20 Most Recent 1989 GMC C1500 - Page 4 Questions & Answers

first is the truck automatic? or manual transmission, this information is important to know because the neutral switch on the automatic plays an important place on the starter circuit, and on the manual trans, the clutch switch does the same, also make sure you have not aftermarket alarm on the truck because that will interfer with starter cicuit, and to test the ign switch just test every wire close to the swtch and you suposed to get power at least on one cable while trying to crank it,

Might be caused by tranny filter being dirty

it's the connector tape on main harness it could be Inside isolator

Hi, P0122 code i think reads as "low input" on the fault text, if thats so, the fault is most likely with the wiring to/from the tps, low input codes would usually relate to a short on the wiring so check for any chaffing or corrosion on wires and multiplug connectors, ideally you need to check voltages at the tps connector.

Chevy 2500HD No Start No Spark No Fuel Cranks OK Testing !!!

Have you tried replacing the fuel pressure regulator in your EFI (carburator) Sorenson sells a kit that has all the gaskets, screens and regulator for around $30.

Blend door motor not working properly.

Are you sure this is your problem? I don't believe passlock connects to the pcm. It usually goes thru the bcm to disable the start relay.

Sounds like you replaced alot of parts for nothing.The pickup coil in the distributor "fires" the module which grounds the coil and the injectors.Those components would need to be tested. The coil fires the plugs when the ground is removed by the module or the key switch.

In the bottom tube of the condenser core. Remove the grill and the tube that comes up at about 60 degrees on the condenser. If you look closely at the tube you will see a small dimple about 4ins along from the connector. That dimple is what stops the orifice tube from traveling further down the condenser tube.

crank fuse has only power while cranking and it's from the ignition switch.

The "A/C" Fuse, a 25A fuse, controls the A/C and Blower Relays. Pulling this will remove power to the blower motor.

IGNITION TIMING

1997 GMC Truck C1500 1/2 ton P/U 2WD 5.7L SFI 8cyl

The Ignition Timing Non-adjustable.

find out if you have fuel pressure all the time while cranking hope it helps

Clogged cats in the y-pipe

Wheels.com

As long as they are 15's then your golden