Bulb has 12volts on one side and a Ground(non-spinning alternator) on the other side, so Battery Light Bulb Lights up.
When you start the engine, the alternator starts generating power.
Usually 13.5 to 14.5volts
So Battery Light Bulb now has 13.5volts on one side and 13.5volts on the other side, no Ground, so battery light bulb goes off.

If alternator stops working then it becomes a Ground again and Battery Light comes on again.
If alternator is generating less than 12volts then Battery Light will flicker, because battery is 12volts and alternator is say 10volts so partial Ground(0volts)

As eric said the yellow alternator wire and B+(larger wire on the back of alternator) need to have 12volts all the time, they are hooked directly to the battery via fuses
Green wire is the only one that is ON/OFF with the key.
An alternator doesn't "create power" it multiplies it, so you have to give it voltage FIRST then it can make more as ir spins, that is what the Green wire does, it is the "starting" voltage for the alternator.
If you give an alternator "starting" voltage all the time then it will drain the battery, so there has to be an ON/OFF switch for the alternator.

Because the ON/OFF is important the Battery Light Bulb also has a Resistor By-Pass, it has higher resistance than the bulb, so bulb carries the 12volts and lights up if alternator is a ground.
But is bulb burns out.........alternator would stay OFF, possibly stranding you.
So if bulb burns out the resistor takes over and passes the 12volts

Here is the 1994 instrument cluster wiring
It reads like you do have some wiring issues, could be ignition switch under steering column or in the cab fuse panel
The dash Volt Meter is just hooked to dash power and a ground, it isn't part of charging circuit, so if it is 0 volts then dash is not getting power

Ron,

Thank you. I get how the light works. The same deal for the old datsuns

I am not familiar with fords sadly.

I looked with a flash light, and didn't see any charge/battery light anywhere on the dash. I found an ABS light, 4x4 light (this is a 2wd) and so on. But didn't see a charge light anywhere. Given that it has the resistor, it should still charge even if the light is burned out. I don't see any messed up wires, broken wires, cooked wires, cut wires. It all looks OK. It does have an aftermarket stereo. But looks like it was installed professionally. It comes on/off with they key as it should.

none of the warning lights come on when the key hits the RUN position before starting it.

So from the diagram, I should hit the key to the run position, then test the GRY/YEL wire coming off the ignition switch correct? And that should have 12V. I was pretty sure the light green/red stripe wire should have 12v all the time when on/running.

So tomorrow I will test the Grey/yellow wire coming off the ign switch. I pull the clam shell off the column today. There is a bundle of wires going into the turn signal stock. Is that it? Or is it further down on the steering column? I got mixed information reading on the internet.

Also, i read somewhere that you could "jump" that green/red stripe wire with 12V to trick it, and see if it charges then.

To sum up the questions,
I need to test the Grey/Yellow coming off the IGN switch with the key on the Run position?
Is it down towards the bottom of the column?
What other wires should I test for power, or continuity?
Should I pull the gauge cluster out and take a look at all that? Double check the lights or?

Thank you,

Tim

ericbphoto · Dec 3, 2016

I would expect your instrument cluster to be very similar to mine, if not identical. Mine is a '93. On the lower left, your indicator lights should be (from left to right)

left turn
check engine
low oil
Battery

I'm just looking at a photo of the back of my cluster. But I'm sure I read that right. You may have extra warning lights that don't do anything on your truck. They just used a standard cluster for several models. Mine has a "anti-theft" light. But I don't know of any anti theft devices in my truck other than door locks steering lock and a dog in the passenger seat.

I believe you will find 3 electrical harness connectors on the steering column. Two of them are right next to each other very high on the column and the other is further down, closer to the dash. I THINK that one is the key switch connector. You should be able to see what is attached to the key switch and figure out which connector it is.

RonD · Dec 3, 2016

Yes, if you jump 12volts from battery to Green wire on alternator it should start charging, battery voltage will read 12volts then jump up to 14volts when Green wire is powered up, you can then remove that jumper wire and alternator will continue to work.

But as said, if green wire has power all the time it will drain the battery when engine is off.

An alternator generates power by multiplying it.
Voltage regulator sends power to the Rotor, 7 to 9 volts, with this voltage as the rotor spins it creates "waves" of magnetism in the 3 Fields in the case of the alternator.
These waves create AC voltage in each field, each field has 2 diodes that change this AC voltage to DC Voltage.
The 7 to 9volts DC at the rotor multiply to 13 to 15 volts DC out of B+ alternator

That 7 to 9 volts comes from the Green wire, to start things up, once started it isn't needed.
If you send the 7 to 9 volts to rotor all the time, engine off, then rotor acts like an electric motor, a weak electric motor, lol, it will try to spin the fan belt, which of course it can't, so battery drains.

