Speedometer Circuit?
 

Besides the connector at the Spare Tire area, what other areas need to be checked for a Speedometer that works sporadically?

usually the connection point at the rear of the pod where the wave connectors go onto the speedo pins are dirty use an eraser to clean these points

Hi Merlin,

I failed to add that I just changed my PCB (Printed Circuit Board) and made sure all contacts on the Cluster were clean.

My test drive short but all my other gauges are working fine now. I will be doing a longer test today as I will drive the car to our local stadium where the SCCA Autocross is held to pick up my Magnetic Racing Numbers. Couldn't get 928 but I got 929.

Oh boy, cleaned the grounds above my CE Panel. Cleaned the plugs on the bottom row of the Panel. Found some corrosion on the first 3 (left to right). Still no Speedo. Although when I turn my wipers on, it blows the fuse. I replaced the fuse and it works fine on it's first setting (one click up on wiper lever), but when I go up another click, the fuse blows again. Help me Por Favor :(

Alan, any suggestions?

you have a ground issue possibly the wrong wiper switch installed .

magnetic stickers wont work on a 928 for the hood and fenders and doors

Actually, all was working even with the same Wiper Switch. It all happened after cleaning the grounds and plugs in the CE Panel.

Found out too late as far the magnetic sticker. I see it does stick on the rear quarters. I may have to cut the decal down to size.

then you need to recheck your work as you have a wire shorted possibly a wire pinched under one of the pod securing bolts

Yeah, I thought of that too Merlin. I'm bummed as I really screwed my stuff up over the weekend. Heres the low down:

1) Speedo Inop
2) Fuse blowing when using 2nd lever setting on wipers
3) No power to Side Mirrors
4) No Power to HVAC

a) Ran out of time today, but I rechecked the plugs at the CE Panel, ALL Good.
b) Looked under Pod to see any pinched wires, saw none. All wires were free as I verified by tugging.
c) Ruined my Euro Signal/Cruise Stalk by opening it up - springs and clips went everywhere. I used my old original (different) Stalk to see if the switch was bad. Still blew fuse on 2nd lever on Wipers.

Gave up, ran out of daylight. My next thing is to remove the POD again and verify wiring. Any suggestions? Ughhhhh!

Also, 1 ground wire that was kinda holding the CE panel from pulling forward. I don't remember it being from the ground bunch when I removed the bolts to clean the grounds. Was this ok to ground it?

Have you checked the pickup/sensor in the back of the diff?...

remove the suspicious wire from a ground and check to see ifs in fact a ground. See if the fuse blows with this wire removed, also drop the CE panel forwards and see if there are any melted wires back there the gray wires can sometimes melt onto one another so look carefully
also on your car the female metal connectors along the bottom of the CE panel can be pushed out of the connector housings as the pins can go down the unlocking side of the metal connector , so a close inspection might be due, to put the connectors on try putting them on at a very slight sideways angle so the male pins dont go down the sides of the female parts.
If your blowing a fuse then you have crossed a wire somewhere, its best to remove the pod and inspect all of the connections do this with the battery disconnected, take the pod off as well as all of the switches

Looks like all the wiper connections are on the C plug of the CE panel. Check the black/green wire at C1 to see if that's grounding out somewhere between the panel and the wiper switch.

Also check the green/yellow (53b) and the black/blue (53i) wires going from the wiper switch to the wiper motor.

If all else fails, replace fuse with the biggest one you have and the smoke will tell you exactly where the fault lies! http://forums.pelicanparts.com/suppo...leys/silly.gif

Will do on the suspect ground. The end of the ground wire had an eye with the exact size as the others so it kinda meade sense, I just don't remember it being connected prior to pulling the CE Panel forward. It really does look like I am pulling the Pod again, I just hate doing that since this is how i broke my tabs in the first place.

Raymond, where are you getting all these numbers for the wires? Can you post a diagram? Also, maybe a pic of your CE Panel.

Drove car to work this morning and my Instrument Lights were very dim and were aternating dim to off. Grrrrr, all this was fine before i went messing with the CE Panel.

What color was the wire you added to the ground connection point just above the CE panel? They should all be brown.

PM'ed you panel info over on your site.

It was brown like the others with a circular connector like the others.

