Hi everyone, I have a 1973 Ford f100 that i swapped a 302 that i rebuilt myself and a Borge Warner t18 4 speed transmission out of a 74 f100 into. new starter, distributor, coil, plugs, plug wires its all new. it has a point ignition system which is stock to the truck but not the engine, i just bought a new distributor that was a point. but for whatever reason when I turn the key nothing happens, no noise of the engine or solenoid nothing, but the dash lights and everything turned on. i know its not the starter because when i jump the solenoid the engine turns over great with no problems or odd noises. i replaced the solenoid and now the battery trying to find the problem but no luck. i didn't do any work to the wiring harness at all just unhooked it for the swap but its all in exactly how it was before and the key worked fine on the old engine, which was a 240 six with a c4 auto. it may have something to do with the new engine not sure. please help me or let me know if you've had similar problems please.

Ryan

 

It will take some step by step trouble shooting to find the problem. Good news is the battery, starter and solenoid seem to be in good shape since it will crank when you jump the solenoid. The wiring between the switch and solenoid is the problem... or maybe the switch itself.

As a first step, suggest you determine if the key is powering up the ignition coil correctly. Turn the key to run position and put a test light or voltmeter between the coil positive terminal and ground. You should see voltage there... maybe not a full 12 volts but at least 8 or 10.

 

Sounds like the neutral safety switch is unplugged since you swapped transmissions. Not exactly sure on your 73, but on the later trucks there is a jumper plug that goes into the harness where the NSS switch on the auto transmission would plug into.

 

Agree with redmt79 on the NSS.

 

Wiring isn't my strong suit but you could try bypassing the neutral safety switch and see if that works. My truck doesn't have the neutral safety switch anymore because it was giving me issues when starting.

 

thank you all for the quick replys I'll definatily start to try some of those things. i don't think it has much to do with the tranny because when I took the old one out there was no wiring too it but I'll still look into it. also thought that the truck may just be grounded bad all together so ill start looking. thanks again

 

Neutral safety switch +1

However IIRC the automatic trucks had the NSS as part of the column shifter/gear selector assembly and not attached to the transmission? It can still be jumped and bypassed, just have to dig a little to get to it.

 

Did you do anything with the steering column? If your automatic transmission did not have a switch and harness attached, then the NSS is probably on the column as mentioned above.

Now keeping in mind that you swapped to a manual transmission, if you did not swap the steering column, make sure the automatic gear selector is in Park (or neutral) in order to start the truck. IF you did swap to a manual column, then the wires in the original NSS harness plug need to be jumped.

 

Also make sure the lil wire on the solenoid is still attached.
There should be an I and an S on the fender mounted solenoid. The original push on wires have a tendency to fall off if bumped.

 

Yes i kept the old auto steering column because the one off the doner was manual steering. ill go try and shift that into park i never thought of that at all. thank you guys. but for the future, how do you bypass the neutral safety switch?

 

Nope, shifting the column into park or neutral didn't do it, i notice my voltage was kinda low to the coil only about 2 volts with 10 on the battery. i do have a ballest resistor hooked up to it its a 1.6 ohm not sure if that's causing a problem or not...

 

Thought I read somewhere recently you need 8 - 10 volts at the coil but I don't know if that is a hard fast rule for every engine application or the one I was reading about, sure sounds low. Battery voltage is pretty low regardless.

 

Agreed....10 VDC will not start yer vehicle. Charge the battery. Then if you still suspect the ballast resistor wire, measure the voltage from the + coil to ground with the key ON, engine OFF. You should read between 6 - 9 VDC if it's good.

 

For sure charge that battery. 10v may not even be enough to trigger the solenoid. But do leave the column in Park to eliminate the NSS issue.

 

i found the NSS it wasn't attached to the column so ill bypass it and charge the battery, thank you.