Starts only after letting off on ignition key. If I keep the key turned it will keep cranking but not start. Depending on how cold or warm I have just about figured out how long to let it crank before letting off on key so it starts right up but know I need to fix it. PO replaced electronic ignition so no telling but seems like it would be a wiring issue?

 

It's most likely your ignition switch but could also could be the 12 volt feed from the starter relay "I" terminal is not doing its job....broken wire or bad contact in the relay.

The relay supplies 12 volts to the coil + during starting......so if it is missing the engine wont have spark when the key is in the "start" position but will spark when released to run.

Easy check...jump 12 volts to the coil + and try and start the truck...if it fires up that is the problem.

Now remove the little wire from the "I" terminal of the relay and jump the 12 volts to it......try and start the truck again...if it starts fine the wire is good and the relay is bad, if it doesn't start then the wire is broken or corroded somewhere, the wire runs from the "I" terminal direct to the coil +

If all the above tests pass muster suspect your ignition switch.

 

Sounds exactly like my issue and pretty easy to test, I will check it out and report back.

Thanks!

 

Okay, bear with me electrical is pretty much a mystery to me. Had a couple of minutes at lunch so thought I would fiddle a little. I diosconnected the "I" terminal form the starter solenoid/relay and hit the key started right up firing when key was on as it should. Reconnected the "I" terminal and still works as it should! Am I nuts! Maybe a short in the relay? Should it run at all with the teminal completely disconnected? Will have more time for investigation this weekend, any thoughts?

Thanks!

 

Mine was doing the same exacted thing yesterday. Ended up bein the wire that goes to the s terminal.

 

Mine was doing the same exacted thing yesterday. Ended up bein the wire that goes to the s terminal connector bein loose. Easy fix.

 

A PO must have some very "creative" wiring going on there...

When the key is in the "Start" position the only wire that has power from the ignition switch is the wire to the small "S" terminal on the starter solenoid, when power is applied to the "S" terminal, the starter solenoid closes, when closed the large terminal to the starter and the "I" terminal to the coil gets power, there is no other power going to the coil.

When the ignition switch is released to the "Run" position there is no longer power to the "S" or the "I" terminals and the solenoid is now open and the starter is also no longer cranking, power to the coil has now shifted, through the ignition switch to the resistor wire.

 

Like montanaHB said, its either some hackjob wiring, or I'm wondering if when they replaced the starter relay if the messed up re connecting everything.

 

Not surprising considering what else I have found since getting it home.

Going to try Montana HB's test this weekend and also see what I can do about confirming correct wiring or lack there of.

Thanks

 

Took off early from work to run the test on the relay as recommend and found out some extra info. Probably should have mentioned it has electonic ignition I believe from the factory since the valve cover sticker says point gap "none" and dwell "none" regardless it has an msd on it now. The relay was what I expected but the 'I' teminal runs into the firewall not to the coil.



The MSD has (2) wires to coil and (2) to the dist. as far as I can tell from MSD diagram online this is correct. where it gets sticky is

This second? relay is located below the MSD anyone ever see something like this? I originally thought this had somethig to do with the Camper Special second battery but now I don't know.



Sorry for rambling and I do realize this is, as was mentioned earlier a hack job of wiring and I wil eventually get it cleaned up but need this truck running.

Big question is what would most likely make it fire occasionally when key is on as it should maybe 5-6 time in a row and then go back to firing after letting off with no changes? I would think a short or bad connection but really not sure what to check. If the principle is the same as what Montana HB was suggesting should I run a wire from msd to + on coil and see if that works? sorry for being such a but the last thing I need is to fry something. Other thought is to replace the ignition at least I would then know that is good. oh yeah forgot to mention found a kill switch (glad the PO told me about that one!) but it seems to work, runs in one position not in the other so don't see how that would be an issue.

I know but feels good to vent!

