Top 10 1989 GMC Sierra Questions & Answers

if it has a 4.3 liter motor a 86 to a 97 if it has a 350 motor a 81 to a 96 will work hope this helps

Look up under dash where brake pedal pivots, you should see a switch that is activated by pedal arm.

It Should be located some where on the driver side in the wiring harness maybe tucked back in or some one could have cut the wire

Disconnect the battery for a minuit and turn on the light's to power down any electrical power. Reconnect the battery and that should clear the "servie engine light soon",but if there are any DTC codes, the "Service engine light" will come back on.
On board diagnostic (OBD) was designed on vehicles equipped with electronic fuel injection so you can generally retrieve the codes yourself. No need buying a scanner or running to any parts stores to check the Engine Light. This system is called obd1 and applies to most vehicles made before 1995 for domestics and 1993 on imports.

For GM domestic vehicles made before 1995, the diagnostic connector is located under the dash panel by the driver side. To get the check engine codes to flash in your dash panel, use a jumper wire or a paper clip and connect terminals A and B of the diagnostic connector. Turn your ignition key on with engine off and the codes should start to blink. All codes should start with code 12 which is one long flash followed by 2 short flashes. This code 12 means the diagnostic system is normal and will repeat itself continuously if there are no trouble codes. Otherwise, code 12 will flash 3 times before flashing the fault codes.

the codes can be erased or cleared by disconnecting the battery negative terminal for 1 minute and reconnect. Just make sure to check your service manual in case you have electronic equipment such as radio or clock that needs reprogramming in which battery disconnection is not recommended. Finally after performing repairs on the culprit code, always go for a road test to confirm if the problem is fixed.

Good luck and hope this help, here is a link to the DTC codes. http://www.gmtuners.com/OBD1_DTC.htm

there is one under the hood the other is tucked up under the dash or behined a panel on the side of the dash with door open.

HI. This issue has many causes. i will list the most common causes below.

Coolant consumption::: Possible causes______


1. Check the head gaskets. The gasket may be leaking.
2. Check The Intake Manifold Gasket. This gasket may be leaking, worn, or damaged
3. Check the cylinder head for worn or scorn cylinder block.(This will require total breakdown of the engine)

4. Check the water pump seal for leaks as well.

Now that we have covered the basic check points for coolant consumption, i would advise to concentrate on the head gaskets if there are no apparent leaks on or around the engine itself. If the head gaskets are worn, the leak can be introduced to the engine internally, causing the engine to burn off the coolant. this is noticeable by removing the oil cap, after a hard drive. you Will notice steam that will escape the head as soon as you remove the cap. If this is the case, your problem will be with a failed head gasket.

IN a severe case, you will notice white plums of smoke escaping from the tail pipe during acceleration.

actually that first soultion is wrong it is correct on smaller pickups but on the full size pick ups they use a differnet sytem
there a electric actuator on front axle
there be two elctrical plugs on front axle u want the bigger of the two other one is just to turn the 4 wheel drive light on
un plug actuator then remove actuator after it removed plug it back in but leave it out of axle turn key on and shift down to 4 wheel drive the actuator should move out if it dont that your problem if i does move this isnt your problem it either the tranfer case or in front axle

A.T., VIN model "C" (4x2), TH400, 6 cyl
A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-305 (5.0L)
}A}}400}466495" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-350 (5.7L)
}A}}400}466496" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-379 (6.2L, diesel)
E>}B}}400}466497" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH700, diesel
A.T., VIN model "K" (4x4), TH400, 6 cyl
B@}}}400}466499" type="radio" name="userInterchange" />A.T., VIN model "K" (4x4), TH400, 8 cyl, diesel
A.T., VIN model "K" (4x4), TH400, 8 cyl, gasoline
A.T., VIN model "K" (4x4), TH700, diesel
FFC}B}}400}466502" type="radio" name="userInterchange" />M.T., 4 spd, 4x2, VIN model "C"
FFC}A}}400}466503" type="radio" name="userInterchange" />M.T., 4 spd, 4x2, VIN model "R"
ECB}B}}400}466504" type="radio" name="userInterchange" />M.T., 4 spd, 4x4, (VIN model "K")
M.T., 5 spd, 4x2
M.T., 5 spd, 4x4
A.T., VIN model "C" (4x2), TH700, gasoline
F=A}B}}400}466508" type="radio" name="userInterchange" />A.T., VIN model "K" (4x4), TH700, gasoline
}B}}400}466509" type="radio" name="userInterchange" />A.T., VIN model "R" (4x2)

Check your emergency brake. Make sure it isn't partially pressed in. Try unplugging the switch to the emergency brake and see if the light goes out; if it does the switch is bad.

There is a short on the horn circuit