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Discussion Starter #1
I just sent out my meters pod to Palo Alto Speedometers to fix it all up. They sent it back, saying that it was all fixed. But when I put it back in the car the speedometer, odometer, and trip calculator all still don't work. I was thinking maybe there might be a problem with the wires that plug into the pod, and run to other areas in the car.
~Any ideas what's wrong with my meters?

Thanks
Joe
 

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What year car? Reason asking...some are cable driven to the head unit....some are electonically driven at the head unit.

All of the manual spiders have a speedo cable of some sort. A mechanical cable connects the tranny drive to either the head unit or a pulse generator that feeds the head unit an electrical signal.

On some Ljets and all motronics a rare but common failure is the pulse generator. The spica cars were all mechanical as far as I know in regards to the speedo.

Best Regards,
John M
 

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My 88 Grad did same thing until I replaced a bad fuse

check those fuses, sorry I can't remember which one it was and I don't think it was listed.... My tach would work fine but even trying a manual run of pulse generator with a drill wouldn't show anything on speedo or odometers. New fuse did it.
artart
 

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But Mad North-Northwest
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a rare but common failure is the pulse generator
Does that failure happen often but infrequently, John? :D

Quick thing to check is the connector to the pulse generator...sometimes the connectors get corroded. If you have an S4 it's a three-wire connector on the firewall near the brake MC, for post-'86 S3 it's over in the driver's side corner.
 

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Discussion Starter #6
No, the meters don't ever move. I'll try to check out that pulse generator. What did you mean by "rare, but common problem"?
 

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Well boys what I meant to imply.....:D

The failure is rare.....

But the most likely failure is the pulse generator....

And check the fuse for the pulse generator. Should have three wires. The grey is signal. Then I believe..think...if I remember correctly...that it gets 12V from white and ground is black.:D

Best Regards,
John M
 

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Discussion Starter #8
Checked the fuse, need another idea

I checked the fuse and it was fine. I took the pulse generator off the car, but don't know how to test it. Need some help.

Thanks,
joe
 

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I have an 91 Spider and I have the same problem. My Speedo Cable is fried. Don't know why, but it is totally frayed. May want to check the cable. Just a thought...
 

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But Mad North-Northwest
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You can plug in the generator, turn the key to on, and drive it with a power drill and square drive. If the speedo works with that then it's the cable.

If that doesn't work, I think you can check the output between the gray wire and ground with a multimeter while you drive the sender. Should be something like a 12V square wave. No signal = bad sender, good signal = bad speedo head.
 

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But Mad North-Northwest
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Good question, and Mongo dunno. Since it's an electrical sender (I'm guessing Hall effect with a magnet on a rotating arm) it probably doesn't care, so you won't trash it like you would with a mechanical speedo.

That being said, I'm not absolutely certain of this so it might be best to check.
 

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Discussion Starter #13
1989 spider veloce, speedometer

Do I need to drive the car and spin the drill at the same time.
 

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It may be rare but it happened to my car last year (or maybe the year before?) I replaced the speedo cable but that didn't help. I ended up getting the sender from APE, they were NLA when I was looking and I checked all the US suppliers.
The sender for S3 and S4 spiders are identical but the wire lengths are different. The S4 has longer wires.
I used the sender from an S3 and spliced on the connector from my original one.
 

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my 88 veloce tachometer never goes over 3000, and now suddenly, odo & speedo are totally dead! So now she truly is a "time machine"
 
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