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Old 07-18-2011, 09:21 PM   #1
Telecasterjoey
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78 blaser tach cluster into my 86?

So I just picked up a working tach cluster for my truck. My truck is out for paint again and I'm dieing to know if the tach cluster will just plug in and work?
I know I've gotta hook up the tach to the coil, 12v, and ground but other than that is that all there is to it? My truck came stock with no clock or tach just the normal simple cluster.

I searched and couldnt find a definite answer. Thanks!!! oh and here's a pic!
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Old 07-19-2011, 07:31 AM   #2
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Re: 78 blaser tach cluster into my 86?

lights or gauges?
they don't wire the same and the sending units are different
if your truck didn't come with one it will have to be hardwired in
start by checking the paths on the circut board they have to be the same or some wires may need to move

sweet find BTW
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Old 07-19-2011, 07:25 PM   #3
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Re: 78 blaser tach cluster into my 86?

Dang not what I wanted to hear lol but makes sense!
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Old 07-19-2011, 07:34 PM   #4
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Re: 78 blaser tach cluster into my 86?

Gauge hook ups are different and the speedo is different as well. Old school is mechanical and yours is electronic style. You "might" be able to get a way to change everything. What I would do is get a wiring diagram for the old and new styles and get a plug with enough wire leads for that bezel. This way you can change over but the senders may be different. Great find indeed but I would look at selling it on Ebay and maybe going with a different setup.
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Old 07-19-2011, 08:01 PM   #5
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Re: 78 blaser tach cluster into my 86?

My speedo is mechanical ( just one nipple where the cable from the tranny clips) could I just put the tach in my stock cluster and just wire in the 78 gas gauge?
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Old 07-19-2011, 08:49 PM   #6
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Re: 78 blaser tach cluster into my 86?

Your tach would have to be wired in correctly separate from the cluster printed circuit board along with the fuel gauge. This "should" work without using the cluster. You would just have to take out the wires or actually if you reinstalled the correct wired on the correct ccircuit then you could keep the wiring without hacking and then you would just have to wire in the tach. I would look for a diagram your model. You might have the wires already there for a tach but nothing to connect to due to using the same harness and plug into the cluster but the factory could have used the different level of trim circuitry board.
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Old 07-19-2011, 08:51 PM   #7
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Re: 78 blaser tach cluster into my 86?

Thats a 78+ cluster.
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Old 07-19-2011, 09:09 PM   #8
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Re: 78 blaser tach cluster into my 86?

Quote:
Originally Posted by 1BadSS View Post
Thats a 78+ cluster.
Good or bad thing for me?
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Old 07-19-2011, 09:20 PM   #9
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Re: 78 blaser tach cluster into my 86?

The back of the tach just says coil, ground and 12 volt, and I have the harness for it.
Looking at the printed circuit it looks like it should just plug and go. I'll update u guys when I get the truck back
Thanks!
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Old 07-19-2011, 09:43 PM   #10
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Re: 78 blaser tach cluster into my 86?

be carefull doubt the coil wire is actually there
it would look right to plug in but ,follow the wires
like the gas gauge wire and others need to move in the plug itself
if you don't wana fry that cluster
i'd just wire the tach to the 86 cluster if it all works


did you score it at a junk yard ?

maybe this will help sort it out
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Old 07-26-2011, 06:06 PM   #11
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Re: 78 blaser tach cluster into my 86?

Here's a pic of the cluster all cleaned up and needles painted. I get my truck back tomorrow cant wait to put the cluster in! Also I cleaned and painted my fender emblems.
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Old 07-26-2011, 09:00 PM   #12
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Re: 78 blaser tach cluster into my 86?

looks good
hope it's all workin for ya!
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Old 07-27-2011, 10:13 PM   #13
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Re: 78 blaser tach cluster into my 86?

So I'm in the process of hooking up the tach, where on the distributor do I plug the tach into? All the guages seem to work I just traced the wires and the are the same!

If anyone has a pic of how they hooked the stock tach into their stock distributor that would be great!
Thanks
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Old 07-27-2011, 10:24 PM   #14
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Re: 78 blaser tach cluster into my 86?

It hooks up right beside power lead to dist.
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Old 07-27-2011, 11:54 PM   #15
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Re: 78 blaser tach cluster into my 86?

Directly on the distributor, right beside the power wire. Right on the cap, you can't miss it.
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Old 07-28-2011, 12:04 AM   #16
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Re: 78 blaser tach cluster into my 86?

Thanks guys, I dont have the clip though, I guess I'm going to have to find one similar and clip it beside the power wire.
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Old 07-28-2011, 08:31 AM   #17
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Re: 78 blaser tach cluster into my 86?

a normal crimp on size will work
this is one i removed from mine.....wasn't workin right
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Old 07-31-2011, 08:30 AM   #18
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Re: 78 blaser tach cluster into my 86?

Thanks guys, I've got it wired up and it works great! The only weird thing is when I shut the truck off the tach goes haywire. If I then turn the ignition on again the tach zeros out. When the truck is on it works perfectly. Is this just something they do? Or is the tach on it's way out?

Thanks!
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Old 07-31-2011, 09:32 PM   #19
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Re: 78 blaser tach cluster into my 86?

how does it go haywire?
any ive seen sit off 500rpm to 1000rpm when off
but zero when key on
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Old 07-31-2011, 09:53 PM   #20
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Re: 78 blaser tach cluster into my 86?

It's probably because the distributor slowing down and the read on each lead... maybe a resistor would help on the line but hard to tell the valence. So for everything else did it bolt right up or had to make some adjustments? I hvae a 1980 K10 and got a cluster from a 1978, haven't installed it either.
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Old 07-31-2011, 11:43 PM   #21
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Re: 78 blaser tach cluster into my 86?

it works great and is really responsive. When i turn the engine off it does a 3/4 turn counter clockwise sometimes more sometimes less. The cluster just bolted in with no modification!
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Old 08-01-2011, 08:26 AM   #22
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Re: 78 blaser tach cluster into my 86?

good it works but yup that sounds weird
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