[7up]

I have a 1999 Ford Taurus with a bad alternator. At this point and time I can't afford to replace it, so my question is I have an AC Delco alternator with a two wire internal regulator, and with some small mounting adjustments could it be installed as a temp until the right one is bought, and if so how would it be wired?

[odinn7]

I don't think installing a Delco in a Ford that it's not intended for is a good idea. There are too many things that could go wrong here.

[TxGreaseMonkey]

Don't even try it! It will not be compatible with your PCM, which could get fried. Instead, simply install a new voltage regulator/brush holder assembly, which should take only a few minutes. This is usually all that is needed, unless the bearings are shot. You will need a Torx 20 bit to remove and install the new voltage regulator/brush holder assembly. If you have an external voltage regulator/brush holder assembly, such as on a Vulcan engine, it's even easier and cheaper (brushes, $6.99, AutoZone). Also, consider salvage.

[7up]

Don't even try it! It will not be compatible with your PCM, which could get fried. Instead, simply install a new voltage regulator/brush holder assembly, which should take only a few minutes. This is usually all that is needed, unless the bearings are shot. You will need a Torx 20 bit to remove and install the new voltage regulator/brush holder assembly. If you have an external voltage regulator/brush holder assembly, such as on a Vulcan engine, it's even easier and cheaper (brushes, $6.99, AutoZone). Also, consider salvage.

I took regulator off and the brushes still look good

[CaptainRich]

I took regulator off and the brushes still look good

You didn't tell us what is "bad" about your original alternator.
The brushes are only one component of the repair. I would install the complete kit.

[7up]

You didn't tell us what is "bad" about your original alternator.
The brushes are only one component of the repair. I would install the complete kit.

I took it to autozone and they tested it and said it was bad,but didn't tell me what was bad just that it failed.also before i took it out the problem was that it would not charge the battery.

[TxGreaseMonkey]

Usually, that means the voltage regulator is bad. If you can, clean the brush contact area on the commutator with abrasive cloth and check the diodes with a multi-meter. The diodes (likely 8) should only allow current to flow in one direction.

[7up]

Usually, that means the voltage regulator is bad. If you can, clean the brush contact area on the commutator with abrasive cloth and check the diodes with a multi-meter. The diodes (likely 8) should only allow current to flow in one direction.

How would I check the diodes with a multi-meter?

[talaniman]

I think you do better finding the money for a new one myself, and calling around to get a few prices at the pick and pull/salvage yards would be a whole lot better than rebuilding the one you have and have never done it before. Car repairs are well worth the taking on of temporary small debts and in the US, many warranty companies can front you the money or the shop you choose, and you repay it. You may need a few things done like a battery and I would try those options before I jumped into the unknown even though you are trying to save a few bucks. A lack of a hundred bucks doesn't justify the time, and frustration of being stuck trying to figure out how to jury rig a simple solution, that may well cost more and keep your vehicle from use for longer than it's worth.

Make a few calls and see. What state are you in?

[7up]

I think you do better finding the money for a new one myself, and calling around to get a few prices at the pick and pull/salvage yards would be a whole lot better than rebuilding the one you have and have never done it before. Car repairs are well worth the taking on of temporary small debts and in the US, many warranty companies can front you the money or the shop you choose, and you repay it. You may need a few things done like a battery and I would try those options before I jumped into the unknown even though you are trying to save a few bucks. A lack of a hundred bucks doesn't justify the time, and frustration of being stuck trying to figure out how to jury rig a simple solution, that may well cost more and keep your vehicle from use for longer than it's worth.

Make a few calls and see. What state are you in?

One last question if I connect a multi-meter the pos to battery post and the negative to a diode I should get a reading right and if no reading its bad.

[TxGreaseMonkey]

Set the DMM to diodes and test each diode just like a battery--usually, the diodes are fine. Current should flow in only one direction, which will be confirmed when you reverse the leads. When I rebuilt the alternator to my 2000 DOHC Taurus, I installed a Taditel voltage regulator/brush holder assembly. It will not test okay on the auto parts store's alternator tester, even though it is good. It requires the PCM to function properly. 90% of the time, I can install a new voltage regulator/brush holder assembly and bearings for around $25. It's simple and fun to do.

[talaniman]

Positive to positive, negative to negative, should yield a value without the engine running, and the value should increase when the engine is running.

I do Not disagree at all with TGM's solution it must be noted.

[7up]

Set the DMM to diodes and test each diode just like a battery--usually, the diodes are fine. Current should flow in only one direction, which will be confirmed when you reverse the leads. When I rebuilt the alternator to my 2000 DOHC Taurus, I installed a Tatitel voltage regulator/brush holder. It will not test okay on the auto parts store's alternator tester, even though it is good. It requires the PCM to function properly. 90% of the time, I can install a new voltage regulator/brush holder and bearings for around $25. It's simple and fun to do.

