replace voltage regulator without removing alternator? | Ford Escort Owners Association (FEOA)

replace voltage regulator without removing alternator?

Discussion in 'General Discussion' started by gimpel, Jul 25, 2019.

  1. gimpel

    gimpel FEOA Member

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    Greetings...

    I had to jumpstart my 'new' 1999 Escort SE (only bought it on Sat) four times Tues afternoon, and in morning to get to work and home again yesterday. Voltage on battery measured 12.08 (very low) charged batt overnight and now where it should be at 12.8V. Running fine now, and I hope by not using A/C or night driving I will be able to get around until I can fix prob...
    OReilly did test, said voltage regulator failed so I need a new alternator... (of course they went for the high dollar item...) he asks, you want to order the alternator? i told him, not yet...
    I find estimates for a shop to replace alternator up to 500$. I have replaced alternators in the past, and have encountered problems with 'tight fit' to get replacement to go into place... also have to remove serpentine belt... and mebe remove fender splash guard and disturb A/C hoses and other stuff...

    no noises from bearings in alternator (which may be original... car has only 81k miles, and Motorcraft name on voltage regulator.) why replace alternator if it is the voltage regulator (cost 20$ on ebay) which failed?

    I have seen a number of posts on internet that the voltage regulator can be replaced without removing the alternator, but info is not complete or consistent... (four screw hold voltage reg in place, hold brushes in with paper clip (?!), or brushes come with)...

    1. can I get replacement Motorcraft voltage regulator?

    2. And, the access is really tight in the engine compartment to reach the screws. maybe I should buy Allen head or star head sockets to fit my 1/4" drive socket wrench?

    3. One other thing... how can I test myself (with voltmeter) to confirm voltage regulator is bad, and alternator is good?

    any response will be most welcome... if you do not have answer, perhaps you can point me toward them...

    regards...
  2. millball

    millball FEOA Donator

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    I have replaced regulators and brushes without removing the alternator on both 2nd and 3rd gen cars. 1.9 and 2.0SEFI engines. I bought generic brush cassettes and regulators from Ebay with good results. Everything really depends on whether or not the slip rings are still in decent shape.
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  3. gimpel

    gimpel FEOA Member

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    thanks...
  4. denisond3

    denisond3 Moderator Staff Member

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    I have run into the problem that the torx head screws holding the volt reg to the body of the alternator are too tight, or corroded into place - and the heads snapped off when I was unscrewing them.
    This area under the hood would be slightly easier to work in for the alternator, if you undo the four small bolts holding the two braces for the upper side of the radiator in place. This will let the radiator pivot forward almost an inch.

    I dont have a 3rd gen, so the following in how I do it on my 2nd gens. I take off the turn signal and passenger side headlamp (which also requires undoing the grill piece). This gives me the opening for the headlamp for squeezing the alt through. Must take off the serpentine belt - which I usually replace.

    Every alternator has a pair of ears on the backside of its case, where the long bolt goes through. On one side of that ear of the frame is a threaded insert. Its a press fit into the alternator case, and when installing a new alternator, the action of tightening up the long bolt pulls the threaded insert a couple of thousandths; so as to tightly grip the engine accessory bracket. Thats the reason the alt is stiff to remove, even with the long bolt and the short bolts removed.
    But I use a long screwdriver (or any long steel tool), and once the long pivot bolt is loosened a couple of turns, I hit the ear on the frame of the starter, right next to the threaded insert - a good smack of a hammer on the long steel tool. This moves the threaded insert a couple of thousandths of an inch 'away' from gripping the engine accessory bracket tightly. Then you can just flop the alternator out, after some turning and maneuvering. And since I have the opening where the headlamp was, I can squeeze it through there.

    My experience is that the starters wear out generally; not just a single part at a time. If the voltage regulator was okay, the brushes might be worn, the slip rings might be eroded, the small bearing at the back side and the larger bearing at the front side of the alternator might be worn (or the grease has dried out), or the diode pack or the windings might have some insulation flaked away. So I just get a rebuilt alternator, instead of hoping that a new volt regulator or new brushes will give the alternator another 10 or 20 years of service.

    I have replaced voltage regulators, and brushes, and bearings - and the windings and the diode pack were still old. I didnt have any confidence in it.

    I either get a rebuilt alternator from rockauto(dot)com, where I seem them from $117 on up (+shippng). OR... If I would find one locally for less than that, it would save me the fuss of needing to pay UPS to send the old one back. (Currently I usually just absorb the core charge as a business expense. I therefore have 3 or 4 old alternators lying around that "sort-of" work.) I have bought a rebuilt alternator from ebay, for much less than rockauto was charging, but I didnt use it on an Escort that I planned to drive across the country or into Mexico with.

