Advice on Speedo recording KM to Miles

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Stesaw
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Location: Coventry

Advice on Speedo recording KM to Miles

Post by Stesaw »

Bit of backstory, I've picked up a dash pod with a rev counter and clock, my current pod doesn't have the clock nor a rev counter. The one i've picked up is in a bit of a state with a great deal of broken plastic being held together with tape and glue, the ribbon connector is also in a bit of a state with the copper curling up on itself but I think is servicable. In comparison my current binnacle and cable is in very good condition, but obviously different and less complex. I cannot use the clock in it's current place if I were to swap the lot over as it's just blank. Having said that I do need to get a replacement top steering column housing and they have space for a clock so maybe I could put it there instead with a bit of wiring?

My Old Speedo doesn't have a trip or buzzer and is numbered 805 on the bottom and records in miles and seems very bouncy. The "new" speedo has trip and buzzer wiring but only reads in KMH and is numbered 500 with quite a bit of circuit board in it which I assume is for the buzzer and other magical stuffs. The needle is very smooth and doesn't bounce I guess it has some wizardy my old one doesn't.
I've carefully taken both pods apart and had a look at the speedo, I've noted they have different gears on the side which I assume is for recording Mileage / Kilometers on the odometer, the MPH gauge has more teeth and a different worm gear than the KM one. I assume the difference in teeth count is what records the miles / KMs (wrongly no doubt) however if that is the case then surely I could swap them over to allow the odometer to record in Miles.

I know tampering with mileage is illegal, but I don't see an issue if you set it to the mileage it was at on the old speedo/odometer.

Am I just making more work for myself in trying to do that? Is it even possible? Should I just use some flyleads to wire up the Tachometer / fuel / temp gauges to my old ribbon cable and leave my old Speedo in? I know you can hardwire a dash pod and get rid of the ribbon cable entirely but those kits are pretty darn pricey.
:run

Any thoughts from people with this kinda experience would be greatly appreciated :ok
1985 LeisureDrive 2.1DJ 5 Speed syncro conversion project.
1979 LT 2.0CH Westy project

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AngeloEvs
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Re: Advice on Speedo recording KM to Miles

Post by AngeloEvs »

The PCB is for the oil pressure warning system. Later vans had the ignition pulse and a second oil pressure switch which was set to operate at a higher pressure and were part of the oil pressure warning system which included a warning buzzer. You can still use the PCB to control the Warning LED but the buzzer will not function.

The kilometer speedo will need the MPH gear and worm to convert to MPH and the MPH fascia. It is best to remove the gear and the shaft together and strip the whole assy but remove any burrs on the end of all the shafts before attempting to tap the shaft through the gears and number barrels.

If your van is earlier than 86/87 then the wiring at the dash board connector will most likely be different and you will need to reposition the cables to suit the later membrane PCB.

Because of the lock down and lots of spare time, I can make you a fully assembled PCB if that helps, suitable for all vans including those that have a Rev Counter. PM me for details if interested.

ImageNewV3 wiring by Angelo Evans, on Flickr

ImagePCB Close by Angelo Evans, on Flickr
1987 DG Karisma LPG with remodelled interior

Stesaw
Registered user
Posts: 1892
Joined: 10 Aug 2019, 23:30
80-90 Mem No: 17004
Location: Coventry

Re: Advice on Speedo recording KM to Miles

Post by Stesaw »

Thanks for the info there Angelo, :ok

AngeloEvs wrote:The kilometer speedo will need the MPH gear and worm to convert to MPH and the MPH fascia. It is best to remove the gear and the shaft together and strip the whole assy but remove any burrs on the end of all the shafts before attempting to tap the shaft through the gears and number barrels.

I do have my old MPH speedo, however I am not sure I'd wanna take it apart as I could put in my spares shed and maybe sell if anyone needed one. Also that speedo only goes to 100MPH which is 160km/h whereas the KM/h one goes up to 180km/h. Would those gears be suitable or would I need to source ones that would suit?. I know there are gears with different number teeth so I'd wanna make sure I'd get the right ones and I wouldn't want to dismantle the other one if it wouldn't make the other work right. My van is an 85 so the cables are going to be in diff places.
My current issue I have is trying to take the needle off.. I've been very VERY careful as I dont wanna bend the shaft (ohh err) or snap the needle but the buggers wont budge..but that's part of the fun right?...
:run

As for the offer for the PCB I'll send you a message to discuss that :ok
1985 LeisureDrive 2.1DJ 5 Speed syncro conversion project.
1979 LT 2.0CH Westy project

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