The rectifier holder has burn marks around all of the connection points of the diodes.

[TxGreaseMonkey]

Parts of the write-up, below, may help.

Rebuilding Ford 4G Alternators

In most situations, if you want to save money or you are in a hurry, perform Steps 1 through 3; then, install a new regulator/brush holder assembly and replace the back cover.


1. Remove 3 screws (8mm) from the back cover.

2. Remove 3 screws (Torx T20) from the internal voltage regulator/brush holder assembly (Motorcraft 50U-10C359-AB).

3. Clean slip rings with #240 abrasive cloth. Ensure there are no grooves or ridges that will interfere with the brushes seating fully. Rotate the rotor and, using a file, carefully remove any ridges; finish with #240 abrasive cloth. This is one of the most crucial aspects of rebuilding an alternator. Many problems are directly attributable to the condition of the brushes and slip rings.

4. Test for continuity (ohms) between the slip rings, using a multi-meter. However, there should not be continuity between the slip rings and the rotor or rotor shaft. If the rotor fails either test, replace the alternator.

5. Remove pulley nut (24mm) and pulley.

6. Separate stator from the aluminum housing, using a flat blade screwdriver.

7. Test the rectifier's diodes (8) with a multi-meter. Current should only flow in one direction (forward bias). With the multi-meter set for diode testing, place the black test lead on the main terminal post (10 mm nut) that goes to the battery. With the red test lead, test each of the eight solder joints on the rectifier going to the diodes. The readings should be around 0.472 volts. If you reverse the test leads (reverse bias), the readings should be 0.0 volts. Replacement rectifiers are available, if any diodes are bad. If the diodes are good, the windings on the stator and rotor are likely fine. Diodes will normally fail, before there will be any burn damage to the windings.

8. Remove 3 screws (T20) from the front bearing retainer and remove bearing (NTN 6303-LLVA). This standard “303” bearing measures 17mm I.D. x 47mm O.D. x14mm Wide. I substituted a Ringball RBL 6303-2RS bearing ($2.72), with a C3 radial clearance, to withstand the high heat.

Important Note: Alternator bearings normally use polyurea grease (dielectric), to prevent fire in case of seepage.

9. Clean aluminum housing and back cover with soap, water, and a scrub pad—dry with a soft cloth.

10. Install a new 6303 bearing in housing, replace retainer, and tighten three T20 screws.

11. Press rotor shaft from stator.

12. Remove bearing (NTN 6203-LLH) from the rotor shaft, using a small puller. This bearing measures 17mm I.D. x 40mm O.D. x 12mm Wide. Ensure the new bearing also has a C3 radial clearance. The two bands you see on the bearing are not racing stripes--they are high tech tolerance rings, used to keep the bearing from spinning in the bore. Never reuse a bearing removed by a puller, due to the possibility of damage.

13. Press a new NTN 6203-LLH bearing ($2.57) on the rotor shaft, using the temperature mounting techniques described in the link. Coat the outside of thebearing with a light coating of bearing grease.

14. Seat rotor shaft bearing in stator.

15. Assemble the aluminum housing and stator.

16. Install new voltage regulator/brush holder assembly (e.g., Taditel T815 orTranspo F796) and tighten the three T20 screws. Taditel is an OEM regulator manufacturer for GM, ACDelco, Remy, and Bosch, among others. Ford does not sell replacement voltage regulator/brush holders or any alternator components; therefore, you will have to go aftermarket.

After installing an aftermarket voltage regulator, the alternator test machines at most auto parts stores will tell you the alternator "Fails." Output voltage will appear low (10 to 12volts). Be prepared for this, even though the regulator is good and will work properly, providing 14 to 15 volts, once the alternator is installed in the car. Ask the provider of the regulator for special instructions on how to test it. Here's an example of what I'm talking about:

http://www.taditel.com/index.php?page_id=286

Click the link that comes up. D&V Alternator Testers, which are used by many rebuilders, will be programmed to test aftermarket regulators properly.

17. Replace back cover and tighten 3 screws (8mm).

18. Replace pulley, tightening pulley nut 80 lb.-ft.


Ford does not sell new 4G alternators. They only sell remanufactured alternators ($243.90), where they install a new voltage regulator/brush holder assembly. The old bearings and rectifier are not replaced. Therefore, rebuilding your alternator is clearly superior to, and less expensive than($20.28), most remanufactured alternators on the market today. This is an easy, fun job.

[odinn7]

I'm all for do it yourself repairs and all that but at some point, you have to know when enough is too much. I have rebuilt alternators and, as TGM says, it's not that difficult BUT....you need to have some knowledge first or you may make the situation worse for yourself. It may be better to just find one from a salvage yard and do it that way...or ebay even. If you really don't feel comfortable (and from your questions, that is what I'm getting), then you may be better off just taking a different direction with it.