    Sometimes the rebuilt alternator comes with a different diameter pulley on it than the old one from the car. In such cases I either remove the old pulley and swap it onto the new alternator, or a get a serpentine belt half an inch longer or shorter - as needed. I find its easy to swap the pulleys, using my electric impact wrench to undo and replace the hex nut on the alternator. There are two common sizes of pulleys, and I dont have any confidence the suppliers know or care which ones fit which cars.

    I can imagine taking my 25 year old Escort to a professsional repair shop, and getting an estimate of $500 to fix the alternator. After all, the mechanic may not be as old as the car, and have zero experience with such a vintage vehicle.
    I prefer no one touches my cars but me.

    On the side of the alternator where the volt reg is, there is a screw for one of the brushes - that if you ground it with the engine running, it will make the alternator produce full output. A set of bad or stuck brushes could still be the problem, versus the volt reg. Also the wiring to the connectors on the alternator could be loose or bad. There are two connectors. One has three wires to it, the other has a single wire to it. These can get pretty loose and flaky over the years; from sunlight. You can buy replacement connectors for both of them, from rockauto - but they wont be cheap.
    Last edited: Jul 25, 2019
  5. gimpel

    gimpel FEOA Member

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    yeh, torx head screws is what they are... mebe soak em with penetrating fluid so they dont snap?
    thanks for that about loosening the radiator, and removing the headlamp assy for access.
    the diode pack is part of the alternator? can i replace that without removing alternator?
    and thanks for explaining the tight fit on the alternator. and that bit about the different sized pulley (grrr... ) I dont have a shop and am lacking certain tools...

    in my first post I said that after charging my battery measured 12.8V which I realize is 'overcharged'. I only drove a few miles today... wanted to charge battery overnight again, but charger displays a fault code. finally found hidden in the charger manual that maybe it is because the battery is fully or overcharged, so i hope car will get me to work in the morning...

    My voltmeter died, and harbor freight was already closed when I realized it, so cant get another meter til tmrw, but here are voltages I measured this morning on the battery terminals installed in the car...

    car off... 12.84V
    motor running... 13.83V
    motor running and headlights on... 12.5V and falling

    so, the reading of 13.83V seems to me to indicate the alternator is good.
    and since the reading is low, and falling, under load, voltage regulator is bad?

    I know there is plenty of good info here on this forum about this, there is almost too much, which makes it hard to find the info I need... (and my forum searching skills are a bit rusty... ) I actually prefer written tutorials and how-to's over videos, but any responses or links to resources will be much appreciated.

    AFN...
  6. gimpel

    gimpel FEOA Member

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    btw, I first noticed problem after I drove home from work Tue afternoon. a couple of hours later, the car wouldnt start, so I got a jumpstart. Drove less than a mile, parked for an hour, car started right up, but after driving only a couple of miles, the car stalled at idle at a red light, and I needed a jump. needed two more jumpstarts that evening...
    If the appropriate idiot light lit I did not see it... what did happen is that the instrument panel went crazy! while I was driving, motor still running, intermittently the tach and fuel and temp gauge needles would 'die', all the idiot lights would flash, etc...

    a few minutes ago I read a very poorly written article on wikihow on how to test a voltage regulator... but, this article says the regulator 'limits' the voltage from the alternator from going to high, is that right?

    the instrument panel going crazy prob isnt because of the battery only being 12.08V, is it?

    it was Vinnie Barbarino on 'Welcome Back, Kotter', that would say... ' I'm SO conFused!'

    but, now I am thinking that the alternator IS at fault... the alternator is supposed to produce enough current so that it can provide approx 14 Volts (limited by the voltage regulator)... is that right?

    denis, you sed this which confuses me...
    On the side of the alternator where the volt reg is, there is a screw for one of the brushes - that if you ground it with the engine running, it will make the alternator produce full output.
    'ground it with the engine running' ?? jumper wire from that screw to GND? is that a test or a fix?

    If I were to give the alternator a few smacks in the right places with a hammer, might that be a temporary fix?

    millball, can I inspect or determine condition of slip rings without removing the alternator from the car?

    i need help...

    AFN...

    regards...
  7. denisond3

    denisond3 Moderator Staff Member

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    If you can get a look at the side of the alternator, it will indicate where to ground the screw to make the alt go to full output.
    Any battery charge to 12.6 or a little higher or a little lower can be considered fully charged. They arent all exactly the same, nor are most VOMs super accurate.
    But with the engine running, I would expect to see 14 or so volts. The problem is that it will depend on where you do the measurement; and what condition the battery is in. They can show a high voltage when charging, that really means they are sulfated, and have higher internal resistance. I would be suspicious of any battery that doesnt maintain at least 10 volts across its posts, even when the starter is cranking the engine.

    Yes, the regulator should limit the output voltage of the alternator from getting too high. An alternator that is artifically driven to full output (such as by grounding the screw on the back side of the alternator) , can put out 60-90 volts, if a battery is not connected and the engine is revved up.

