Whats the wire diagram for the coil on a 1989 gmc

There are dozens of connection points. Try the following as a start.

https://www.autozone.com/repairguides/GM-Blazer-Jimmy-Typhoon-Bravada-1983-1993-Repair-Guide/WIRING-DIAGRAMS/WIRING-DIAGRAMS/_/P-0900c1528003db5f

Try here: Chevy Astro Vans GMC Safari Van

you posted a GM car to a rice burning Toyota Tacoma.
id bet there are not too many GM/toyota owners here.

but alldata.com has your facts.
login and read.
or buy the FSM.
or google it, there are like 1million hits on it.

New parts can still be bad , check for cracks also check wires for white arc marks on each other or where they might contact a ground source .

Hi.

Below you get all the parts breakdown for GMC Sierra 1500, including steering column assembly:

1500 SIERRA

Here diagrams for all 1989 GMC trucks.

If you need to take apart the steering column you will also need wiring. below the color codes and wiring tips:

GMC SIERRA 1988-2005 VEHICLE WIRING

Regards.

Ginko

I assume this is a 4.3 V6? see diagram below or go to the link if u can't see the picture.

http://autorepair.about.com/library/firing_orders/bl-fo-10592.htm

believe it or not a lot of local libarys carry tech manuals. no garrentee but worth a shot

Number one should be at the 5 o'clock position. Then the plugs should go 1-8-4-3-6-5-7-2 around the cap in a clockwise direction.

Check the resistance on the coil. the (+) (-) side should be about 10 Ohms resistance and the part that goes out of the coil should be 1-2 ohms resistance. Get yourself an ohmmeter and check it. best way to check is to figure out what wire runs from the computer to the coil and follow the wiring all the way to the coil making sure theres no rips or shorts. If there isnt, then I would splice into the two wires and run two new wires over to the coil. If it still doesnt have spark then its a faulty computer and should be replaced. Good luck