VH V8 Tacho wiring

[VH308]

Hi there,
was just wondering if anyone can help me with wiring for my tacho on my VH V8. The tacho I have works on my VL V8 but wont on my VH. Both have the same ingnition systems and coils. Any help would be great as it is becoming very frustrating. I am able to hold the - terminal on the coil and hold the tacho input wire and it will work if that helps to shead some light for anyone.

[chadd404]

is the tacho the std one in the cluster, if you can hook it up direct to the coil there is a problem in the loom, chase and find a fault like a break or broken
cheers

[EcotecVK]

because he said it works with the VL, i'd doubt it is a factory one (Wouldnt fit both dash's)

I'd say theres something wrong with your wiring, after market tach's pick up from -ve on a coil. Having said that people have told me before that on a VL onwards you cant just hook it up (VN onwards i can understand cause of coil packs but VL NFI why) or it won work/gets incorrect reading, which to me is a load of you know wht cause i fitted one to a mates VL once, that then worked in other cars he had (A VK Included)

[chadd404]

Hey ecotecVK you can didsmantle the cluster and remove the tacho for testing, so there is a possibility it is a std one, im not saying it is, but get your facts straight before commenting.
I have had them apart before and i know whats in side them!

[VH308]

Thank you for your input everyone. I sussed it out last night after lots of messing around and found for some reason the ignition module to be at fault. Swapped the ignition module from my VL and it worked fine. Dont know why because car ran fine with faulty module but tacho would not work. Anyway getting new module today and will also ring an auto elec to see if they know why as I am a qualified mechanic and it makes no sense to me, but its fixed so that is all that really matters.