    The instrument panel on a 3rd gen going nuts might be due to a voltage well below 8 or 9 volts. I wouldnt worry about that.

    Jumping-to-ground the screw on the side of the case is just a test, not a fix . It bpasses the voltage regulator.

    If you dont see the red light being on at the bottom of the cluster when the engine is running, it could be the light is burnt out, or that the contact on the alternator is loose. The connector with only a single wire to it needs to make good contract, or the volt regulator wont work stteadily. The signal to turn on the red 'battery' light comes from one of the contacts on the connector with three contacts though. Its a little bit counter intuitive how it works.

    If smacking the alternator makes it work briefly, I think it means the brushes are worn down, or the slip ring is worn or dirty.
    A problem with taking the voltage regulator out to see the slip rings, is that you need to use the pin slid sideways into a hole in the brush - used to keep the brushes retracted while you put the assembly back into the alternator. Not difficult, but vital when putting the brushes/voltage regulator back into the alt.
  8. rbailin

    rbailin FEOA Member

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    The alternator idiot light will light up with the key in the On position before the engine starts. With the engine running, it will light up when the alternator output drops below battery voltage. When the battery voltage drops so much that it now matches the alternator output, the alternator light will again go off. Your engine will turn off shortly thereafter.

    Removing and replacing the alternator on your car should take less than 90 minutes if you work very slowly. The two hardest parts are removing and replacing the alternator from its bracket. If you ever played with chain link puzzles as a kid, where they come apart only when properly aligned with each other, that puzzle was meant to prepare you to remove this alternator.

    You don't need to raise the car or remove the wheel or splash shield. It does help to have a helper hold the 3/8" ratchet holding the tensioner while you remove the belt from the alternator. Make sure you know ahead of time which direction to move the tensioner to loosen it so that you don't break the square hole (the metal gets brittle with age). If the belt doesn't come off easily, or you plan to use a new belt, have a pry bar handy to help get the belt back onto the alt pulley.

    You have to remove the power steering pump hose clip and bracket first and set the hose out of the way a little towards the coolant bottle. Spray the 10mm bolts first with blaster because they may snap off otherwise.

    Disconnect the battery ground.

    Make sure you can reach the large top mounting bolt and the smaller lower mounting bolt using a large 3/8" ratchet (preferably with a flex head) for leverage. Make sure you can break each bolt free before continuing.

    Remove the bolt holding the alt wiring harness clip to the frame. Note how there's a tab that goes into a hole in the frame to line it up when re-attaching it. Unplug the large connector on the voltage regulator. Open the protective cap on the output B+ wire and remove the nut and the wire. Remove the stator wire (that drives the alt idiot light) and set the whole wiring harness out of the way.

    Remove the upper and lower mounting bolts. You may have to use a short extension or deep socket to help reach the lower bolt, and then switch to a regular socket without the extension.

    Now comes the fun part. IIRC, with the power steering hose as far to the left as possible (have your helper hold it), wrestle the top of the alt off the bracket and then pivot the bottom of the alt forward and up so it clears the A/C line and radiator. There's just enough room to do this so you can then remove the alternator, back side up, pulley down. Unfortunately, it only goes back in the same way, so pay attention when removing it.

    If you're reinstalling the same alternator, use a C-clamp and appropriate sized socket to press the bushing in the back upper ear so that it's easier to reinstall on the bracket.

    Remove the torx screws holding the voltage regulator and check the condition of the copper sleeves on the rotor. If the copper is worn down to the backing, you need a new alternator. If the brushes barely stick out of the housing, you need new brushes or a new regulator. If the pulley spins non-smoothly or there's a wobble side-to-side, you need a new alternator.

    If you have an alternator repair shop and it's reasonably priced, I'd use them to refurbish your own alternator. Aftermarket alternators are often a crapshoot. They use cheap regulators that output only 13.85V instead of 14.2V at idle, and light up the alt idiot light even when the alt is working (poor connection at the stator tab).

    Installation is the reverse of removal as they say. Use anti-seize on the bolt threads. Make sure the belt is fully on all the other pulleys and the tensioner is fully retracted (but no further) before you put the belt back on the alt. Use the pry bar to help (not a screwdriver).

    With the engine at idle, voltage should be 14.1 to 14.2 at the battery. With headlights on, blower on high and rear defogger on, it shouldn't drop below 13.8V. At higher rpms, it should stay above 14.2V.
    Last edited: Jul 26, 2019
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  9. Joey_Twowagons

    Joey_Twowagons FEOA Member

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    I give another vote to getting the original alternator repaired / rebuilt by a local auto electric place, if you have one.

    The original Ford parts tend to be better quality than aftermarket.
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  10. gimpel

    gimpel FEOA Member

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    thx all... will update...
    regards...

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