Early 911 Electrical Issues- Part II
01-17-2002, 11:00 AM
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Early 911 Electrical Issues- Part II
Ladies and Gentlemen,
The mystery continues. . . the PO installed an MSD 6AL box and tach adapter. The factory CDI box remains in place (anybody know what BHKZ stands for, auf Deutsch?) but the wires were unplugged and laying in the engine compartment. Believing as I do that unnecessary wires are not only confusing but a fire hazard, I removed the blue with yellow stripe, red and black wires that have a three-prong plug for the bottom of the CDI on one end, and go to the 14-pin connector, an abadoned distributor lead and into the console. These were in one harness and it was a simple matter to remove the pins from the 14-pin connector (and note the variation in my log book for future generations).
Here's the QUESTION: the harness running from the CDI box also had a braided ground connection that led to a tab on the bottom on the box, between the cooling fins. This ground strap divided into 2, one was connected to the coil bracket and the other to the left timing chain cover. My guess is that the engine gets an adequate ground through the trans strap, and these were merely grounds for the CDI box for interference purposes, but does anybody know if they are essential to proper operation?
A bonus question: There are two additional wires that stick out of the firewall ahead of the oil pressure sender: these are a small brown and white, and a small yellow. Anybody know what their function is? I checked the wiring diagram but am unable to find anything that would make sense.
Thanks in advance,
John
'88 Carrera 3.2
'71 E (PCA H-Stock)
The mystery continues. . . the PO installed an MSD 6AL box and tach adapter. The factory CDI box remains in place (anybody know what BHKZ stands for, auf Deutsch?) but the wires were unplugged and laying in the engine compartment. Believing as I do that unnecessary wires are not only confusing but a fire hazard, I removed the blue with yellow stripe, red and black wires that have a three-prong plug for the bottom of the CDI on one end, and go to the 14-pin connector, an abadoned distributor lead and into the console. These were in one harness and it was a simple matter to remove the pins from the 14-pin connector (and note the variation in my log book for future generations).
Here's the QUESTION: the harness running from the CDI box also had a braided ground connection that led to a tab on the bottom on the box, between the cooling fins. This ground strap divided into 2, one was connected to the coil bracket and the other to the left timing chain cover. My guess is that the engine gets an adequate ground through the trans strap, and these were merely grounds for the CDI box for interference purposes, but does anybody know if they are essential to proper operation?
A bonus question: There are two additional wires that stick out of the firewall ahead of the oil pressure sender: these are a small brown and white, and a small yellow. Anybody know what their function is? I checked the wiring diagram but am unable to find anything that would make sense.
Thanks in advance,
John
'88 Carrera 3.2
'71 E (PCA H-Stock)
01-18-2002, 05:04 AM
#2
Race Car
I believe you are okay with removing the ground strap that was for your ignition coil and CDI box...the transmission ground strap should cover that issue.
As far as the brown/white and yellow wire, I know you have an early 911 ('71??) but I seem to remember on my SC that those were to the blower motor for heat?? Just a memory challenging "guess" on my part. If it's a PCA H-class racer, this part, if it ever existed, was surely removed.
...meaning, I dunno if your older 911s had blower motors for the heat??
As far as the brown/white and yellow wire, I know you have an early 911 ('71??) but I seem to remember on my SC that those were to the blower motor for heat?? Just a memory challenging "guess" on my part. If it's a PCA H-class racer, this part, if it ever existed, was surely removed.
...meaning, I dunno if your older 911s had blower motors for the heat??