 

Thought I would update this old thread with some good news. Not the best method but started replacing parts as it was easy for me to do and not as expensive as doing a bunch of testing which I am not that good at anyway.
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New solenoid and coil installed and also checked and cleaned all connections at battery, solenoid, starter, ignition (msd) - no change<O></O>
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Key was sticking and really worn so next was a new ignition switch and lock barrel – no change (but shiny new key)

While checking connections found missing ground from block to frame and corroded ground from intake to firewall. Replaced neg and pos cables neg to block and then used a bat ground cable to go from block to frame. Replaced corroded wire at firewall with braided cable. – no change
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Seemed maybe it was module related so started researching msd set up. <ST1PO </ST1had installed a kill switch incorrectly so wired up the kill switch per msd instruction and then got a new coil connector (which was missing) and wired the msd directly to that which turned out really nice. – no change<O</O
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Originally truck had the dual battery set up and currently has the second relay getting power from the starter solenoid which the msd was hooked to, seemed alright but as I looked into the msd trouble shooting guides (internet is awesome) kept coming back to “losing ground or power” so checked location and condition of ground still no change.<O</O
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Ran msd power directly to battery and BINGO! fired up with the key turned to start just like that! MSD says the connection directly to the pos terminal is optimum but I thought it was a cleaner run to go to pos side of solenoid which seemed to work just as well so I am going that route.<O></O>
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Probably could have fixed it by reading the MSD instructions and checking <ST1PO</ST1’s install of ignition but hey got lots of time under the hood and cleaned up a bunch of junk at the same time!<O</O

 

When I installed the MSD on my truck, I was looking to bypass the stock ignition wiring as it is old and brittle and I was having trouble with the duraspark system. I wired the large red and black MSD wires directly to the battery terminals. I ran a wire directly from the ignition switch to an add on fuse block and connected the smaller red MSD switched 12 volt wire to it.

My truck had a similar situation where it would crank but not run when the key was turned to the "start" position; however it would start if you turned the key to the "on" position and used a starter switch jumping from the positive batter terminal to the "s" terminal on the solenoid. I checked and the light on my MSD box was not lighting when cranking with the key. To correct this, I ended up purchasing a Bosch SPDT relay, PN 0332019150. I ran a wire from the switched source fuse box to the normally closed terminal, ran a wire from a direct to battery add on fuse box to the normally open terminal, ran a ground wire to one side of the electromagnetic switch, ran a wire from the "s" terminal on the solenoid to the other side of the electromagnetic switch and connected the red switched source wire on the MSD to the common terminal. Now when the you turn the key to "on" the MSD has power through the normally closed terminal. When you turn the key to "start" and power is applied to the "S" terminal on the solenoid, the switch inside the relay is activated and the relay switches from the normally closed terminal to the normally open terminal. This now draws power directly from the battery to power the MSD. Once the engine fires and the key is released, the relay switches back to the normally closed position and draws its switch power once again from the ignition switch.

I got this idea from a book on car electronics I have that described how relays worked and took the mysticism out of them. Once I added the relay, my truck starts awesome and I don't have to worry about getting out and jumping any connections. If you are interested in what I did, I can provide a pic or two and a diagram. The relay was about $17.00 at a local automotive parts supplier and the two fuse boxes were about $10 each at AutoZone. I already had ATC fuses and wire so no cost there.

 

That set up sounds like it would clear up several issues, I may ask for those pics in the future but right now I think I am going to see how it works as is for awhile. There is still a rat's nest under there from some PO creative wiring. As time permits I am going to trace everthing and try and figure what is what.

Thanks!!

 

No problem, just let me know if you do. The MDS documentation says it does not need a fuse since it is internally protected. However, I still used 30 Amp ATC fuses in the fuse boxes to match the rating of the relay for protection. I also took advantage of the ignition kill feature. Since I have an MSD distributor, I used the grey wire and ran it inside the cab to a nice looking rocker switch. I then grounded the other terminal of the switch, flick the switch up and it runs, flick it down and it doesn't. The previous owner put daylighters on it and already had a bracket in place for the daylighter switch that had a second empty hole. I took advantage of this and placed my kill switch there. Now I have a slight theft deterrent and an easy way to kill the ignition if I need to bump the engine without having to disconnect the coil wire and/or hook up an external switch. If you want pics of that too, just let me know.

 

Will do, I setup the kill switch also, mine is concealed up under the dash. I don't use it much but what the heck it was easy and I figure if I ever leave it parked for an extended time that combined with the locking hood latch give me a little theft protection.

Thanks again!