Question on Boxster turn signal switch OBC upgrade snafus...

03-25-2011, 09:33 PM

Oh well. I ordered the book 101 things to do with your Boxster. Tried the OBC mod on my 1999 boxster. Now not only does the OBC not function it will not step through the settings the lights on the LED MPH, TEMP, and LED odometer do not WORK!! Wow. First project, first failure.

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: Boxster On Board Computer (OBC) Upgrade / Boxster Turn Signal Switch Replacement - 986 Boxster (1997-04) -

Wayne 962 · Wayne 962's Garage

I'm going to to copy this question to the forums, and we can diagnose the issue there. At first guess, I'm thinking that your connectors are not properly seated in the rear of the gauge cluster.

- Wayne

jb99Boxster · 03-26-2011, 09:15 AM

I have to add that I am doing the poor man's version. I have the switches, etc. I think the problem lies in the type of molex connectors I used. I do not think the pins from the gauge cluster are seating tightly in the molex connectors I used. Does Pelican sell these connectors? Perhaps Digikey? In any case, the really confusing part is now the LED lighting behind the gauge cluster is off. The other back lighting works fine, turn indicator, etc. The switches have been checked and rechecked to match the correct pin out on the connector. Any suggestions would be appreciated.

jb99Boxster · 03-26-2011, 12:00 PM

Update. The molex connectors are too long. I removed the original 4 I used and then used 4 new ones. I trimmed them back by a 1/8" or so. This allowed the complete molex connector to be seated completely into the gauge cluster. No shorts. This is probably what was happening earlier. Now I can scroll through the settings of fuel remaining, temp, MPG, avg speed etc. I still have to figure how to work the gong etc. However, the LED back lighting is still off. Does anyone know where a pin out of the white (1999) gauge cluster can be found? I can't be sure this is even the connector for the LED light. Lesson learned. Trim the leads TIGHT and the molex connectors to below the level of the connector. More as I figure this out.

jb99Boxster · 03-26-2011, 12:43 PM

Update. Success!! Apparently thumping the bottom of the instrument cluster prior to reinstall jars something that turns on the back lights. Ok. So now that I have the OBC working I now have a loose connection in the instrument cluster. How do you fix that?? Anyway, all I can report is to double check the molex connector length. They apparently shorted when reinserted into the connector. Cutting them back to length worked. I'm sure there are a lot of seasoned mechanics who say "Duh, that's the first thing you do!" But hey, cut me some slack. It's my first boxster project. If anyone can give me insight on the loose light I would appreciate it.

Wayne 962 · Wayne 962's Garage

I'm not sure what you mean by a Molex connector? I recommend that you simply use the VW pins that we sell on the site to add a few pins to the existing connectors? I'm not sure exactly what you did during this conversion with the connectors, can you please elaborate?

-Wayne

jb99Boxster · 03-29-2011, 08:52 AM

The molex connectors are the connectors that insert into the instrument cluster connector connecting the male wire leads from the instrument cluster to the connector. The molex connectors are female. There is an accurate picture of the molex connectors I used at Digi-Key - WM2562TR-ND (Manufacturer - 16-02-0069)
From the photo you can see the two longer tabs at the end. These are used to wrap the wire and secure it to the molex connector. The wire is stripped to allow the tabs to grip insulated wire and not bare wire. I allowed enough bare wire to extend into the shaft to ensure connection to the male connector from the instrument cluster. To make it all work, I trimmed the longest tabs off then cut the connecting wire to length to allow the shorter tabs remaining to grip the insulated portion of the wire. I drop of solder to hold it tight at the top of the molex barrel. This molex connector isn't an exact fit. I then used a pair of needle nose to gently squeeze the barrel to a narrower diameter to securely fit the mail end of the shaft of the instrument cluster. I then inserted the molex connector into the instrument connector per the book.
Reconnecting the battery, setting the radio, and it works. However, now I have discovered the back light for the LED is loose. I suppose I have to take apart the instrument cluster and see if I can find the loose back light and tighten it up. Have you done this?

Wayne 962 · Wayne 962's Garage

While that sounds like a good way to save a few bucks, I would just use the VW part number I supplied in the article. That is the best way to get the best connection, as the different connectors use differently sized pins.

I'm not sure if the LED backlight is a separate bulb or part of the LED. I know it is part of the LED on other cars.

Keep us posted on your progress!

-Wayne

jb99Boxster · 03-29-2011, 11:30 AM

Honestly, I wasn't trying to save the money. I had some molex connectors from past electronics project I have worked on. I actually built a remote control lawn mower using powered wheelchair parts but thats another story. The molex connectors I had on hand were correctly dimensioned for the male pin in the cluster. They were just too long. Cutting them did the trick. I suppose the purpose of my updates was to warn newbee's like me that you have to watch out for the shorts. Looking back only the wires in pins 20 and 21 actually were touching. I have some documentation on the instrument cluster I was able to download that discusses disassembly of the instrument cluster but is a little fuzzy on how the guts work. I'm going to try to fix the lighting this weekend. I have to do this on the weekends as I drive the car everyday. 112,000 miles and still going strong.