Hello everyone, I recently acquired a 1988 Jaguar XJ6 Vanden Plas, incredible car, 30k miles, all maintenance has been attended to, the only shortcoming is that the car sat for a period of time. But it runs, and rides, flawlessly. More to my point, the car has a troubling issue with the tach. Everything else in the gauge cluster functions perfectly, but the tach does nothing at all. I am unfamiliar with the XJ40 platform, having only dealt with the Series 2 and 3 XJ cars, so any help would be greatly appreciated.

 

Hey - Welcome aboard mate!

I have a later model with a different setup of gauges but AFAIK there is an issue with solder joints on the digital dash binnacles - hopefully someone will chime in soon and fill you in on the remedy - plus the archive will have posts on repair for sure.

all the best

Larry

 

Hi Mr. Hotrod,

Congratulations on your incredible low-mileage VDP! How about some photos when you get a chance?

Larry is spot on that reflowing solder joints in the instrument cluster (IC) has solved many problems on those early XJ40s. Our member Rob Evenson has done that job on his '88 so you might send him a private message since he's been very busy lately. You can also used the Advanced Search function under the Tools tab above to search for posts related to instrument cluster solder joints.

On your '88, the tachometer receives its signal from the ignition coil/ignition amplifier. The amplifier is mounted on a flat metal heat sink plate under the ignition coil, and the White wire with Black tracer line that connects between the amplifier and one coil terminal also provides the tach signal to the IC. You might check the cleanliness and integrity of the wiring and connector at the amplifier. Hardening and deterioration of the wire insulation and connector plastic has been known.

The White with a Black tracer line connects to a Red wire with Yellow tracer line that connects to the IC.

You can download the '88 Electrical Guide at the link below, courtesy of forum member Gus:

http://www.jagrepair.com/images/Elec...Electrical.pdf

Please keep us informed, and please post some photos if you get the chance!

Cheers,

Don