K5 will not start....

[stillyz]

First things first: I have a 1990 K5 GMC Jimmy w/ a TBI 350, 700R4, NP241, 10 bolt front(LockRight and Warn Manual Locking Hubs) and 10 bolt rear, 33" KM2s.

Last weekend, I went out wheeling with my buddies. We did some rock gardens and some trails, then I found a nice mudhole that I thought I could romp through. 33s, front locked, no big deal right? Well that hole was a lot deeper than I anticipated (originally measured ~8-10"s deep) and I sank like a rock. It was buried past the bumpers. The water and mud splashed real good, when I went in, and when momentum was stopped, I shut the engine off. I was worried that the engine may/might have sucked in some water.

After about 10 minutes of ridicule, etc, I fired up the truck (started just fine too), and my buddy in his XJ pulled me out. We continue to wheel for about a half hour or so, going up some hills and more muddy spots along the way. Truck was running well, gauges were all good too, no SES light or anything. Nothing to indicate impending doom. Then as I started to descend a hill, all of a sudden, the engine completely died.

I made it down the hill with no power, and we started to trail-diagnose what was going on. Checked to make sure nothing came unplugged or unhooked, etc. Everything was muddy as hell, but looked alright. Tried starting, nothing doing.

Checked the starter connections, banged the starter with a hammer while trying to start, still resulted nothing.

Checked the fuse block and found the computer fuse was blown. Replaced said fuse. That should fix it right? Nope, still no start.

Towed it back to the parking lot, and winched it onto my trailer.

Got back to my buddy's house, and started checking wires with the multimeter. All three starter wires have 12V of power, all the way up into the cabin. Checked all other wires that go into the cabin, all have 12V as well.

Here is what the truck does when trying to start it. I turn the key to 'run'. I hear the familiar electrical click under the hood and the fuel pump's 1-3 second buzz. The dash lights come on too. When the key is turned to start, the dash lights dim (like they would when it normally starts), but there is zero result. No crank, attempt to crank, no sound of any kind, absolutely nothing.

Also, my column shifter is totally fubar'ed. It has been since I got the truck, but that may be contributing as well. On the selector, the 'P' position performs reverse, between 'P' and 'N' is neutral, N is OD, and so on. Recently it's been a bitch to find the sweet spot of 'park' in order to be able to turn the key to start.

Thoughts? I'm about ready to take my tires and front axle and junk the thing.

 

[454Sub]

You column could not be going all the way into park, therfore not letting it start as the neutral safety switch isnt closed. I personally run a B@M ratchet shifter and never hooked mine back up, just connected the wires and now mine starts in any gear i want it too, you could bypass it just to see if that is your problem as well. Try starting it in neutral and see if it starts. If not, maybe your battery connections are loose, or have water in between the ground strap to the frame or block, try taking them all off and cleaning all of them up, even at the starter. Maybe take the starter and battery up to your local parts house and have them tested, its free and all this is easy to do and free, dont just throw money at it to fix it, thats expensive.

 

[stillyz]

I've got a suspicion that it is the shifter, and that it's not going all the way into park. The shifter you mentioned looks legit, but my Blazer is clapped out, body-wise. I don't want to sink much money into it, but if it's something cheap/easy, I'll check that out.

I checked everything (visually) and made sure everything is tight with the starter, and everything looks good. I also confirmed that the battery connections are tight, and I tried jump starting it today, no luck. There were some sparks when I connected the negative terminal, which means that there should be juice flowing. And the battery is about 9 months old, DOM-wise. I purchased it in January 2012.

 

[stillyz]

You column could not be going all the way into park, therfore not letting it start as the neutral safety switch isnt closed. I personally run a B@M ratchet shifter and never hooked mine back up, just connected the wires and now mine starts in any gear i want it too, you could bypass it just to see if that is your problem as well. Try starting it in neutral and see if it starts. If not, maybe your battery connections are loose, or have water in between the ground strap to the frame or block, try taking them all off and cleaning all of them up, even at the starter. Maybe take the starter and battery up to your local parts house and have them tested, its free and all this is easy to do and free, dont just throw money at it to fix it, thats expensive.

Do have any idea how to bypass it?

I have tried starting it in neutral, but the neutral safety switch won't allow the key to be turned all the way to start.

 

[454Sub]

If i remember correctly, its only a 2 wire thing shaped like a half moon (best way i can describe it) on the bottom of the steering column, just hook the wires together and it should be bypassed

 

[Jester1]

With hitting the mud hole hard enough, and the mud drying as he was driving could it have cemented some of the shift linkage to the point of breakage? Or at least causing the neutral safty to not work?

 

[454Sub]

I kind of find it hard for the mud to have broken the NSS like that, it just works off the column moving a tiny linkage inside the truck. Maybe see what the starter wires have when you are actually cranking it over to test for voltage drop, im still thinking either electrical ie battery, starter, or cables in between, or the NSS itself because the column is bad.

 

[rebelgregory]

I feel like maybe there's a piece of the puzzle that's being ignored. Yeah, it won't restart, but what made it cut off in the first place? And what blew the ecm fuse? Fuses blow when too much current is drawn across a circuit.

You may want to separate all of the wiring connectors that fell below the water/mud line. If water gets into your connectors, it will have a hard time evaporating. In the mean time, it's corroding the prongs inside. Water in there will cause a short between the different prongs and if a hot wire is connected to a ground by water...boom goes the fuse.

I don't have a wiring diagram in front of me, but if you can find one and look at the distinct circuits in the ecm fuse path, you may be able to narrow it down IF this is in fact the problem.

This is just my $0.02 and a place to start, but the shift lever wouldn't cause your truck to die while running. A blown ecm fuse will. IMO, I would chase that gremlin first. Good luck. Let us know what you find.

 

[bradshawtech]

I am not sure what caused the fuse to blow but another test would be to turn and hold the key in the start position and then run the shifter through the gears to see if as you pass the park and neutral position it may try to start or at least hit the starter for a moment.

Be prepared with the brake applied so if it starts in a drive gear position it won't take off on you.

If his column is messed up then it could have the ignition switch down on the lower part of the column moving around and when he was heading down that hill it moved and killed the engine.

 

[Jessie James]

Here is a simple trick:

1. Turn on the ignition.

2. Jump the starter terminals with a short screwdriver or something metal like a key. Beware of grounding out the battery wire to the block or starter housing! You will probably see a little spark, but it's not a big deal.

3. The engine should turn over. If it does, your starter and battery are fine. If it doesn't then either you have a dead battery or dead starter.

You want to use something beefy, but not so long that you accidentally ground it out. All you have to do is jump the big wire from the battery that is bolted to the starter to the smaller solenoid wire, which is usually the only other wire on the starter.

This should at least tell you if the battery and starter are okay, regardless of your park switch.

 

[chadepperson99]

Not trying to highjack anyones thread but I have a similar problem that I need some help with.

Hello, I am considering buying a 91 k-5 blazer, I found one for 2000 with no rust which is pretty rare here in northeastern oklahoma, but the owner has tore into the column and tried replacing the ignition switch, and the turn singal, cruise conctrol switch. He claims the truck ran great before he tore into in, but now he doesn't know how to put it put together and so now it won't start. My questions are is there a quick way to wire around the switch to atleast make sure the motor is good, and how hard is the other suff to replace, I have always done all my basic maintenance to all my cars and trucks (this would be my first K-5), so I consider myself pretty good with a wrench, any and all comments would be greatly appreciated

 

[Jessie James]

Chad, you should start a new thread if you haven't already. It gets too confusing trying to answer two problems in one thread.