89 gmc suburban, aps996

as far as i know the tach signal on those older autos is a higher voltage than what the remotestart module may like to  see but try the tach signal on the autometer tach if that dosen't work than you might be able to paddown the tach sinal voltage and that may work . pad down the tach signal with a1200 ohm resistereieiohztztzt

Is the unit giving you some kind of code when try to program it? Make sure the unit is tach mode and not voltage sense. Test you're tach connection at the remote start. Make sure you are getting a good signal.

I agree with mikvot on testing right at the remote start brain. That way you know your connection is good, and that there are no internal breaks in the wire. I've used a white wire behind the cluster (with Audiovox product) on those trucks, and it should work fine. You're using the APS 996's GREEN/ orange wire, right? Are you programming it like this: 1. Key on. 2. Tap valet switch three times. (Should hear short siren chirp.) 3. Key off. (Should hear loud siren chirp.) 4. Push and HOLD valet switch. 5. Turn key on, and start engine. Parking lights should start flashing. 6. Release valet switch, parking lights come on steady for a second or two, then go out. Shut engine off.

I have tried connecting at the dist and ecm and still no go. If I put it in voltage mode it starts but not on the first try. So I changed it 1.5 sec. and that is too long. Don't know how else to do. Going to see if I can find the white wire behind the cluster. I know I am programming it right. Thanks for the help. Guess I don't really need remote start.

I'm sorry, I didn't pay close attention to what year your truck was.....I thought it was like a '96 or something like that. I hope you read this before taking the cluster apart! The '89 is the older, boxier style, right? Same as, say, an '85 Chevy pickup? In that case, well, does it have a factory tachometer? If it does, there probably is a tachometer wire behind the cluster, but I've never tried it. GM usually uses white or PURPLE / white. Also, as mikvot said, have you tested for tach directly at the remote start brain? You want to put your meter right onto the Audiovox's GREEN/ orange right where it goes into the brain. That way, you'll rule out the possibility of your connection being faulty, or the wire having an internal break. Also, I did once see a mis-pinned harness from Audiovox. Compare the plug to the wiring diagram, and verify that the wire's in the right spot.

Also, I thought of one more thing. Any chance you got the ignition wire backwards with one of the accessories? In the heavy 6-pin harness, if the blue wire loses power while cranking the starter, it'll kick you out of programming. Put your tester to the blue wire, and make sure it shows power both in the Run and in the Start positions with the key.

If you use voltage on the Audiovox/Prestige systems, it is a good idea to program the voltage the same way as the tach. As mentioned turn the key on, press and release the led button 3 times, turn the key off, press and hold the led button, start the truck and keep holding and count to 15. Then release the led button, count to 5 and turn the truck off. Wait 5 seconds and remote start.

Well just about to rip it out and throw it in the lake. Don't know what to do. I have tried everything I know what to do. Thanks for the help guys, but guess I don't need remote start.