HELP, my truck will not start

[EOliver]

HELP, my truck will not start...now I am stumped

1. OK guys, here is the deal...



I ran down this morning and she fired right off just like normal. I ran back in the house, grabbed my coat and all the other junk I take with me every day. I got back to my truck and unplugged the heater, jumped in, put all of my stuff on the seat, turned and closed the door. At this point I saw the brake/ABS lights flash on the dash and then my truck died, just like I turned off the key. Now everything seems to work ... EXCEPT the ignition switch. I turn the key and nothing happens, no radio, no clicks, nothing... (the buzzer still works if the key is in and the door is open) Lights still work, battery is still connected, all wires that I can see look ok. I didn't have any electrical smell or smoke, so I am hoping it's something simple. Could it be the ignition switch, or should I check other things first?



I don't know where to go from here, I checked the fuses under the dash, but what else??????



2. OK I have spent an hour or so digging around in the steering column and under the dash... no blown fuses, battery is at 12. 30 volts getting 12 volts to the ignition switch, and to all non-switched accessories. But when I turn the key to ON or to the ACC position it stays the same no power to anything that the key turns on. I am gonna call around and see if I can find an ignition switch I guess.



3. OK got an ignition switch... . guess what... . it didn't fix my problem, truck still dead. I don't know what else to try... . H E L P



Thanks for any input fellas

 

[CToney]

Won't Start

My only guess might be a bad ground somewhere or a relay that has gone south. Check all grounds with starter and battery for corrosion and looseness. Also don't leave your truck's block heater plugged in while its running the vibration while it has electricity shortens its life span.



Good Luck



CR Toney

 

[Lil' Dog]

Check the power to the fuse panel, there may be a fusable link that has blown under the hood. There are a couple of fusable links on the drivers fender near the firewall.



Maybe someone has a manual to show the exact one to check...



J-eh

 

[EOliver]

OK I went and checked all the ground connections I can think of. They all look good, and are tight, I checked most of them with the ohm meter and they measure zero resistance. I can only find three relays on the drivers side inner fender , but I don't know what each one is for. I know the big relays for the intake heater, but there are three small ones attached to the fender. I am off the the dealer to find out what these relays are.



Wish me luck...





Come to think of it a fusible link could be the cause, but I don't have a service manual (yet, dang!) If someone has a manual could you please let me know if there are any fusible links and where they are?

 

[KEENO]

3 relays...

Hey Eric!



On 5 spd trucks the (3) relays are as follows if viewed from the front looking rearward along the inner fender.



1st relay = Fuel Pump



2nd relay = Starter



3rd relay = A/C compressor clutch



I hope this helps...



KEENO

 

[EOliver]

Thanks, Keeno



I am going to go get a relay and see what that does for me, if that doesn't do anything I guess I will start digging into the wiring harness to find those god awful fusile links.

 

[ETOBICOKE]

Ignition switch

Eric the ignition key switch has 4 seperate circuits. One circuit is grounded only in the start position, this is only for the lamp check. The other three are ahead of the fuses and protected by a fuse links. One circuit is for the starter and acessories, the second is the A/C and power windows and the last goes to the computer, auto shut down relay(alternator), fuel heater and injetor pump solenoid.

My guess based on what you have posted is a burnt fuse link. Have a look under the hood on the drivers side inner fender, near all the relays you should see a wiring harness. At this point some of the wires exit the harness, these are the fuse links. They are easy to tell apart from the normal wires as they have rubber insulation and have heat shrunk insulation at each end. What you need to do is gently stretch each one, if its bad it will come apart easily. Replacement fuse links are available from the auto parts store, you must not use regular wire for a replacement.

Hope this helps, if not and you need wiring diagrams, send me an email.

Neil

 

[EOliver]

OK based on the description of the fuse links, they are obvious. I will check them next, the relay was NOT the culprit... .



Thanks everyone!

 

[EOliver]

Here is what I have found... 2 bad fuse links maybe 3, I replaced 2 with ATO fuse holders and put in some 30 amp fuses, but one blows when I turn the key to the run position. (I have a short in one wire somewhere) The fuse links all look to be in bad shape. I would like to replace all of them, but do they have to be fuse links, or can I use regular ATO fuses in weather-proof closures? I hav never been a fan of fuse links, plus it would be nice to know that the spare fuses I have in the glove box could fix it again should it decide to go south. So in the morning I am off to get some wire, and more electrical stuff, and then trace the wire that is blowing the fuse. (never ending fun)

 

[BushWakr - RIP]

FWIW



Seems to me I read somewhere in the serv. manual that the block heater should NOT be plugged in when the truck is started. Now, I'm not sure if I'm just hallucinating on this or not so I'll grab the manual and have a look. Someone else suggested that it was possible to do damage, what, I don't know. I can't figure how a closed circuit like the block heater would be a problem since there is no direct contact between the individual components even if it is run off 120V AC.



I'm off to look this one up... ... .....



Regards, Bob

 

[Jim Fulmer]

BushWakr

I remember back in the day when I drove a cummins in the oil field it was a rule that you never started the truck with the block heater plugged in, it burned it up everytime... ..... been there and I remember.



Jim



EOliver sorry for your troubles but now you are our learning tool buddy!

 

[Lil' Dog]

Blockheater

The element in the block heater vibrates and breaks. The running doesn't hurt the block, just the heater.



J-eh

 

[EOliver]

OK guys here is where I am at. I have traced the wire that was blowing the fuse. It goes straight to the rear terminal of the ignition. When I turn the key to the run position this terminal goes to ground. I am back to thinking this is the ignition switch again. But last time I tried the ignition I had a couple of bad fuse links. Now that I have power getting to the ignition again, I think I will try that new switch again.

 

[Nordby]

I have a manual down in Monument Colorado you are welcome to borrow if you need.



Jon

-- email address removed --

 

[Extreme1]

Straight to ground...

Check the Auto Shutdown Relay. If the coil shorted out (straight to ground) it would kill everything. I don't think it would affect the starter circuit though...



Hmmmm... .



It might though, depending on how it is wired. Can one of you guys post a scan of the wiring diagram with the ignition switch?

 

[JTroiano]

Unplug as many circuits after the ignition and put a new fuse in and then plug one circuit in at a time until it blows and then break down that circuit until you find out what is causing the short. Just pray it doesn't fix itself or you won't find it until it shorts again. hope this helps.

Jon

 

[Matt S]

EOliver

Did the new ignition switch fix the problem?

 

[EOliver]

OK guys, sorry it took so long to get back to you all. I found my problem, and fixed it on Wednesday. (Neil, thanks for the wiring diagrams!) It was a shorted wire that goes to the fuel pump. Just an FYI for all you guys, check your wiring harness where it comes around the brake booster to the fuel pump and make sure that the harness is NOT rubbing on brake booster! So my truck is back on the road again, wow what a pain in the butt.



THANKS EVERYONE FOR ALL THE HELP!