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-   -   CLuster F%&K, 79 OB, where do I start? (https://rennlist.com/forums/928-forum/634493-cluster-f-and-k-79-ob-where-do-i-start.html)

sweet928 05-20-2011 11:10 AM

CLuster F%&K, 79 OB, where do I start?
 
My gauges have been starting to act up. First my oil pressure gauge got stuck 1/3 when running for a few months intermittently. Then it stopped working all together. Replaced the Oil Sender and no luck - still inop. Then speedo needle started doing some random popping up and down with seemingly no connection to anything else going on other then going slowly (never happens at speed). It also started bouncing when backing up every time. Then months later I started getting some intermittent master caution light which has now lead to having my volt gauge and tach poping off and even loosing all gauges except fuel level combined with the master caution lighting up. Comes and goes. Maybe every 20 minutes or so for a minute or two then gauges pop back to life. Short of the still inop oil pressure.

So my thoughts are my pod circuit sheet is failing, but it was replaced several years ago, a loose connector behind the pod or could it be the control modual for the master caution going? I've had the pin connection at the jump post checked and all "looks" good. Have a jump post cover and the car doesn't see rain.

The only thing that's happened with this new increased level of gauge problem is I did get stuck in the rain the other day and was on the way back from getting my new radio wired. It's a reputable shop that I know does good work. The installer said he only wired the new harness into the old splice from the previous head unit. No new connections and he didn't touch anything else. So where do I start?

Is there anything behind the radio that could be shorting out as that was coincidentally recently disturbed with the radio install. I guess I can pull the head unit and see if that does anything for starters. Any other suggestions?

cpayne 05-20-2011 11:23 AM

If it has a 14 pin connector like newer cars then the pins may need attention, or grounds need cleaning, board on the pod, wiring harness

tmpusfugit 05-20-2011 11:24 AM

There are 3 connectors that hook your gauges to your car. From your symptoms I would suspect the connector on the right hand side is loose or improperly seated, or missing the plastic tongue the flex board wraps around at the connector. I would inspect all 3 connectors for proper seating before going elsewhere. If all are seated and the conductors are not damaged where the plugs meet the board then removal of the cluster and careful inspection of the board, the connectors, and all the rest would be called for.

And "reputable radio installer" is similar in nature to "honest lobbist"...just FYI. I have seen their work too often from too many shops in too many cars...but I don't think that has anything to do with your problem in this case. Ask me about the holes in a 928 gas tank from a "reputable radio installer" and a $5000 installation....and no, not mine, I took it out and sold it for a few $$$$....

sweet928 05-20-2011 02:22 PM


Originally Posted by tmpusfugit (Post 8571042)
There are 3 connectors that hook your gauges to your car. From your symptoms I would suspect the connector on the right hand side is loose or improperly seated, or missing the plastic tongue the flex board wraps around at the connector. I would inspect all 3 connectors for proper seating before going elsewhere. If all are seated and the conductors are not damaged where the plugs meet the board then removal of the cluster and careful inspection of the board, the connectors, and all the rest would be called for.

And "reputable radio installer" is similar in nature to "honest lobbist"...just FYI. I have seen their work too often from too many shops in too many cars...but I don't think that has anything to do with your problem in this case. Ask me about the holes in a 928 gas tank from a "reputable radio installer" and a $5000 installation....and no, not mine, I took it out and sold it for a few $$$$....


Thanks for the advice. I'll start there.

I know what you mean. I am very paranoid with my baby -- so I did all the work and brought the car to the radio guy completely apart and just asked him to splice in the new harness to the old -- nothing more. (I like the wires to be soldered and shrink tube'd -- which I don't have the tools or the skills to do.) Checked his work before putting it all back together. No drywall screws anywhere near my car!

I liked the shop because they installed a blue tooth device in my last DD and I had to take it out before returning the car at lease end. They put that thing in there like it was going to the moon and back. Well done in every way. I find the best way to gauge someone's work is when you take it apart.

fbarnhill 05-20-2011 09:23 PM

Hi, not sure how many miles on your car but two things that you NEED to do are cleaning all the ground points and do an r&r of the fuse panel. There is a great writeup on SharkSkins website. Search for his user id, his site is linked to his signature. To cure the current problem I would remove the cluster, use an eraser to clean all the connectors before putting it back together. I have used this method on computer boards for years and it does work.

It would be nice for you to put your real name in your signature. It seems odd to call you sweet928.

Best of luck,

sweet928 05-20-2011 10:07 PM


Originally Posted by fbarnhill (Post 8572805)
Hi, not sure how many miles on your car but two things that you NEED to do are cleaning all the ground points and do an r&r of the fuse panel. There is a great writeup on SharkSkins website. Search for his user id, his site is linked to his signature. To cure the current problem I would remove the cluster, use an eraser to clean all the connectors before putting it back together. I have used this method on computer boards for years and it does work.

It would be nice for you to put your real name in your signature. It seems odd to call you sweet928.

Best of luck,

Thanks. I know of Shark Skin's site and will start with the POD. My car has 92k and I do know the pod has been gone though at least twice in the last decade by PO and so has the fuse panel, according to the records I've got. New wire harness's were installed and grounds were all clean last time I looked, but it's probably time to go though the car again.

David

tlsmith1999 05-21-2011 12:24 PM

On my 78 I had a problem where all the warning lights would come on and all the gauges would stop working, turn out to be the beginning of my ignition switch going out. Not the exact same signs you are seeing, but I would try turning the car off and back on and see if the gauges start working again.


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