Will a V8 cluster work in a v6?

[Ash81x]

Quick question will a vr v8 instrument cluster work alright in my v6 calais?? id say the tacho would be up the sh*t with the different rev signal from the v8??

ANy ideas?/

Thanks

[deathsminion]

There is one resistor difference in the tacho. Otherwise it's fine. I'll get the details now.

[deathsminion]

On the back of the tacho there should be labelled resistor points. R2, R3, R4 and R5 are the ones that need playing with.

R3 and R4 need to be removed. Put the resistor from R3 into R2. Move R4 to R5.

[deathsminion]

There may be a resistor left over, from R2, don't worry about it.

[hakhawk]

hey, deathsminion, if a v8 tacho is put into a v6, what will happen? it just wont work? or erratic behaviour? as i have a tacho in mine, which im not sure what engine vehicle its from, but when first put in, it would work sometimes, drop out at different speeds, when brakes were applied, now it doesnt work. im going out now to see what resistors are in it.

[deathsminion]

The base idle will be wrong, that's about the extent of it. Your problem sounds typical of a bad earth. Mine did the same thing. Even check the negative terminal on your battery, as that's what went on mine.

[The1]

v8 has a larger fuel tank to i think so you'l need to flick the switch to change the fuel tank size.

[hakhawk]

ok, no bad earth, no dodgy connections, its just no go. i put the cluster in with the cover off, and tried to flick the needle up to see if it was sticky, but normally when car is off, the needle will slowly come back down, when its on, its shoots down with a little force. something strange is up with the tacho unit itself, dunno what though. im going to try and get just another tacho bit and try in it.

[deathsminion]

Sounds like it's wired incorrectly, or the tacho is damaged.

The1: Nope, makes no difference, the sender governs that in the fuel tank. The thermostat will be slightly off, but not by much.

[hakhawk]

from the pinouts on the back, it all looks correct, heres the deal, i have a series 1 vn, came with lvl 1 cluster, i got a vr/vs lvl2 cluster (not sure what it came from really) i took the tacho and fuel/temp units out of the lvl2 cluster, drilled holes in the lvl circuit board, put the lvl2 tacho and fuel/temp units in the lvl cluster. the fuel/temp work fine, but the tacho worked to begin with, then did as described above, and now doesnt work. im pretty sure the tacho unit is rooted, as the pinouts on the curcuit board are correct with the tacho unit.

[deathsminion]

Could it be the loom itself? I have heard of people frying looms when upgrading from level 2 to level 3.

[hakhawk]

nope, loom is fine, i even checked the signal wire from the ignition module to the loom plug. it gets a nice 13.8 volts at idle, all good. as i said, everything else is fine, just not the tacho itself. unless the ignition module has screwed the signal.

[deathsminion]

It would be your tacho unit then.
Do you have a multimeter capable of checking the continuity across the board? Could just be a damaged resistor.

[hakhawk]

yep, i sure do, even though i had it all pulled apart today, i checked the resistors, they all read a resistance, but didnt check their exact values, diodes were ok. i will have a look tomorrow arvo. will also be asking a few local wreckers if they have any units i can have(buy). otherwise, anyone got one lying around?