Altenator Wiring

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Jan 1, 2009 | 04:07 PM

#16

81-F-150-Explorer

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From: Northern California

Here is the Altenator section of the Ford 1975 Wiring Diagram. 1976 is Identical.

Jan 1, 2009 | 11:38 PM

#17

428f250

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Proper testing

The proper way to test an alternator for output is with a volt meter. The old pulling the batt cable off and seeing if the engine dies is a back-yard old school method that came from the generator days. Some alternators will remain self energized and some will not when you pull the cable. Best way is to leave everything hooked up and test voltage at the battery while running. Should be in the 13 to 14 volt range(make sure the batt is in good condition first). If it is not charging good at the battery, check directly at the back of the alternator, no charge there and you have an alternator/regulator problem. Sounds like your wiring needs some attention anyhow so when you get that fixed you can check it with a voltmeter and have a better idea of where your problem is.

Jan 1, 2009 | 11:58 PM

#18

428f250

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really?

Quote:

If you indeed had an S code engine it would then have to have regular 8 bolt heads installed otherwise it wouldn't work in the truck and after that it's no different than a grocery getter found on thousands of other trucks and cars.

Elongate a couple header bolt holes and it falls right in. Just calling it how I see it!

Jan 2, 2009 | 01:16 AM

#19

GeorgiaTriumph

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How different is the wiring for a 78 F150? I just got a 78 that had a 79 351W put in place of the six. Also the truck has gauges and not lights. The wiring is a mess but it works. I would like to clean it up or pull another harness and be done. Are there any differences due to the engine swap?

Thanks, Josh

Jan 2, 2009 | 09:06 AM

#20

Bullitt390

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Quote:

Originally Posted by 428f250

Elongate a couple header bolt holes and it falls right in. Just calling it how I see it!

Good luck elongating any header bolt holes when you have to DRILL new holes.

Jan 2, 2009 | 10:09 AM

#21

NumberDummy

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From: Simi Valley, CA

Quote:

Originally Posted by GeorgiaTriumph

How different is the wiring for a 78 F150? I just got a 78 that had a 79 351W put in place of the six. Also the truck has gauges and not lights. The wiring is a mess but it works. I would like to clean it up or pull another harness and be done. Are there any differences due to the engine swap?Thanks, Josh

I cannot tell you the difference, except the harnesses used in 1978 are different part numbers than what 1975/76's used (post #9).

1977 is different, as is 1979.

1978 F100/350:

D8TZ14305B .. Alternator Wiring Harness / 70 amp Alternator / Use with Gauges / Obsolete

No Ford dealer or obsolete parts vendor has any.
-----------------------------------------------
D8TZ14305D .. Alternator Wiring Harness / 40 or 60 amp Alternator / Use with Gauges / Obsolete

Don Sanderson Ford in Glendale AZ has TWO: 623-842-8762

That's it, no one else has any.

Jan 2, 2009 | 10:45 AM

#22

GeorgiaTriumph

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Thanks a lot Bill. I'm assuming its a 40 or 60 amp. I'll have to look into that and give them a call and see what they want for it.

Josh

Jan 2, 2009 | 05:15 PM

#23

81-F-150-Explorer

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From: Northern California

According to the wiring diagrams, there is no real circut difference, between 1974 and 1979, however, that does not mean that connectors, etc... havent been changed.