 WARNING!-Bosch Rebuilt Alternators!!, A Must-read for all 914 DIY-ers |
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| 3d914 |
 Oct 22 2003, 10:27 PM
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#1
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Senior Member  Group: Members Posts: 1,275 Joined: 24-September 03 From: Benson, AZ Member No.: 1,191 Region Association: Southwest Region  |
I've been fighting the last week trying to resolve a alternator light that wouldn't go out - even after installing a rebuilt alternator, new regulator, and checking/cleaning all connections.
The source of the problem was only found after trying three Bosch AL75X Rebuilt Alternators. Based on BAP Auto, this is the Bosch replacement alternator for the 914/2.0. The problem is with the design of the black cover that fits on the rear of the alternator to cool it, and the recent rebuilt alternators. This cover does not come with the rebuilt, and must be removed from the core alternator and installed on the rebuilt - hence the problem. The three-wire connector that caries DF, D+, & D- to the relay board is in one bundle, and the B+ wire that goes to the starter solenoid is a single separate wire. The AL75X has two studs coming out of the back of the alternator. One stud is taller than the other to permit connection of the B+ red wire. (IMG:http://forums.pelicanparts.com/uploads2/Alt101066882267.jpg) Both studs on the AL75X have a large washer with an index tab, than a small washer, then the nut. The smaller stud (opposite the post for the B+ wire) is positioned such that the large washer will short against the cover when is is screwed down with the three small nuts. This is the source of the problem, and will not be apparent unless you check continuity between the red (B+) wire and the alternator case as you assemble the cover. The flat on the inside of the cover will hit the edge of the large washer. (IMG:http://forums.pelicanparts.com/uploads2/Alt131066882441.jpg) The solution is to 1) remove the large washer, or 2) snip part of the washer off - opposite the indexing tab. (IMG:http://forums.pelicanparts.com/uploads2/Alt171066882556.jpg) Then when the washer is installed and the cover in position, it will not short against the washer. (IMG:http://forums.pelicanparts.com/uploads2/Alt191066882613.jpg) It is suggested that once the cover is installed, that you check the red (B+) wire for continuity to the silver body of the alternator. There should be none. Hope this helps someone in the future. Enjoy! |
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| GWN7 |
Oct 22 2003, 10:49 PM
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#2
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King of Road Trips Group: Members Posts: 6,280 Joined: 31-December 02 From: Winnipeg, MB, Canada Member No.: 56 Region Association: Northstar Region |
Good article. Thanks for the heads up. (IMG:style_emoticons/default/smilie_pokal.gif)
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| Howard |
Oct 22 2003, 10:55 PM
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#3
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Incontin(g)ent Member Group: Benefactors Posts: 5,785 Joined: 24-July 03 From: Westlake Village, CA Member No.: 943 Region Association: None 
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Great! You will save someone a lot of grief.
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| McMark |
Oct 22 2003, 11:08 PM
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#4
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
I ran into a similar problem and I took the more neanderthal method of beating the cover so that there was no more contact. (IMG:style_emoticons/default/smash.gif)
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| Jeroen |
Oct 23 2003, 03:02 AM
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#5
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914 Guru Group: Members Posts: 7,887 Joined: 24-December 02 From: The Netherlands Member No.: 3 Region Association: Europe |
Great article! Remind me to move it to the "classic threads" once everyone is finished making comments
cheers, Jeroen |
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| cnavarro |
Oct 23 2003, 07:19 AM
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#6
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Cylinder Guru Group: Members Posts: 472 Joined: 30-December 02 From: Chicagoland! Member No.: 49 Region Association: None |
I found that out too the hard way when I was getting ready to power up my car for the first time in two years after a full restoration and new engine, etc. SPARK! i ended up taking off the cover and putting a plastic/rubber vacuum fitting cover on the stud and bolted it all back together. I wasn't in the mood to start modding the cover...
Charles Navarro LN Engineering http://www.LNengineering.com Aircooled Precision Performance |
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| rhodyguy |
Oct 23 2003, 07:29 AM
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#7
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,198 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
i will print this one and put it in the 914 3 ring binder. great job, well written, good pictures.
kevin |
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