Truck Mechanics need help

What is the name of this canister that an electrical plug is plugged into? Having a no crank issue with 07 Silverado, this canister is making a sound each time we try to start the truck.

Thanks a bundle!!

That's the 4x4 actuator. It is probably until locking when you turn the key on.

anything out of the starter? does it crank?

Ok. Yes Treedablackdog, I just replaced starter. I can get starter turn crank from relay by jumping with a jump wire. I think the problem is somewhere between the ignition switch (which is new) and the starter relay. I have power at the starter relay from battery, but no power any where else at the starter relay when we turn the key on.

Does it start in neutral?

No. will not crank- any help would be appreciated. Thanks guys.

Just a shot in the dark here, is it possible that the shifter safety switch is bad??

Can you get ahold of/buy a cheap code reader?

Replaced starter what about solenoid that you are jumping.

Ok so you are actually jumping the relay under the hood in the relay and fuse box ? It sounds like if you are jumping the starter solinoid you could have a bad fuse or even a bad wire. I ha e seen the wires that all go to the starter carode pretty bad up here but that's cause we use a lot of salt in the winter. So I would check the wiring and make sure it's all good

I don't have a clue why ignitions have to be so complicated. clutch safety switch, neutral safety switch, anti theft proper key cut off, low voltage relay, and who knows what all anymore. a solenoid between the starter and the switch, hot wire to A coil worked just fine. didn't need to be a rocket scientist to diagnose whatever the problem was. a tach/ohm meter, a test light, compression tester and vacuum gauge were enough to diagnose any problem on any vehicle.

anymore I take most problems to a shop

There is a pink wire that comes off the ignition switch, should have 12V with the key in the start position. Pink wire goes to the body control module, connector X1 pin 2. ( I know the connector and pin numbers probably won't help you, but you may be able to look them up). BCM talks to the PCM over a network and tells it that the key is in the start position. PCM sends 12V on a yellow/black wire, connector X1 pin 71, to pin 86 of the starter relay in the underhood fuse black. The starter relay coil is grounded (pin 85) at the engine. The switch side of the starter relay should have power with the key on at pin 35. Pin 87 should have power with the relay switched on. Then power passes through a 40A STRTR fuse in the underhood fuse block to a purple wire that goes to the starter. So your diag should be this: You said you have power at the relay in only one of the four terminals, correct? You should have power with the key on at pin 30 all the time (These numbers 30, 85, 87, 86, are marked on the relay. Look at it and that'll tell you which terminals to check) You should have power at terminal 86 when you turn the key on. If you don't, you aren't getting a start signal from the PCM. From there you'll have to check at the PCM for 12V on the yellow/black wire. If you have 12V there but not at the relay there is a broken wire between the PCM and fuse block. IF you don't have 12V at the PCM, check for 12V at the ignition switch on the pink wire w/ key in start position, if you have 12V there, check at the BCM for 12V. That should be a good start, I can give more info from there if you need it.

loosegoose Beatrice aint that far from me. whats the name of your shop for next time I got trouble?

I work for a police department so you might have a hard time getting your vehicle in But I can on occasion be convinced to do a side job here and there, but I'm limited since the shop provides all tools. I still have most of my tools from my dealership/private shop days, but sold all the bigger stuff.

trapper4 one other thought: is your security light on or flashing with the key in the start position? If so it's off to the dealer because it'll require a scan tool to diag and fix.

Thanks a bunch guys, I am heading out to check all the information. I will check back in soon.

[quote=danny clifton]I don't have a clue why ignitions have to be so complicated. clutch safety switch, neutral safety switch, anti theft proper key cut off, low voltage relay, and who knows


So the ordinary guy can't work on it

That's what happens when you bring lawyers into the engineering office.

New vehicles are more complicated because of the equipment in them. Using the example of the ignition switch, in the old days, the ignition switch would power up your ignition coil and everything else that had key on power. maybe 30a worth of stuff. Now these days, when you want to use your remote start to shut off your alarm and anti-theft system, start your vehicle from the comfort of your living room, and crank up your eight speaker stereo system, with the heated seats, mirrors, and rearview defroster going, that just isn't going to happen through a regular switch, not without running some massive 8 gauge wires to an ignition switch, It's much easier for the manufacturers to have a ignition switch control a small amount of current and use modules to communicate and control various functions. Networking is another big difference between old and new vehicles. Networking is how different modules can communicate information with eachother. Think of your vehicle speed sensor-the pcm uses it for all kinds of things. The ABS module uses it. The radio uses it for automatic volume adjustment. The body control module might use it to control an electronic parking brake. If there was no network, the speed sensor would have to run to each one of those modules individually. With networking, the PCM receives the signal, and can share it with all the other modules on the network. New vehicles really are better than old vehicles in most every way. They're faster, more fuel efficient, stop better, handle better, are more comfortable, last longer, and have way more creature comforts than cars from "the good old days". The only way old cars beat new cars is in style and class.

My thought. Security lock out or fuse in the side dash.

Engine is locked out- lock with car symbol. Any ides on how to disengage the lock out?

All true. But you could get enough tools and diagnostic equipment in an awol bag to fix anything that was wrong with a vehicle made in 1980

New ones break down too and when they do it takes a tow truck and a dealer lots of times.

100,000 miles a car bought today is just broke in good. in 1980 it was time to shop for another or spend a lot of money on the wore out one. I think the pluses and minuses kinda balance each other out

Just thought I would let you all know what the problems were.

Bad wire from body control module and bad fuse box. What a fight, but she purrs like a kitten now.

Thanks for all the help guys.