Replacing Voltage Regulator with Alternator in place

[nelsonj]

Hey all,
I just finished replacing my voltage regulator (55 amp Bosch) without removing the alternator. Not the easiest thing, took me two sessions but here are a few tips in case you want to try.
Tools I used
1) Stubby flat head screw driver
2) Needle nose vise grips
3) red plastic straw from a WD40 can
4) Volt meter

Removal:
IMPORTANT: Disconnect the positive side of the battery before starting. The battery connect directly to the alternator and its impossible not to touch the live wire in the process.
1) Two flathead screws. You can see the top screw, the bottom is completely blind.
2) I had very little room (cold side mount) and had to use a stubby screw drive. The (original) screws were very tight and, coupled with no room, I couldn't break them by hand. Trick 1- I used needle nose vise grips to grab the handle of the stubby, and then had a lot more torque. Presto - screws came right out. But the blind one with no room took some patience, and without the vise grip handle I couldn't have got it off.

Installation:
1) Man, it was very difficult to get the spring loaded brush device aligned with the screw holes. I had no visibility, very little room, and way too many degrees of freedom in movement, and very little grip on the little screws. It would by super easy with the alternator out of the car, but with the alternator in place, after about 2 hours I gave up...but
2) Trick 2: I used the red straw from the top of my WD40 can, put it in the BOTTOM hole of the voltage regulator (VR), and then put the the other end of the straw in the bottom mounting hole. I slid the VR on the flex straw and put it in place. Now I had the bottom hole in the right location, and I was able to rotate the top into position, and I had the top screw in within 10 mins. Success.
3) Tighten the top screw pretty tight and make sure the VR is completely flush with the alternator, and when the screw is pretty snug (but can pivot if convinced) then, and only then, remove the WD40 straw from the bottom hole. The bottom screw hole (that is entirely blind) should be pretty much aligned, and the bottom screw should fit right in.
4) Tighten everything the best you can by hand, then use the needle nose vise grip trick to make sure everything is very tight (this was a must for my bottom screw.)

Test:
RECONNECT the positive lead of the battery.
1) Make sure all you tools are out of the engine, reconnect anything you took off to make clearance and start the car.
2) Start the car and test the voltage at the output terminal of the alternator. I got 14V with the headlights off and about 13.9V with the headlights on.

Good luck - I couldn't have done it without the WD40 straw trick.

Peace.
Out.

[maxdog]

Why bother ?? Were you stuck in a parking lot at midnight with a spare regulator in your hand ?? Are you taking a course in Practical Masochism ??
Removing the alternator and working on the bench would be so much easier .
But as my granny used to say " It takes all sorts "
Maxdog

[nelsonj]

Why bother ??... Removing the alternator and working on the bench would be so much easier .
Maxdog

Some people call it "throwing good money after bad". I first looked at it and said "it's only two screws - it will be a piece of cake and a lot easier than pulling the alt, plus all the wiring...", but you never know until you try. It wasn't so easy to move my alt to the current location, so perhaps my alt setup isn't as accessible as some. I came up with the straw idea and thought I'd give it a try first - if it didn't work I would just pull the alt. The straw worked, the alt stayed put.

Sort of the point of my post - with my "tricks" I'm not sure what is the best approach but I think leaving the alt in place is a reasonable approach. Without my tricks, pulling the alt is the way to go.

[spider2081]

Why bother

I have changed a number of regulator/brush assemblies on Bosch alternators with out removing the alternator. I never uses the "trick" mentioned just held the regulators in place and screwed them in. I do understand why the Straw was used as its a tight area to get both hands in.
Thanks for the tip.