1 Wire alternators use an internal RPM switch, when alternator RPMs get to and above 2,100rpms(3 times engine RPMs) the switch closes and send the 7 to 9 volts to rotor and alternator starts generating the 13 to 15 volts.
So they only need the 1 wire connected to the battery 24/7(all the time)
When RPMs are below 2,100 then switch opens and no drain on battery
These do work fine but you do lose Battery Light warning system
But a good accurate digital volt meter added to the dash will give you the "heads up" if voltage drops below 13volts with engine running.
These are very popular with custom builds

Not a great change for existing systems

izzo · Dec 3, 2016

You guys are a wealth of information and knowledge lol. Very good and cool info Ron.

Eric, I went and double checked. Sure as sh... Battery light, left side of wheel, closest to it!

But none of them light up when the key is on. Do I need to unbolt the 2 bolts holding the wheel to the column to drop it down and gain access to the ign switch? From what i read that seems to be the ticket.

It looks like i would have to do that anyways to get the cluster out. the shifter is in the way. I can't see how to get the dash apart at the moment. May have to google around some more/youtube some videos to see whats gonig on there.

ericbphoto · Dec 3, 2016

Not sure about lowering the column to get the cluster out. I have a manual transmission. On the Yukon I had with automatic trans, I had to pull the shift lever down in to 1st gear to get the cluster past the lever. Maybe you could try that trick.

You may also want to stick your hand up behind the cluster and push the electrical connectors into the cluster to make sure one of them isn't loose.

For me, the worst parts of removing the cluster are;
a. removing the trim bezel without breaking it
b. getting the %$^#@$ speedometer cable loose - there is a way to squeeze it to release the locking tabs. But my hands have trouble getting up there and doing it.

izzo · Dec 3, 2016

Ha yeah i broke a few tabs on the plastic surround. Oh well.

Gauge cluster out. I checked the lights, they are all good. I cleaned the brass strips with a pencil eraser. It all looks fine on the back of the cluster. I will have to lower the column in order to get to the ignition switch. IDK if i have the correct bit to get it undone. I think it's like a T30 or something. I don't have any star wrenches that size. I may have one, but the chances of it being the right size are pretty slim!

I need to test that Grey with yellow stripe yet with the key on.

So to verify. The power wire that goes to the alternator. That should have 12V all the time while it's running telling it to charge correct? And it's off when the key is off for obvious reasons.

RonD · Dec 3, 2016

Ignition switch should be under steering column above brake pedal area.
Google: ranger ignition switch replacement

This is not the ignition Key lock, that just slides a rod that moves the ignition switch

Green wire will show 12volts when key is on, 14volts(approx) with engine running, no volts with key off.

izzo · Dec 3, 2016

So!!!!

I pulled the gauge cluster out. Cleaned up all the connections. I used a 9v square battery to test all the gauges, and lights. They all work.

Put it back in and what do you know. Volt gauge works, all the warning lights come on, and go off when its started. It's charging around 14.5 volts! The turn signals don't flash. But they do come on when you use the turn signal. It just sticks. the hazards flash, but not the signals. I will worry about that another time. For now, I'm happy its all working again.

It's been sitting a few years. I am adding a fuel treatment to it, filling with premium. Changing the oil, and adding some oil treatment to it. It almost sounds like one of the lifters is a little sticky. Hopefully that clears itself up. I will put it all back together tomorrow.

Thanks for all the help. I will stick around the site and do some reading on tips, tricks etc for the rangers. I will start a thread sometime with some pictures etc.

I am usually on my own forum. I have had over 40 datsuns and love them. I own a forum with some members on it, and a facebook page with thousands of members here in the Nw

Thanks again.

RonD · Dec 3, 2016

Good Work

Thanks for posting the update

Good page here to Bookmark: http://www.therangerstation.com/tech_library/index.shtml

Lots of "been there done that" articles by members
Check out electric diagrams for turn signal info

Yes, could be lifters but Ford fuel injectors are not quiet, they can "tick" pretty loud, lol.

ericbphoto · Dec 3, 2016

Always good to hear another success story. Congratulations on getting it working.

Sent from my SM-G920V using Tapatalk

izzo · Dec 4, 2016

Thank you!

I suspect that since there was a bad connection on the gauges. One the battery light wasn't working, and two. Since it wasn't working, the little resistor wasn't able to work as well. Resulting in a no charge.

The ranger has sat for 3-4 years. It starts up just fine. But it is a bit gutless. The gas is probably bad. I added some lucas fuel treatment. Supposed to help with old gas, clean injectors etc. Thinking of doing some SeaFoam treatment as well.

I will be doing a tune up. Plugs, wires etc. But want to run some treatment thru it. Any suggestions for a truck thats sat for a few years? On my datsuns. I change all the fluids, check the belts, run some gas treatment product thru it with premium gas. Also usually run some oil treatment with a fresh oil change. Slick50 etc.

What do you guys do/suggest for the fords?

mrjeep44s · Dec 4, 2016

Had the same problem. My battery gauge was bad. replaced it with a used one and now all works as it should. hope this helps.

1994 Ranger no charge

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