Turbo gauge & boost sensor wiring

allblack930 · 05-18-2003, 10:41 PM

Hi All,

Would someone know what color is the wire inside the dash that connects to the boost gauge on the Tach/boost instrument on a 79' 930?

Also, for the wire that comes from the boost sensor, is that connected to the boost gauge only or is it also connected to other points along the way?

Is it possible to purchase the wiring diagrams/schemas for a 930 from somewhere?

Thanks kindly!

TurboBert · 05-19-2003, 12:22 AM

The color of the wire inside the dash that connects to the boost gauge is Red and White. It connects only to the boost gauge but it goes through a cable connector (T14 on 'regulator panel' according to circuit diagram).

The wiring diagrams are included in the 911 Turbo Factory workshop manual.

allblack930 · 05-19-2003, 11:30 AM

Thanks TurboBert,

Pardon my ignorance but could you point me to where the 'regulator panel' might be located.

Also, where else might I be able to purchase a Turbo Factory workshop manual besides the certified Porsche dealers?

Thanks!

TurboBert · 05-19-2003, 11:15 PM

Wayne sells them; the part number is WKD-481-321.
Here's a link:
http://www.pelicanparts.com/catalog/shopcart/911M/por_911M_documt_main.htm

T14 is a 14 pin connector located in the left rear portion of the engine compartment near the fuse panel.

allblack930 · 05-20-2003, 09:29 AM

THanks alot TurboBert.

I checked out Pelican and it looks like I have to purchase various volumes of the manual.

C2later · 05-22-2003, 10:30 PM

May i ask why are you looking for the color code from your boost sensor to your boost guage? Just wondering if you have the same problem i'm going through. My oem boost guage is pegged to full boost position at all times.

allblack930 · 05-22-2003, 11:32 PM

C2later,

I bought my car not long ago and found that the boost gauge was not working (pegged at full boost at all time). I then decided to pull out the tach to check and sure enough the wire that was connected to the boost contact on the tach was not connected to anything else on the other end. The wire was also not the original wire so I was posting this question with the hope to locate the correct wire for the boost gauge. It's supposed to be Red & White but still I could not locate it anywhere in the dash.

I might have to run my own wire from the boost sensor at the back of the engine to the dash to get it working.

C2later, would you mind telling me what color wire is on your car that comes FROM your boost sensor in the engine compartment.

Thanks alot.

C2later · 05-23-2003, 10:39 AM

The color code wire from my boost guage sensor is.........MEDIUM BROWN W/WHITE TRACER...the same color that is in the factory repair manual. According to the wiring diagram,it's the same color wire that leads all the way to the booster guage.What color wire did you pull off the guage that was disconnected? Did you test your boost sensor to make sure it was ok?

allblack930 · 05-23-2003, 11:52 AM

Thanks C2later,

The one I pulled off was a red wire which is not original as far as I can tell and it also did not lead to anywhere from the boost gauge.

I'll take your advice and will look for MEDIUM BROWN W/WHITE TRACER wire. Did this info come from a 79' turbo manual or a later year model?

I did try connecting a sepearte wire directly from the boost sensor to the boost gauge and it worked but I'm trying to locate the factory wire if I can.

C2later · 05-24-2003, 01:50 AM

Check the color code on the wire that comes off your boost sensor.If it's like mine, it will be brown w/white tracer.(matches the wire diagram section in the 78/79 PORSCHE turbo factory repair manual). This wire will lead into a harness from the engine to 14 pin connector on the rear side of what they call a regulator panal.(fuse panal on the left side looking in the engine compartment) Should be connected to one of the first two pins next to the wireloom. From there,that color coded wire should go all the way to your boost guage. You may have to cut open the wireloom at the 14 pin connector to check the color code and what pin the boost sensor is connected to?(if your careful,you can remove the top of the connector itself to ck. the color code)

magic930 · 05-25-2003, 09:06 AM

One of the causes of incorrect readings on the boost gauge is lack of ground on the intercooler (boost gauge gives readings at idle, or is always pegged etc.). The intercooler is somewhat isolated by rubber gaskets, adding a ground wire from the intercooler to the chasis can prevent the boost gauge giving false readings. Furthermore the stock boost guage is somwhat inaccurate anyway and the best solution is to add a a mechanical gauge and tap into a vacuum line after the throttle plate.

allblack930 · 05-25-2003, 10:51 PM

Magic930,

Would you know what might be causing the boost gauge needle to vibrate/jump. It seems to be responding to boost but it just vibrates like crazy.

My tach is also acting funny at times. Most of the time it is fine but then every so often it swings up and down erratically.

Thanks.