Verified ground was correct as i had an old pic of the CE Panel and looked during lunch that there is 2 connectors on that left ground post.

http://forums.pelicanparts.com/uploa...1268682098.jpg

Removed the Pod and carefully looked at all the harness and even unraveled them up to the main harness, nothing broken or pinched or burned.

Moved on to the CE Panel. Removed "All" the plugs and made sure they were marked for easy install. Removed all the fuses. Gave both plug spades at bottom of panel and all the fuse areas a good scrubbing with a wire brush. Also removed all the Relays one at a time and brushed the spades and used a compressor to blow out all the debris and wire brush pieces from all areas. Reinstalled and got my Cluster lights back and bright, hvac working again as well as the power mirrors.

Wipers still short out on 2nd speed with and without that suspect ground connected. I also did the Dwayne write up on the PCB rivets with no change on the Speedo issue. Also, which wires in the spare tire are goes to the speed sensor in the diff?

I pretty much gave up for the night and buttoned it up as it's good to go for me to drive in the dark again.

Ding ding ding!!!! You are the $$ winner! Removed the sensor with a 10mm socket and cleaned the sensor and Divet where the sensor lives with a wire brush and steel wool. Now "EVERY" Gauge on my Cluster works perfectly for the 1st time since I started this Project.

Never got an answer on which wires are which, so I backed up my car on some ramps and investigated. The wires are 2 thinnest ones of the bunch. Hope this helps someone. Case Closed

Hey MPDano, where did you get your Printed Circuit Board

see my post here
http://forums.pelicanparts.com/porsche-928-technical-forum/530864-why-would-someone-scratch-circuit-board.html

Mine is an early OB Circuit Board which I got from 928 intl. You may want to contact them to see if they got your model. I believe I paid $101 for mine.

I posted mega pics of the process here:

Porsche 928 Forums dot com - View topic - Pics of my First 928 and Current Project

Do you have an accurate Voltage reading in the Pod??

Jon

I haven't compared to the hot post or battery yet, but it reads a little over 12v on the volt gauge. I will do a more in depth check this weekend. Just glad that I can actually see how fast I am going.

I think the best thing is to get a 3rd party gauge and mount it.

Also, my odo reset button got jammed (click, click, click) this morning and reset the reading for mileage, but didn't reset it right. Numbers are not a zero, etc. Do I have to open the Pod again to try and unjam it? I tried to hit the reset button multiple times but it's not moving.

Did you replace the spedo gear when you where in there? You may have some debris (possibly from degraded spedo gear)...I really don't remember how it actuates..just guessing.
Jon

Yeah, the infamous disintegrating gear has been replaced almost a year ago. My problem is the reset button didn't put the odometer in a straight zeros line (if this makes sense) and now it wont move forward. If it's not one thing, it's another :confused:

you have to take to pod out to fix the odo reset linkage

I was hoping you would tell me to "take the car up to 95mph and it will break the gear free or something." I'll probably break something else removing the Pod again. Just my luck :(

Did you disconnect the odo reset button?

What became of the wiper fuse issue?

Gonna work on that today. My coworker miraculously put my Euro Signal Stalk back together. I'm gonna put the CC Computer back too and see what happens.

Ok guys! Total User Error (ID10T). I was wondering when I was putting the Cluster back together, the halves didn't snug up. The Reset mechanism needs to be in a certain position before the halves are put together. On the back of the cluster, you can see a small hole that the mechanism has a pin that goes through it. Put it back together and hit the Reset and walla! It all went to zero's as it should. Took it for a drive and now my Odometer advances perfectly. Absolutely everything in my Gauge Cluster is now working as it should. Yessssss

Also, figured out my Wiper Switch issue too. Looks like the guy who worked my Air Conditioning last year smashed some of my wires next to the Wiper Motor (Expansion Valve Replacement) . I opened up the insulation and lo and behold, there were some shorting wires. Fixed them up and resolved my Wiper Switch fuse blowing and my Cruise Control Switch malfunction. I got's the Cruise Control now! Thanks rjm65, that Capacitor fix worked on the Cruise Control Computer too.

Here is where the electrical short was:

http://forums.pelicanparts.com/uploa...1269156135.jpg

That would be THE infamous flux capacitor.