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Parasitic battery drain, is .4 amp too much?

 
Old 03-16-2011, 02:28 PM
  #16  
Jim Chambers
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Thanks Dave and Dr. Bob.

Confused about what "full time power on the trigger lead" means. I think you are saying that instead of getting trigger power when head is turned on, the trigger wire is always hot. That would lead to amp being always on. Am I correct.

I now have stock amp but the wiring was once used for a high powered system. I installed the stock 6 channel amp. I just grabbed the red hot lead available. Don't remember the trigger lead. I will check later today (wife thinks there are other things in life besides 928's).

The car was sold to me with the CD 2 with no code and an earlier 4 channel amp rather than the 6 appropriate for a 10 speaker system.
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Old 03-16-2011, 09:49 PM
  #17  
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Did not have time to do too much checking today but here is what I found so far:

Factory Blaupunkt 6 channel amp: What appears to me to be the "trigger" positive wire (small gauge) is always hot regardless of head unit (CD 2) on or off. Does that mean that the amp is always powered and is my mystery battery draw? When I disconnect the "trigger wire" from the amp there is no sound. Connected there is. Clearly the amp does not power the speakers when the small gauge trigger wire is disconnected.

There is also a red larger gauge positive to the amp connected along side a similar large gauge brown ground. I assume that is the primary amp power.

I have yet to pull the head unit to examine that end. Will do so tomorrow.
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Old 03-16-2011, 10:11 PM
  #18  
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Jim, my shop manuals are not at arm's length so this is from memory (you'd best look at the diagrams yourself):

In stock configuration, the constant (30-bus) power to the Head Unit actually routes through the factory amp. The head unit has another wire that runs back to the amp that turns on a relay inside the amp.

How were the stock 6-channel amp and head unit re-installed? Were the factory harness plugs cut off when the non-stock stuff was installed the first time? Or is all the wiring intact? The point of the questions is to determine if you've got wiring problems due to improper removal and installation of the various set-ups, or if you have a problem with the stock wiring, amp, or head.
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Old 03-16-2011, 10:27 PM
  #19  
Jim Chambers
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The multi pin cable from head to amp is factory. The other wires have been modified by PO.

I will pull the head tomorrow. I better take a look at the factory wiring diagram but doubt if what I have now resembles it!
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Old 03-17-2011, 02:33 PM
  #20  
Jim Chambers
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Dave, or anyone else who can read the wiring diagram (Sheet 8 in WSM):

My reading seems to show power coming from "coil" (is that ignition coil?) to the + terminal 2 on the amp. Terminal 1 is ground. Terminal 3 is connected to the radio and likely is the "trigger" for the amp. There appears to be a switch in the radio (on/off ****?) which allows power from the amp to the radio.

Also, I do not have the alarm wire connected to the radio support frame. Doesn't seem to affect anything as far as I can tell.

If I am reading correctly my system is not connected properly. I think I have ignition power to the head unit and then to the amp. Gotta do some more checking to be sure.
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Old 03-17-2011, 02:52 PM
  #21  
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The coil ( M326) you refer to is a noise suppressor, and may or may not be installed. If it is, it is on a metal plate directly under the radio ( usually).
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Old 03-17-2011, 03:57 PM
  #22  
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There is different device labeled "suppressor" with no number attached. The line I am referring to says "coil (M326)". No idea what the M326 means.
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Old 03-17-2011, 04:30 PM
  #23  
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Jim,
326 refers to a specific radio option that required an additional suppressor - hence in the diagram, if you don't have the '326' radio, the coil is missing and a bridge is installed ( see diagram page 8, just below the coil) . The other suppressor is always installed.
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Old 03-17-2011, 04:47 PM
  #24  
Jim Chambers
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Thanks Neil. Does the primary power for the amp/radio come through suppressor M326 to the amp and then on to the radio when it is switched on. I now have the "hot" line going to the radio first. I am thinking it should instead be to the amp first, from the suppressor to terminal 2 on the amp diagram. Is my thinking correct?

My radio option code is 691. If I don't have the 326 suppressor, where does the primary hot lead to the amp originate?
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Old 03-17-2011, 04:51 PM
  #25  
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Jim, the primamy feed comes from the Central electric panel via fuse 21. Based on what you say you have - the hot feed is the RED in my picture, and it goes to the AMP first, then back to the radio head ( GREEN). Without the coil 326, there should be no direct connection from the RED feed to the radio head.
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Old 03-17-2011, 05:21 PM
  #26  
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I will go do some additional exploration and likely be back with more questions. Thank you Neil, very helpful.

Last edited by Jim Chambers; 03-17-2011 at 06:00 PM.
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Old 03-17-2011, 05:57 PM
  #27  
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Jim, BTW, the M326 option was the Becker CR21 radio
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Old 03-17-2011, 06:04 PM
  #28  
Jim Chambers
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So since I have CD 2 the red lead should come from fuse 21 to the + lead on the amp. and then to the radio head through the green? I assume there must be a "trigger lead" from the head to start the amp. when the radio is turned on. Where does it get its power?
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Old 03-17-2011, 06:14 PM
  #29  
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Jim, can you send me a link ( or a scan) of the wiring diagram for the radio / amp combo. I'll be able to help you much better.
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Old 03-17-2011, 06:43 PM
  #30  
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The diagram I have is the same as you attached to your earlier post. Taken from the WSM.
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