The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 06-01-2018, 05:31 PM   #1
scottcleaver
Registered User
 
Join Date: Apr 2010
Location: cape coral florida
Posts: 11
1990 454SS tach

I have a 91 tach dash to put in my 1990 SS truck. I have done these before but lost the repin info. I have been all over web sites looking for that repin info but cannot find it. Anyone remember?
Thanks
Scott
scottcleaver is offline   Reply With Quote
Old 06-02-2018, 05:54 PM   #2
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,445
Re: 1990 454SS tach

To use a 1991 cluster in a 1990 truck, you have to move B15 to B11, A11 to A10, and A10 to A9.
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.
ChevyTech is offline   Reply With Quote
Old 06-02-2018, 06:03 PM   #3
scottcleaver
Registered User
 
Join Date: Apr 2010
Location: cape coral florida
Posts: 11
Re: 1990 454SS tach

Thank you very much. Which pin will serve the new lead from the tach?
Thanks Scott
scottcleaver is offline   Reply With Quote
Old 06-03-2018, 10:13 AM   #4
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,445
Re: 1990 454SS tach

You're welcome!
B11
Signal to the tachometer.
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.
ChevyTech is offline   Reply With Quote
Old 06-04-2018, 04:20 PM   #5
scottcleaver
Registered User
 
Join Date: Apr 2010
Location: cape coral florida
Posts: 11
Re: 1990 454SS tach

ChevyTech,
So your saying that the B15 connector that I'm going to move to B11 is a tach signal? I didn't think the 90 truck had an existing tach lead since it never had a tach?
Thanks
Scott
scottcleaver is offline   Reply With Quote
Old 06-04-2018, 05:59 PM   #6
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,445
Re: 1990 454SS tach

Quote:
Originally Posted by scottcleaver View Post
ChevyTech,
So your saying that the B15 connector that I'm going to move to B11 is a tach signal? I didn't think the 90 truck had an existing tach lead since it never had a tach?
Thanks
Scott
That is what I have in my notes but I just looked at a 1990 C/K schematic and it shows that B15 is a ground wire and it shows no wiring for a tachometer.

I have never done this swap and my notes were from other members input from the boards.

If I can find some free time in the next few days I will do some research and post my findings here.
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.
ChevyTech is offline   Reply With Quote
Old 06-04-2018, 08:42 PM   #7
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,445
Re: 1990 454SS tach

B15 On a 1990 is a shared ground wire.
B15 on a 1991 is the wire in from the ignition for a tachometer.

At this point I don't trust any of the information because it is from other board members.

The way I see it, on a 1990 you need to run a new wire in from the coil to the instrument panel.

On a 1991 instrument panel B11 is the shared ground circuit 450. The shared ground circuit 450 is in position B15 on the 1990 instrument panel.

So to me it looks like the new tach wire from the ignition should go to B15 of the 1991 instrument panel when put in a 1990.
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.

Last edited by ChevyTech; 06-04-2018 at 08:53 PM. Reason: Add more
ChevyTech is offline   Reply With Quote
Old 06-04-2018, 09:05 PM   #8
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,445
Re: 1990 454SS tach

Ok I looked at the schematics for the other wires and that information looks correct.

Move B15 to B11, Move A10 to A9, move A11 to A10

But then you have to run a wire in from the white tach lead at the ignition coil to terminal B15 of the instrument panel connector.

1991 looks to be the first year with wiring that includes a tach signal to the instrument panel.
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.

Last edited by ChevyTech; 06-04-2018 at 09:06 PM. Reason: Add more
ChevyTech is offline   Reply With Quote
Old 06-04-2018, 09:05 PM   #9
scottcleaver
Registered User
 
Join Date: Apr 2010
Location: cape coral florida
Posts: 11
Re: 1990 454SS tach

ChevyTech,
First of all thanks for hanging in there with me on this. Yes, on my 90 plug the B15 slot is a black ground wire. I have moved it to B11, that makes sense I believe. I will run a lead from the coil to B15 and hope the tach works. I will let you know tomorrow, I hope. Its awful hot in SW Florida now and working on the truck has become outside temperature sensitive. Thanks again. Scott
scottcleaver is offline   Reply With Quote
Old 06-04-2018, 09:13 PM   #10
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,445
Re: 1990 454SS tach

You are welcome!
I will check back on this thread but am fairly confident it will work.

I understand the heat slowing you down. The only reason I am available on the board is I am worn out from the heat and resting where it is cool at my computer, and it is most likely much hotter where you are.
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.
ChevyTech is offline   Reply With Quote
Old 06-05-2018, 12:28 AM   #11
Mr_Rich
Registered User
 
Mr_Rich's Avatar
 
Join Date: May 2006
Location: Santa Maria, Calif.
Posts: 508
Re: 1990 454SS tach

I remember that there was an empty terminal wire right at the top of the coil. Used to be able to hook up a dwell tach to read the rpms working under the hood during tune-uos.
__________________
1989 K1500 Chev. EC
Original owner; some of the aftermarket parts I've installed are Borla headers, Hypertech chip, Edelbrock water pump, and a Stillen rear disc brake conversion kit.
2009 Hummer H3T 3.7L 5M.
1997 K2500 Chev. EC 7.4L/ 4L80E
Mr_Rich is offline   Reply With Quote
Old 06-09-2018, 01:44 PM   #12
scottcleaver
Registered User
 
Join Date: Apr 2010
Location: cape coral florida
Posts: 11
Smile Re: 1990 454SS tach

Works great. B15 on the dash plug was the tach signal port. Extra wire coming off the coil to feed the tach was ea
sy. I hope this thread stays alive so that others can find it and easily do this task. Thanks for all the help.
Scott
scottcleaver is offline   Reply With Quote
Old 06-09-2018, 10:29 PM   #13
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,445
Re: 1990 454SS tach

You're welcome!
Glad it worked out well for you.
Thanks for the update.
The thread should be around for people to find with a search.
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.
ChevyTech is offline   Reply With Quote
Old 08-23-2018, 08:00 PM   #14
Luv68's
Registered User
 
Luv68's's Avatar
 
Join Date: Jan 2001
Location: Russellville, Tn and DeLand Fl.
Posts: 532
Re: 1990 454SS tach

Thanks all for this info, I am looking to replace the cluster on my 90 and was wondering what needed to be done.
Luv68's is offline   Reply With Quote
Old 08-24-2018, 11:31 AM   #15
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,445
Re: 1990 454SS tach

Quote:
Originally Posted by Luv68's View Post
Thanks all for this info, I am looking to replace the cluster on my 90 and was wondering what needed to be done.
You're welcome!
If you have any trouble doing your swap let us know.
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.
ChevyTech is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:10 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
Copyright 1997-2013 67-72chevytrucks.com