1970 Fleetwood Brougham 20k miles alternator bracket help

[Tonyv_73]

hello,

I just got my 1970 fleetwood back from having the engine bay restored, the car has 20k miles but didnt hold up well under the hood.  The alternator was not put back on correctly and was about 1/2 inch too far back, causing the belt to run crooked which cooked the alternator.  Im currently replacing the alternator and i think im missing the lower bracket.  theres a spacer and a long bolt but no bottom bracket for the alternator.  can someone send me a picture of what the bottom bracket would look like for this 472?  I've seen some on ebay for a 76 deville, not sure if its the same setup.  Also unsure if this car originally has a smog A.I.R. pump (if it did its missing) I dont believe it did but if someone can give more info on that it would be much appreciated.

thanks,
Anthony

[Cape Cod Fleetwood]

The alternator is attached only to the arm on top, there is nothing on the bottom.

[Tonyv_73]

The alternator is attached only to the arm on top, there is nothing on the bottom.

the bottom of the alternator is bolted to the block, but there is a bracket underneath that i am missing

[76eldo]

Laurie
That’s not correct.
There’s a rear bracket that mounts to the engine with two inserts that the alternator bolts to.
That’s in addition to the top bracket.

[Cadillac Fleetwood]

Laurie, I beg to differ.  The lower bracket and support, though present, are not visible in your photo. The alternator is supported with a bracket at the approximate 6:00 position.  There is also a bracket with a threaded, raised dimple mounted to the engine behind the alternator. The long bolt at 6:00 passes first through the bracket, then through the ear of the alternator, and then through an aluminum tube which serves as a spacer between the alternator and the dimpled, threaded mount. This is to position the alternator in the proper fore-aft position to line up with the belts/pulleys. This lower bracket has an elongated hole in it that allows the alternator to be lifted out of it (sideways and up) when the lower bolt is loosened sufficiently, and the bolt from the top bracket has been removed

Charles Fares

[76eldo]

Charles

Do you have a correct rear bracket for Anthony ?

[Bill Balkie 24172]

Hello  Laurie ,
      The picture you added showing the top of  your alternator  looks like it is bolted to the wrong side of the bracket  . I could be wrong .  I have included a picture I just took of the way mine is mounted .
    Bill

[Cadillac Fleetwood]

Bill, your upper alternator bracket positioning, vis-à-vis the alternator, is correct.

-Charles Fares

[Bill Balkie 24172]

Hello Anthony ,
        I have added a picture of the plate with the slot in it . The Alternator is mounted to this plate ( back of Altenator) . I have also added a picture with a small piece of masking tape on it . That bracket is mounted beneath the long top bracket . It is bolted to the block on one end and has a slot for the 6 inch long bolt on the other end . That Bracket is only about 5 or 6 inches long .  Anthony if I were you I would go back to that shop . Chances are they have that laying around somewhere . It was most likely there when you dropped the car off .   I hope this helps .
    Bill 

[Tonyv_73]

i need the rear bracket that goes to the block, I found one for a 76 that is for sale, but not sure if its exactly the same, (20k mile car, i'd like the correct part, even it the 76 will fit)

[TJ Hopland]

I don't think there is any significant difference in the alternator brackets or location the alternator ends up in for these engines.   I think for 73? or was it 72 when they went to the internal regulator the rear part of the bracket changed because the boss for the rear bolt moved.   It doesn't seem to be critical to have that rear bolt so unless you are going for a 100 point show car that should not matter. 

My guess is things got screwed up because of the smog pump.   76 most likely had a smog pump.   A 76 with smog would mean the crank pulley had 2 grooves and they were was basically no space between the grooves.   Inside belt went up to the AC and then over to the PS.   Outside went up to the water pump then over to the smog pump.    Water pump pulley had a 2nd forward groove on it which is what went to the alternator with its own belt.   

If you wanted to get rid of the smog pump but not change any pulleys the only option is to try and move the alternator back just a little more than the width of the belt.   It has and can be done but the much more common and popular way to get rid of the pump is to change the pulleys to either stock ones from a year that didn't have a smog pump or aftermarket.

A non smog setup will have a significant space (like 3/4") between the grooves on the crank pulley.   This makes the forward groove align with the alternator.  The water pump pulley for this setup only has the single forward groove.

Note if you are swapping pulleys you ideally want to get/keep the timing indicator with the set because those varied over the different years.    Also note that 68-74 used a dual AC/PS belt so the crank pulley would have 3 grooves.   74-79 used the forward of the 2 grooves and a wider belt.   If you don't care what it looks like you can mix and match the single vs dual belts.   They seem to work ok just look funny because they either ride really high or really low.   

[Cape Cod Fleetwood]

LOL! I really wish my car was intact so I could have answered this question correctly with a quick look.
Sorry guys, the girl will go sit in the corner now.

[Tonyv_73]

update: I installed a 472 alternator bracket, and everything fit perfectly, however the car is not charging at idle.  If I raise the RPM it'll get to around 13.5/14 volts, but at idle it goes down to 12.5 volts, and with the headlights on, radio, and heater, the voltage drops to 11.5 volts.  The "Gen" light bulb works, and has not come on during this issue.  I tried 3 different regulators with the same issue, Im guessing its the alternator? Its a brand new rebuilt AC Delco alternator so I was wondering if there are any other possibilities for the issue?

[signart]

I would check the device you are measuring voltage with first to eliminate a false reading.

[cadillacmike68]

I'm pretty sure the brackets are the same from 1968 up through 76 or even 78-79-80. I have a 12SI case alternator on my 1968 and it bolts right in, and the 12SI is a mid-late 70s update from the 10SI or the older external regulator model 10DN originally on the 68. (which I still have).

[The Tassie Devil(le)]

I agree with Art, and check your device.

I have a Digital Volt Meter, (Only reads Volts) and thought that I always had good battery voltage, then I got a pretty expensive Multi Meter, and thought I would see how that went.   Boy, the difference was remarkable.   My Volt Meter was reading a lot higher, like 1 Volt.

Bruce.

[Tonyv_73]

I'm pretty sure the brackets are the same from 1968 up through 76 or even 78-79-80. I have a 12SI case alternator on my 1968 and it bolts right in, and the 12SI is a mid-late 70s update from the 10SI or the older external regulator model 10DN originally on the 68. (which I still have).

this later alternator you speek of, does it take a later regulator as well? what years should i look into?

[Tonyv_73]

does anyone know what the factory amps are for a 1970 fleetwood with AC? Part numbers are much appreciated.  I know its a 10 DN alternator, but Im going to try and find an original 1970 Delcotron alternator if I can find one

[TJ Hopland]

If you want a 12si to fit a 472-500-425 look up an 84 Cimmaron.   Its got an internal regulator, 78 amp unit with the small connector at the top.  If you got a 72? or for sure 73 and newer its a direct plug in.  Looks different than the 10's because its got an enclosed fan behind the pulley instead of the open one.

Earlier had the external regulator so some wiring changes are needed but how to make that conversion is pretty well converd online.   Case is more or less the same size.  Bottom long pivot is in the same place as the 10's as is the top ear.  What is different is the rear bolt, that is in a different spot so can't be used.

Many of the 70's Cad alternators were 63 amp so slight upgrade but not so crazy you really have to worry about upgrading wiring and have slipping belts. 

[Tonyv_73]

im looking for the factory alternator, For some reason the car is not charging at idle and I suspect the alternator isnt giving enough amps, otherwise theres a draw somewhere