My LUMP has an HEI Dizzy with a Tach connection. I'm trying to trace where the correct wire from tach is located. From the back of tach I've traced the white wire with red end to 12v switched source but I don't know where the Green wire and white wire with Black end goes and I don't know which wire is supposed to go where? At this point I still don't own a wiring diagram and not sure where to get one.


Help needed.

 

Here's clip of the wiring diagram from the S1 Workshop manual. Have you had your tach converted for an 8cyl?

 

Ya know, the more I see how others have trouble with their Conversions, especially if they bought one someone else did, the more appreciation I have for the quality of mine. Any trouble I've ever had with my car, NONE has been in any way connected with the original engine conversion. Paperwork I have says the conversion alone cost $3100+ in 1986.

The HEI coil came loose from the cap twice leaving me stranded, but the that was a GM problem (which I fixed and it will Not happen again) having nothing to do with the conversion work.

Here is what the wiring on my HEI cap looks like:

There is no green wire anywhere.
(';')

 

Baudrate,
thank you for the diagram that's a good start. No I haven't yet converted tach to 8 cylinder yet. I'm just tracing out circuits at this point. From what I've read I need to install a 330 ohm resistor on tach.


Elinor,


The green wire is from the tach as the diagram illustrates.

 

Oh, my mistake, I misunderstood.
(';')

 

You must have the tach converted to 8 cylinder... resistor only works for later tachs.

 

Roger,


Do you have a resource who can convert the tach or is it cheaper to buy a later style tach?

 

The PO for my car used Redline Gauge Works in CA. The invoice says "Convert to modern internals". $200.00

I don't know if that is required or not.

 

After your tach is properly converted to 8 cylinders... you can connect to the White and Green wires...

S1 hookup is totally different from S2/S3 and IT MUST BE CONVERTED to modern internal parts...

Have had Red Line Gauge Works in CA do this twice for my two S1 XJ Lumps... it will then look stock on the outside and work perfectly.
They will give you the instructions for the hookup...

 

Thanks for the info guy's that's what I needed. My speedo needs work too, it registers but is very jumpy (bad gear, cable?). I'll probably wait until I replace the transmission with an OD 200r4 to address it though.

 

You can convert the speedo to a GPS speedo that will be ACCURATE... plus you will gain other features...

By not adding the 90 degree speedo adapter and getting a new cable to your 200R trans... you can pay for the new speedo... plus trying to make a S1 speedo accurate is NOT FUN... they are also different from the later cars...

Good choice on the trans by the way! Have had two 700R with Lumps and love my 200R MUCH better.. I am have all the needed stuff for the TV cable hookup.. I just removed it all and the very special QJ Jet carb to convert to fuel injection. Getting ready to post all my Jaguar and GM conversion spare stuff in the Foir Sale section.

 

Roger, I respect your opinion's and advice having gone through this process of making a more reliable driver. Your advice has helped me greatly. I was eyeing the GPS unit but was reluctant to shed the original speedo, however I think your experience has convinced me to make the switch.

 

Is the S3 tachometer the same size as the S1? If so cant I do the resistor mode to convert to 8cyl? I can buy series 3 tachs for $20.

 

No, not the same size... S1 are DIFFERENT!
S1 is five inches in OD and S3 is four inches...