Okay, this is not for a g-body car but is still GM and I can't find a diagram anywhere. I have a 1974 Chevy K20 that I put a tach/gauge cluster into from a C60 BIG truck-the cluster is pristine and I couldn't pass it up. Anyway, has anybody installed a factory tach in a 73-86 Chevy truck before? Where do the leads go? I am used to seeing filters on Montes, etc. but this tach does not have one. I can post a pic of it if anybody wants to see it. Thanks in advance.
Tach install question...
- Thread starter gbodystuff
- Start date
white wire goes to a dash light.
red wire goes to a 12volt ignition switch.
black wire is the ground.
green wire goes to the TACH TERMINAL on the distributer or the - side on the coil.
red wire goes to a 12volt ignition switch.
black wire is the ground.
green wire goes to the TACH TERMINAL on the distributer or the - side on the coil.
The wire harness for the truck tach has only three wires...one tan, one black and one pink w/black stripe.
DOUG213XRJ was talking about an aftermarket tach :lol:
Have you done some searching on Google? I've checked a little but haven't seen much yet on schematics.
Have you done some searching on Google? I've checked a little but haven't seen much yet on schematics.
Here's a pic of a couple of clusters I sold last year..you can see the wiring harness up front. The black connector goes to the back of the housing at tach location....pink wire with white connector goes to power/igniton in the fuse block, white wire runs out the distributor and the black was grounded.
That is the exact style of tach setup I was looking for when I found the one I did. Yours look like they were in nice shape, too! Thanks for the info-I had three wires...a pink w/blk stripe (IGN. +12V), a black wire wiht a slide on ground clamp and a tan wire for the dist. tach terminal. But, on the back of the cluster next to the tach plug in it says run at 1/2 engine speed only so I assume this cluster came from a diesel truck....i am now wondering if I can simply wire a resistor inline to the dist. lead or use a tach filter from say, a Monte SS to do this. I can't find a diagram showing a filter but I also am unsure what resistance rating to put it at...I may just buy an assortment of resistors and see what happens. I started the truck and @ idle the tach was reading 1600 RPM's...lol. I am still going to try and find a different tach assembly even though after cleaning this one, I like the way it looks a lot! Areally clean assembly sells for roughly 100-125 on Ebay but they are all dirty to an extent so it's a toss-up...after all, these tach clusters are getting pretty damn old...mine works great save for the tach jumping too high.
It won't simply be a resistor in-line to correct the rpm reading. There is a capacitor/resistor combo somewhere on the circuit board to get the correct reading. Same way with the G-Body, F-Body, etc. tachs. I came across a tach at the junkyard recently that is something like 40% off, a really weird #. My current tach still isn't quite right either, it's about 9% high still (reads 2400rpm @ 2200rpm).
Idk, there is only a three wire plug in with no resistors, capacitors, etc. anywhere to be found on the circuit board...looks like I need to get a hold of a GM electrical manual for this truck.
Here's a little info I found, not sure it will be any help, but it's a little background on the tachs.
http://gmtrucks.org/showthread.php?t=489
http://gmtrucks.org/showthread.php?t=489
Doober said:
Doober, I just purchased a tach filter and I'm trying to figure how it's wired in the tach circuit. I'm putting a tach from a '91 Trans Am in my car. I've heard that the filters are sometimes mounted on the firewall of the vehicle, any truth to this? If you know of a wiring diagram I would appreciate it. CJay
Similar threads
