Alternator and or voltage regulator problem

[metalsteed]

Can anyone give me a good lead on a parts supplier either a location or on line. My California SPF has a 1969 351W stroked to 393, dynoed @ 450 hp, 475 lbs if torque. While cold it revs high but after warm up I can be sitting at a stop light and it dies. I checked the output of the alternator at a parts store and though low rpms is OK, mid to high has little or no output. I plan on replacing the alternator and regulator, but I would like motor-craft parts such as are in the vehicle currently. Any suggestions?

[vanoochka]

http://www.superiormustangparts.com/

[Blas]

See your messages.....

[metalsteed]

OK, after having the alternator checked while operating in the vehicle it was found to not be putting out the amps at mid and high rpms. I removed it from the vehicle and tested it... it PASSED! I reinstalled it and disconnect the negative side of the battery, puff... Dead. Tried it several times and as soon as the negative side was removed the engine died. Might it still be the alternator, the regulator, or both. I understand that it could be grounded improperly from other post. Any thoughts?

[Blas]

Check the engine ground strap located near the starter. There have been problems with that chassis lug and the paint on a few cars.

[metalsteed]

I looked at the L shaped bracket welded to the frame that the ground is bolted to, it looks fine! I'm ready to take it in to a mechanic and pay a few dollars if I can't find a suggestion. Anything else it might be?

[Blas]

Just replace the alternator......that should do the trick.....You said there was no output at highter revs...tested at the parts store......post a photo of the alternator bracket...there was an upgraded bracket back in 1999 to get it farther from the exhaust...I'll compare it to mine...

[metalsteed]

Hey Blas or any others out there that can throw me some input. I think I found the problem. The alternator was bad along with the battery! Problem still not fixed. On the alternator a sticker suggest to replace the voltage regulator. While removing the voltage regulator I realized the brown wire (GROUND) from the alternator was screwed to the base of the voltage regulator onto the FIBERGLASS inside fender well (not much of a ground). Should I run a ground wire to the frame where the ground from the starter is, or some other part of the frame?

[PANAVIA]

The ground wire can be checked to see if it grounding.

AKA checked for continutity to a ground path.

1. place a test lead from a multi-meter , (you probably should have a multi meter , if not, ---get one , something basic under 50$)

----set to test resistance to the proposed brown ground wire on one end, -- and touch the other end to a known good ground , on an SPF the aluminum firewall is a good test spot. or bare metal on the engine block.

your multi meter should read 0.00 resistance. (closed circuit) , if it does --the brown ground wire is infact...ground.

--if not ( if it reads infinite resistance (open).) then yes, add the wire to ground it to the frame.

if you need to ground -- remember you will need to have metal to metal contact (no paint)

Steve

--UPDATE 8-27...

I checked and the Ground wire on the VR as located on the fender-well. It is a direct wire from the brown alternator pigtail lead. This means in order to be (have a ) good ground at the VR both ends need to be hooked up.

--Steve

[metalsteed]

I replaced the voltage regulator and grounded the brown wire from the alternator to the frame where the starter is ground. The ammeter fluttered +50 to -50 rapidly. Now the starter relay clicks once and the starter won't turn over. An excelerent and match or the ol 223 are starting to sound good! I know someone can come up with a better solution. Help!!!!!!!!!!

[metalsteed]

A new starter relay or solenoid?

[PANAVIA]

Send me a PM with a Phone number -- I think we need to talk this through.

[Blas]

Send me an email with your contact info and phone number, I'll send you a new voltage regulator and starter solenoid..I have some spares.
SPFWiringDiagrams@Comcast.net
Blas

[Austin_Snake]

I recently had a similar problem bringing up the new car. Turned out the Ammeter was bad. All the current in the car runs through it. It had soot all over it like it burned. A new part too! Autometer said they have discontinued making the ammeter and to replace it with a volt meter. The Ammeter (according to Autometer) is a fire waiting to happen.
So anybody have a space Cobra Ammeter Gauge they would like to sell?
Good luck,
Richard

[PANAVIA]

well in the year 2008 it is not too hard to go past 50AMPs constant so that makes sense.