Truck Won't Start With Key -- Help!

[72Much]

Ok guys here goes. I have a 72 C-10 with a 307/350 set up. I'm trying to get this truck back into service. Here's what I've done so far.

I try to start the truck with the key and nothing but a faint "click" when I turn the ket to start. The headlights come on with the switch. The solenoid on the starter has two wires, a yellow and a purple. A test light on the yellow wire to the solenoid says it has power with the key in the "on" position. The purple wire shows no light when in the "on" position or when the key is turned to the "start" position. I took the starter off and to a local store to be checked and it tests good. I went ahead and changed the solenoid thinking that it wasn't allowing the start switch to complete the circuit and it didn't fix anything. I was able to use the 'ole screwdriver from the positive battery cable over to the purple wire post to get it to start that way but my last attempt on that just clicks and sparks. I don't know what else it could be. On a last attempt I took a wire from the purple wire directly behind the ignition switch and ran it out of the cab and under the hood to the purple post on the solenoid and it still won't start that way. I'm at a loss!

Also, I found one source of the "click" noise generated with the key. It is coming from a small black box on the passenger side of the windshield wiper motor under the dash. I can actually feel the click in this box. Does anyone know what that box is? Could this be the problem?

[69halfton]

no idea what the box is... I've never heard of that sort of thing?

does your truck have some sort of kill switch/alarm system installed on it?

even if it HAS had it installed by a PO or something? could be hacked up wires causing this malfunction.

Mine had a kill switch installed by the PO and it would shut the truck off once it was warmed up, and wouldn't fire until it was cold again.. talk about frustrating problems..

if its simple enough, try bypassing this little box and see what happens.. if there is some type of alarm system on the truck.

[72Much]

Mostly original truck and wiring. No alarm system. The box I'm speaking of is right against the wiper motor. When you look under the dash it is on the passenger side of the wiper motor and it does have a few wires plugged into it.

[tranz am]

sounds like low voltage to me, either that or your starter is going out. due yourself a favor and smack the starter with a big hammer then give it a turn. half the time Ive ever done this, its worked when the starter was to blam

[rambler]

I always do the basics first.. you had the started tested, good and replaced the solenoid, but did you get a load test done on the battery? also check your ground wire, make sure it is good, and tight, how are the cables?

I've done a lot of replacing before, and found out it had a bad cell on the battery, and the lights and everything worked...

I dont know what box you are talking about, can you post a picture of it?

good luck, there are many more on this board, much smarter than me, than can help...

[nightmare]

stupid question, but is the truck in park? try holding the shift lever all the way up and try to start it.

[tranz am]

he is getting a click which tells me the starter has power and the neutral safety switch is not to blam.

Originally Posted by nightmare

stupid question, but is the truck in park? try holding the shift lever all the way up and try to start it.

[nightmare]

Originally Posted by tranz am

he is getting a click which tells me the starter has power and the neutral safety switch is not to blam.

i only posed this because it happened to me. besides, he's getting a click inside the cab, not at the starter.

[cdowns]

try cleaning both ends of both battery cables and where the four ends connect to

[tranz am]

yea i just read it again and noticed that. still sounds like the starter. even though he had it checked out, i think its still a good bet the starter is the problem. He is getting power to the starter jumping it and its still not turning over. even thou it tested good at the store it doesnt mean that the solenoid isnt going out. starters solenoids are weird about working when they want, when they get old and warn out. thats why the hammer method works. Voltage has a lot to do with this too. if the starter tester at the auto parts store is putting out a higher amount of voltage the solenoid might engage. Low voltage could equally be the cause for his problem. either way a good whack to the starter is a must!

Originally Posted by nightmare

i only posed this because it happened to me. besides, he's getting a click inside the cab, not at the starter.

[Robert8096]

It could also be that the starter is bound up and may need to be shimed. It works well when you bench test it but when you install it the clearence between the flywheel and starter gear is too close and that will cause the problem. Try loosing the bolts about one or two turns and see if that helps. Been down this road, created a few new cuss words and got the t-shirt.

[Dova]

I just went through this swapping engines. If your solenoid has 3 studs on it, try the ignition (purple wire) to the stud towards the engine. That's just a quick check. It wouldn't start to turn it over at all with that wire hooked up backwards

[72Much]

UPDATE:
Tranz Am was right on the money. I was about to flip my lid having tried everything but decided to just bite the bullet and buy a new starter. Put the new one on and it works like a champ!!

Thanks guys for all your ideas and input. It's much appreciated. But that starter testing good to begin with is what caused me alot of unnecessary headache. I will remember this in the future. Again, thanks to all.