scheefdog

I searched all over and can't find anything so sorry for this dumb question.

I pulled the instrument cluster out of my truck because I'm swapping in an SR5 one with a tach. There are two wires that connect above the speedo cable that were disconnected when I pulled it out of the dash. Which one goes on which post? There is a white/black and a green/blue. See the pic below of the new cluster with wiring harness.

There seems to be a lot of info on swapping a cluster for 82-83, but not a lot on 79-81. Everything I've read is that it is plug and play. Anyone done this and discovered differently?

Thanks!

scheefdog

So I ended up pulling apart the new instrument panel because I couldn't get the tach working even by running a direct wire from the ignitor. I checked all the wires and they are in the same places on the plugs.

Upon inspecting the tach I noticed there was a melted resistor. I know this is a shot in the dark, but worth a try. Will someone please look at their 79-81 cluster(with a tach) and tell me what the color coding is on the resistor? You should be able to see it by just taking the plexi and gauge surround off.

You can see in the picture where I took the resistor off. I'm hoping I can just solder in a new one.

Thanks!

biosys

Toyota use a White/Black wire for every ground in the vehicle so this is ground.
The Green/Blue is possible the TCCS wire.
Not much info out there on 70's and early 80's Toyota's.
I hoped this helped.

scheefdog

Anyone on the tach?

Somebody must have one of these sitting around waiting to be installed. I'd really like to try to get this thing working instead of having to find another cluster.

dropzone

iTrader: (6)

i am gonna forward your thread to my buddy Paul. He has parted out several trucks, he might have the instrument cluster stashed and can take a look...

trekkerpaul

iTrader: (3)

Thanks for the forward Robb. I have a bunch of extra tach clusters here and will go take a look at one of them for you. I was wonder about the resistors going bad a while ago when the tach stopped working on my Trekker. I replaced it, but never got around to checking out the original damaged one.

I am not sure which resistor you removed, but maybe once I have a good tach out of a cluster I will be able to tell which one yo removed. The resistors should be available at Radio shack?

trekkerpaul

iTrader: (3)

I just took apart a couple 79-81 clusters. There appears to be two different set ups, but one of the tachs matches your configuration. The colors left to right appear to be gold-black-purple-yellow. Please post the part number and where you got the part when when you complete your repair. Hope this helps

scheefdog

Thanks for the replies and thanks Paul for looking at the resistor!

So I went down to Radioshack and they had the resistors, pack of 5 for $.99. Definitely worth a try. The RadioShack part # is 271-1105. You can also see the type in the picture.

Soldering the new resistor in was easy. Now time for the test....

Tach still doesn't work. Damn. I tested it a couple different ways and nothing. I guess my search continues for a 79-81 cluster with a working tach.

Paul- Do you by chance want to sell one of your extra clusters?

suncomb1

If the resistor was fried, check the aluminum ribbon on the board for a crack or over heating damage. If you fine a bad spot, use an Ohm meter to check on continuity across the damaged area. If you find an "open" section, you might be able to solder it.

scottd

If you manage to get that tach working, I'd like to hear about how you did it. I have 3 instrument clusters with tachs. 2 do nothing and one works but intermittently reads 500 rpm high or so. Would eventually like to get one of them working right.

83

Sounds like someone could make a little cash on the side if they figured these things out...

Has anyone noticed that the later model (82 & 83) tach's seems to work better? It seems to always be the earlier model clusters with the tach in the middle that don't work. Those are my favorite style tach, too..

scheefdog

I couldn't find anything else that looked wrong with the tach, so I gave up and I'm on the search for another one.

I agree with 83, it would be cool if some electronic guru out there could figure out how to fix these things.

83

Ah, too bad.

Usually, with these things, it doesn't take anything near a genius...just somebody who keeps at it and stumbles onto the answers.