Engine/Transmission (1994 - 1998) no start after conversion?

[98slushbox]

I recently completed a transmission conversion from a manual to an auto. When i went to start it for the first time it wouldnt crank. Wondering if someone could give me an idea of what i may be missing. The one thing that i know is not hooked up is a round plug on the side of the trans. It has three prongs but dont know what it is. It seems to be busted and will need replaced. I dont know if this would cause the no starting problem. Any help would be appreciated. thanks,

Lance

 

[bmoeller]

Is the starter turning the engine over? Need more details.

 

[6BT-Dakota]

You need that plug. I believe it contains the neutral saftey switch and the truck prob wont start without it if you have everything else hooked up properly. Get yourself a wiring diagram and you will see everything it does.



Rob

 

[BigPapa]

Get in contact with Dieseldemon. If it's a wiring thing, he can help you.



Scott

 

[98slushbox]

The truck wont turn over. figures that the only plug i am missing is the one that keeps it from starting. I will send dieseldemon a pm and see if he can get me straightened out. thanks,

Lance

 

[Howard Durand]

As Rob said, you need that plug. A switch in the transmission prevents start unless it is in park or neutral.

You can try grounding the black wire to test the start process but then it will start in any position of the shift lever so be careful.

There was a clutch pedal interlock switch with the manual transmission. Make sure it is closed.

 

[98slushbox]

Do any of you guys just happen to have one of those plugs just laying around? I tried closing the loop on the old clutch circuit but didnt help without the auto. trans plug connected.

Howard, I see your truck info. says TPS removed, i'm assuming thats the throttle position sensor? Thats something I also have to install yet. Is there a way around it, because i dont see where the bolts go onto the side of my pump? thanks,

Lance

 

[Howard Durand]

Lance, you probably don't have the necessary hardware for the TPS on that truck if it originally had a manual transmission. There may also be a problem if you have the original PCM. You should talk to someone that has made this conversion to be sure you have everything that you need. Replacing the TPS is easy and inexpensive if it will work with your PCM.

 

[pwerwagn]

I tried closing the loop on the old clutch circuit but didnt help without the auto. trans plug connected.

You also need to complete the circuit at the neutral safety switch. I have done this many times when the switch went bad, or broke, or whatever. All my 727's now have the neutral safety bypassed.

I usually use a jumper wire in there, find the two that need to be jumpered, and then cut the plug and splice them together.

oh yeah, it will now start in gear after this as well (as mentioned in a previous post), so be careful with it!!



--Jeff

 

[98slushbox]

I have swapped over the pcm and the whole wiring harness so the plug is there for the tps. I have a tps already also. Thanks for all your guys help. It worked jumping the switches out. I was able to start it and get it out of the shop, but i will get the plug anyways just so its like factory.

Lance

 

[Redram 1]

re

call Ryan at Ryans garage he has the parts you need,He does those conversions all the time.

 

[Howard Durand]

Lance, If you have the TPS connected, just tie it up so it won't flop around and try driving it. It should behave just like the potentiometer that I am using except you won't be able to adjust it.

If the signal voltage is somewhere around 1 volt, it should shift into OD at about 30 mph and TC lockup shortly after that. You probably won't have kickdown capability but that has not been much of a problem with these buggies.

If that works, and you want the 3-4 shift to come at a higher speed, manually rotate the inner part of the TPS and use some sort of clamp to hold it in that position.

Howard

 

[98slushbox]

Redram, do you have the number for ryansgarage?

Howard, I havent tried driving it down the highway yet, but i'll give it a try. without kickdown, i'll just have to man. downshift if needed? I put in a ratchet shifter so thats not a problem. should be fun to use. What about the O. D. on/off button. Do i need to splice one in and mount it somewhere?

Lance

 

[Howard Durand]

I think you will want an OD off switch. It would be nice to have the original button that includes the light but you can make up one from any momentary switch and an LED.

If you have the wiring harness, it probably has the receptacle for the switch.

If so, the switch would connect between pins 1 and 2. #1 is grounded, #2 connects to PCM pin 10. .

The light would connect between pins 3 and 4. Pin #3 is positive pin #4 connects to the PCM at pin 37.

Wire colors for the switch are as follows: Pin 1 is black/orange, pin 2 is orange/white, pin 3 is Dark blue/white and pin 4 is light grey/orange. Pins 5 and 6 are not used. If you want to use an LED, go to Radio Shack and get an assembly that includes the built in resistor. An ordinary LED cannot take 12 volts, it must have a resistor in series.

The switch should be momentary so that it toggles the PCM each time you operate it.

 

[98slushbox]

Howard,

Well, i had bought exactly what you just explained, but now that i have it running and driving, i ran into yet another problem. It wont shift into O. D. Now that i have discovered this problem, I figured i needed to wire up the od on/off switch, and since i found a local truck being parted out, i went and got the factory switch off of it. I put it all in and still the same problem exists. The only thing i can think of yet is the speedo sensor. My wiring speedometer plug wont plug into the sensor. Im not sure why, cause i swapped the wiring harness to an auto harness. I was thinking the pcm needed a speed signal? I havent gotten my tps hooked up yet either. Any ideas? thanks,

Lance

 

[Howard Durand]

Lance,

I am not sure about the speed sensor. It may be important but I am quite sure you need a signal from the TPS. Maybe you can get the bracket for the TPS from the same vehicle you got the switch.

Meanwhile, just plug the TPS in and tape it up so it can't flop around and see what happens. I have never tried that but it will provide a signal voltage and should allow a shift into OD.

Howard

 

[Howard Durand]

Also, you will need a transmission temperature sensor or resistor to replace it with.

 

[98slushbox]

I have the tps plugged in and laying on the fenderwell, but no luck with that. I ended up getting the factory lines to work so i have the oem temp sensor hooked up. The motor on the truck i was getting parts off of was used on a chevy conversion so the tps bracket is gone. I guess the next thing to do is get the correct speedometer sender. Must be different between years. The guy that had this trans originally said it was running and driving, but got wrecked or the motor was burned. He has always been a honest person, so i'm taking his word the transmission is good.

 

[Howard Durand]

You can make up a control switch to manually operate the TC and OD. It is pretty easy to do. But first take a volt meter and check the center wire of the cable that plugs into the transmission. It is light green with a black tracer. With the ignition switch on, you should have 12 volts between that pin and ground.

You can also check the solenoids with an ohm meter. With the cable unplugged, on the transmission receptacle measure between the center pin and each of the two outside pins. They should be about 30 ohms each. None of the pins are grounded at the transmission. The PCM is the ground switch for both the OD and TC solenoids.