Caddy alternator install

[Kenny_Z]

I'm finally getting around to testing out the Cadillac alternator. My alt is giving me some issues so I thought I'd give this a test run. I built this bracket to come off the lower exhaust support. I also was able to use one of those two turnbuckles I bought from Ebay for 8 bucks. I haven't welded in over a year so my welds look terrible but they're strong.





I read somewhere I need to swap the pulley from the old alternator but measuring this pulley has it matching up perfectly and my belt appears to be straight. Obviously I'm going to double check that tomorrow but everything looks to have fallen in place. I still have to clean up my welds, straighten out my cuts, clearance a bolt, and paint the bracket. I'll also have to extend the green and brown wires to the proper terminals. I have to remember to remove the old alternator's tensioner when I reinstall everything.

The best part about this set up is that I'm using the original belt and there are no modifications to anything under the car except 2 wires. I needed a longer bolt for the upper support and this created bracket to support the alternator. I can put my original in the cubby with the bolts and tensioner just in case I have trouble.

So, before I go any further does anyone have any advice or something I may have missed? I obviously don't want to fry anything.

[Ron]

I read somewhere I need to swap the pulley from the old alternator but measuring this pulley has it matching up perfectly and my belt appears to be straight.

fyi- The D's drive pulley is way smaller than the GM drive pulleys....There are several GM pulleys that will work to compensate...I don't remember the part number but a good match is the one that is the same size as the cast (not stamped) double pulley they came on their 7127 alternators.

[Kenny_Z]

I can't break 11.6 volts from the alternator on either pulley and various RPMs. I get 12.3 volts from the system without the car running but as soon as I crank it the voltage drops. Tomorrow I may test the alternator in another car just to see if it is bad.

As much as I wanted to be a little different I'm thinking "screw this project" and buying an alt from a Delorean dealer. It might just be the post failure blues combined with hunger though.

[ramblinmike]

I can't break 11.6 volts from the alternator on either pulley and various RPMs. I get 12.3 volts from the system without the car running but as soon as I crank it the voltage drops. Tomorrow I may test the alternator in another car just to see if it is bad.

As much as I wanted to be a little different I'm thinking "screw this project" and buying an alt from a Delorean dealer. It might just be the post failure blues combined with hunger though.

Is your alternator light coming on with key on, engine off?

[Ron]

I'd run it down to the auto parts if I took it off...most can load test it for free.
How did you wire it?
Does it gave a self exciter regulator?

[Kenny_Z]

I'll check the light tomorrow. I know I get a battery light when the engine is running. It doesn't have a self exciter. I'm starting to wonder if I swapped the 1 and 2 terminal. I'd go check now but it's midnight and raining.

[Kenny_Z]

Swapping the wires worked. I've got 14.8 volts at idle on the GM pulley. It was on there last. I wish I had swapped the wires before I went straight to the pulley swap last night. Would have saved a lot of trouble.

[Kenny_Z]

Went for a drive even though it's raining here. Everything seems to work perfectly together. With the lights, fan on 4, and AC on I never dropped below 13.5 even at idle. Before I couldn't do that without dropping below 11 volts.





The brackets are painted and reinstalled. Red seems happy with the modification but only time will tell.

[ramblinmike]

Great!