I have a 98 Hilux . The speedo sometimes cuts out and displays ZERO.
I have discovered that if I switch off the ignition and then switch it on immediately, the the speedo is activated again (seems to need a reboot!)
Does anyone have any ideas as the how to solve this please.

Maybe you have a short cuircut or something! have you check the cable to the speedometer! or just maybe its time for a new car??

Your instrument cluster is faulty. If you remove it and take it to an automotive electronics shop, they have the ability to rebuild it for under $250. Good as new.

why dont u just buy a new cluster!! Because in the long run its going to come out better then a repaired cluster am i right or am i right!!! ?????

I would think it would more likely be a short to that particular insturment. You would think anything else would make the other instruments go crazy as well. Check the fuse for the speedometer and the wiring first, then go a little deeper.

Rebuilding a solid-state instrument cluster makes economic sense. It's $250 vs $500.

It is always cheaper to repair component pieces if you can remove and re-install yourself. Removing an instrument cluster with the awesome directions that Haynes provides is my recommendation.

I always found the Hilux electric speedo's a right royal pain in the backside, I converted one back to cable without much trouble, try a wrecker for a speedo head, cable and a drive. Get a instrument guy to set the odometer the same and then have a couple of hours worth of install and whammo!! A cable speedo that is reliable!!!

Definately probably a short...would be cheaper to repair yourself, only if you know what you are doing or have a buddy help.