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Removing alternator

 
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ronafios  



Joined: 14 Jun 2011
Posts: 26
Location: Canberra, Australia

PostPosted: Fri Aug 05, 2011 10:48 am    Post subject: Removing alternator Reply with quote

After battling electrical gremlins on my 924 and removing the alternator lots of times and ways, I though I would share my final 'best and fastest' alternator removal method. Feel free to add suggestions/improvements!

Haynes suggests it's possible to replace the voltage regulator on the car. Yes it is, but it's a massive pain with poor access. I suggest removing the alternator to do any work at all on it, including replacing the voltage regulator. I busted the first regulator I tried to install because of the poor access. Once it's off the car, it's simple to drop the whole thing in to an auto electrician for them to bench test anyway.

REMOVAL


1. Disconnect the battery.

2. Remove air intake hose that runs between alternator heat shield and the front intake.

3. Remove the ground strap that is typically connected to the alternator bracket/engine block using a 13mm ring spanner.

4. Remove the alternator bottom bracket bolt. It typically has a locknut on the rear. Use a 13mm ring spanner on the rear nut and a 13mm socket on the front nut.

5. Remove the alternator top bracket bolt. It typically has a 13mm nut at the rear and a hex key is required for the front.

6. The alternator should now be detached from the bracket, and you can remove the belt and lay in in-place horizontally to remove the heat shield and connectors.

7. The heat shield his held on with 3 x 10mm bolts. One should be fixing the other end of the ground strap. Remove the three bolts.

8. There are two connectors on the back of the alternator. The larger connector uses a 13mm nut, and the smaller connector an 8mm nut. The alternator can now be removed from the car.

Additional notes:

a) It is always worth sanding/filing the ground strap and connect points while the alternator is off the car. The rubber/poly bushings on the mount mean it is not grounded by itself.

b) A quick squirt of WD40 on the 10mm heat shield bolts helps them go in easily. They are easy to misalign and strip. Don't forget to sand the ground strap terminals !!

c) The wiring from the alternator is exposed to extreme heat and breaks down. Inspect the cable carefully, and do some resistance testing while the unit is off the car. D+ (large) typically runs to the positive terminal on the starter (this link is often broken) and through the back of the engine to a white connector near the battery. The B+ runs to the ALT dash light. The cables have often been bodged, and it's not unusual to see cabling run from D+ directly to the battery, bypassing the starter. Although this will work, it is probably not fused - meaning your alternator or battery will act as a fuse if anything goes wrong. Your starter may crank faster if you restore the connection. It is a 13mm nut, accessible with a socket and short extension.

d) Many cars seem to be missing the rear heat shield. If you can find one, it's worth putting on because of the proximity of the alternator to the exhaust manifold.
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ronafios  



Joined: 14 Jun 2011
Posts: 26
Location: Canberra, Australia

PostPosted: Fri Aug 05, 2011 10:52 am    Post subject: Reply with quote

Here is an example of alternator wiring loom gone bad (my problem....)



Even if your wiring looks OK, it's worth checking it out properly. In my case, the wire from the starter to the alternator loom was just hanging in place, disconnected from heat/corrosion, and potentially arcing against the engine block/body at various times...[/img]
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ideola  



Joined: 01 Oct 2004
Posts: 15548
Location: Spring Lake MI

PostPosted: Fri Aug 05, 2011 1:12 pm    Post subject: Reply with quote

Nice job. You should add a writeup on rebuilding the wiring harness
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raymie64  



Joined: 18 Oct 2012
Posts: 2
Location: scotland,greenock

PostPosted: Fri Nov 16, 2012 9:56 pm    Post subject: Earth straps Reply with quote

I am having the same trouble with my car and it looks like it has been a long term problem as the car was laid up for 5 years before i got it. It turns out my car didnt show the proper 13.8 to 14.2 volts charge and the car would start as if the battery was flat, although the battery was new. I also noticed the earth straps were replaced so asssumed these to be good. After much alternator removal etc i noticed the earth strap on the alternator to be the small side and somene had added another makeshift one, the alternator is rubber mounted so os detached from the rest of the car. I recharged the battery but still the slow starting problem continued. I attached a jump lead to battery earth then straight to the engine and another straight to alternator body,,, result? Instant fast starting and volt meter showing 14volts! So never assume because you see a new earth strap that it is good. Anyone had this trouble with thier car? Mine is a 924 2.0L n/a 1985.
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