Hi Folks,

Here is the scenario: Driving around visiting family (over 100kms away from where I live) yesterday I noticed each start the engine cranked slower than the last start. So, I pulled out my multimetre to do a quick check o the charging system and it was reading 11.5VDC at idle (should be at least 13 to 14VDC at idle, I just checked at the battery terminal not the alternator's stud) So I left the truck running for the last couple of visits and got to where I was staying for the night before dark and hooked up the battery charger to the truck over night.
It was about noontime today when I started the truck up for the 100kms+ drive home and it started fine of course (being on charge all night and morning). Drove home with no issues and then for some reason I decided to pull the metre out again and do another quick check and this time it read 13.5VDC at idle on the battery terminals and 13.8VDC at the alternator. A little bit of a voltage drop between the alternator and the battery so I think I'm going to clean all the connections anyway just to make sure but it was charging!

So, with all that said I have two questions:

1) Other than a loose connection, what would cause an intermittant charging problem?

2) I'm trying to find a new one online and getting a bunch of hits for my make/mode/engine without much additional info as to specific application. I know I have A/C so that eliminates some and I want to go with as high a amp rating as I can. Anyone know what part number I need to go with?

Thanks in advance!

EDIT: As a side note, through this whole 'adventure', the OEM voltmetre in the instrument cluster didn't move even a bit from it's normal position! I already know they are glorified idiot lights but this was a bit surprising!

 

130 amp
Powermaster 47750 - Powermaster Street Alternators - Overview - SummitRacing.com
200 amp
Powermaster 47768 - Powermaster Street Alternators - Overview - SummitRacing.com

 

Those won't be direct bolt on replacements, they are 2G, with serpentine belt pulleys. Cruickie's truck has the external regulator, with v-belts. There's some options for replacement, but bolt on is going to leave you limited on the output to around 60-65 amp if I recall correctly.

 

if 2g wont fit, what body style will?

 

May want to check the voltage regulator, and the connections for corrosion also.

 

In either '92 or '93 was the swap to serpentine belts, everything on the 7.3's and 6.9's before that were all v-belt. The units you listed would work, with a pulley swap, and some wiring changes (similar update to a 3G alternator from the Taurus that there have been threads about.) Likely good units, but it sounded like the OP wants bolt on replacement.

If you're looking for more output though, then there is some work involved...I'll see if I can find a 3G upgrade thread.

Found the last thread about it that I recall, should answer some questions. https://www.ford-trucks.com/forums/9...-alt-swap.html

 

I have a 1987 F250 that came with a 2G 75 amp alternator. I bought a 130 amp 3G alternator from a junk yard for $30.00 that came off of a 93 Taurus. Did have to change the pulley. Works fine.

 

I'm seriously thinking of doing this mod on a truck this year, does anyone know if you have to change the belt to a different length?

 

Greywynd: You're right, I am looking for more of a bolt on replacement. After reading up on it I would like to do the 3G mod at some point but not right now...

I cleaned up all the connections and I still have a intermittent no charge situation. This time when it stopped charging I put the meter right on the alternator and it was only reading about battery voltage and it did not change with increase in RPM. So, I'm alternator shopping!

As a side note: after I cleaned up all the connections I decided to pull out my test light and check my glowplugs. All the plugs on the left (drivers) side worked but all the ones on the right side didn't provide a ground. I figured I'd just replace the right hand bank with the ZD1A'a I ordered a while back and never got to but when I pulled the first one out it was a CHAMPION! Change them all I said to myself! All but two came right out. the rear two on the left are being stubborn. They don't even want to start threading out! Right now the penetrating oil is doing it's thing so hopefully that'll do the trick...

 

lmc has alternators that are direct bolt on. 100 amp.....

 

You can get bolt on replacements that go up to about 160 amps.

But I also have to say, you need to upgrade the wire from the alternator to the starter relay when you install them.
The stock wire will work for a while, but it just won't take that many amps for very long.

 

i was reading on a alternator site, anything over 95 amp on a v belt will start to slip, anything over 180 amp on a serp belt will slip

 

greywynd you have a PM

 

I'm not really looking to get into upgrading wiring or midifying brackets or anyhting like that right now. I'd like to order that 100amp from lmc but will by stock wiring handle that? Also, Oreocreaming mentioned that he read anything over 95amps will cause a v-belt to slip...

All that said, I found a couple 70amp units at rockauto.com (BBB Precision P/N 70729 and AC Delco P/N 3341999) and I'm thinking I may be better off to stick with them. I don't have a lot of extra accesories on the truck and I don't plan on installing much (maybe a couple extra lights... LEDs so they won't draw much) so 70amp would probably be lots for me, eh?


Also, GLOWPLUGS... got all but 1 out without too much problems but the 8th one (rear cylinder, drivers side) is not going well. I let is soak in penetrating oil and used lots of penetrating oil while turning it out (a little out, spray, then back in and out again...) But, after a bit doing that the hex snapped loose. Suggestions?

 

The 3g swap is the best way to have more power and save some cash. I got the alternator and the yellow 4ga charge wire from a 94 taurus for 25.00. Swapped the pulleys and made sure to add a 1/16'' inch washer to the 3g alternator or else the 2 groove IDI pulley will rub. I spent about 2 hours doing it and will not go back the amp output at idle is great.