Hi All,

With SVA applied for I thought it was about time I checked the speedo....guess what it dont work...

Its a VDO Cockpit vision speedo (part of the set from Lowtension before they dissapeared). The sender is also from lowtension, model PSS199, it has 3 wires red, green and blue from the sensor to the speedo, and four magnets that are attached to the driveshaft flange with a metal strap.

I've worked out and entered the pulse required by dividing rolling radius of tyre into 1 mile then X 4 (4 magnets) this gave me a pulse of 3752

It seems to be wired up correctly, red wire to +, green wire to negative (both picked up from the back of the speedo. Blue wire from sender goes to terminal 8 on the back of the speedo.

With the car on stands, 1st gear, clutch out, nothing....then suddenly speedo jumps to 40mph..and stays there for a bit. At the same time, oil pressure, revs, volts drop and coolant, fuel increases. Not by much but definately enough to notice.

Any ideas what the hell is going on, I have tried messing with the position of the sensor and magnets, ran separate earth and live feeds to the sensor, nothing changes.

If I pull the blue (sensor) wire of the back of the speedo all the other guages work perfectly. (Tacho seems a bit on the slow side though)

This speedo sender states on the instructions it is 300 % better than the last one.....thank god I didnt get one of them.

Any help greatly appreciated.

Regards,

John

just a though but I might be wrong if it gives 4 pulses per revolutions should u have divided by 4

have you checked the following

http://www.etbinstruments.com/Wiring_Instructions.htm

also bought from lowtension but followed these instructions with no problem. I am running a 2 pin sender.

REgards

Agriv8

Thanks, for the suggestions, but still no further forward.

Kev99,
I was thinking that myself to start with, but went with the assumption that for each time the wheel revolved once there would be 4 'passes' of the magnets hence X4. Can anyone confirm if this is right or should I have divided by 4?

Agriv8,
Looked at this before but it does not relate to the sender I have, 3 wires on mine, the instruction with the sender say 1 wire to +ve, 1 wire to -ve and the left over signal wire I have connected to terminal 8 on the back of the speedo.

One thing that did occur to me was interference by picking up the pos and neg from the back of the speedo. To try to disprove this I connected pos and neg direct to battery and still got the same result.

Is it time to go get another sender or can anyone offer any reason why this is happening.

Expecting a letter informing me of date of SVA anytime now, so I am going to have to find a solution pretty quick, stlll got a few other loose ends to sort out before 'D-day'

John

John,

I bought a light duty one from ETB and had no joy with it. bought a VDO one from Ebay worked first time.

Vdo Pt. No. 804/7/14

there is a pick in my archive

regards

Agriv8

[Edited on 8/5/06 by Agriv8]

[Edited on 8/5/06 by Agriv8]

[Edited on 8/5/06 by Agriv8]