Electrical Problem - Can't start

[CyberHippie]

Hi Folks,

I'm a new Skoolie owner and I love my bus! I wanted to start it up once before settling down for winter, but can't seem to get it going. I drove it once to get it to it's current location, and I had it started one time after that. The most recent time I went to start it, I wasn't getting any power at all. I took the battery home, turns out it still had a full charge. Took the battery back up, tried wiggling lots of wires etc. I noticed a battery kill switch, so tried that in both positions. No luck at all, no lights or anything.

I can't think of anything I could have done that would cause a change, when it was working fine before. Could it be some sort of safety device, that keeps it from starting if X condition is in place? I really have no idea... I'm not very knowledgeable when it comes to vehicles but I'm learning. If anyone could point me to a few things I could check on or try I would really appreciate it. I suspect the fuse box would be a good place to start, however I have no idea where it is at the moment.

I don't have any documentation on the bus so all I really know is that it is a 1982 GMC Bluebird, with a 427 gas engine. There are some model numbers etc on some metal plates still attached inside the bus, which I can note next time I go there, if it would be helpful.

btw - awesome resource here, it's nice to know I'm not the only crazy person who wants a bus for a cottage! I know this site is going to be super helpful as I mod and upgrade my skoolie!

Thanks

 

[the_experience03]

Are you not getting any power at any time under any conditions or is the bus simply not cranking? A quick and easy test to see if the battery has the ability to feed the system (i.e. complete circuit) would be to have someone push the brakes and see if the lights come on. This circuit is hot all the time no matter what as long as you don't have air brakes and depleted tanks. Your headlights should also work.

Personally, I ALWAYS start by first measuring battery voltage (12.6 volts open circuit) and then the grounds. If you have no power at all it almost has to be a ground issue. For all those circuits running everything you will likely have only one or two mega grounds. Since electricity needs a complete path your grounds are every bit as important as the feed side power wires and are usually the most exposed to corrosion while being the least maintained.

 

[CyberHippie]

No power at all. No headlights or anything. I haven't tried the brakelights, good tip, sounds like that probably wouldn't work either though. The battery has a full charge.

The former owner mentioned that once he had a similar issue and just moved the wires around and the headlights eventually came on. It sounds like your diagnosis of the grounds could have something to do with it. So what should be my course of action? Locate the grounds, and clean the contacts? What should I look for to locate the ground points? Could it have anything to do with the battery kill switch?

Thanks a lot for your help!

 

[timbuk]

id check 2 things first 1,check the ground cable where it grounds out on the block.undo it, clean it up and put it back.2,check the wire that goes to the solenoid,should be on the starter,next to the big cable heck check them all down there. thats a good start hope that helps

 

[CAMO-MONSTER]

AND CHECK THE FUSEABLE LINKS THAY MITE LOOK OK BUT FEEL FROM THE END OF THE WIRE TO THE MOLDED PLASTIC IT SHOULD ABOUT 8" IF YOU CAN'T FEEL NOTHING OUT OF THE ORDINARY TRY LIGHTLY AND WATCH IT TO SEE IF THE INSULATION MOVES OR GETS THINNER. THESE WILL BE AT THE BATTERY OR THE STARTER

 

[lapeer20m]

here are a few things to help diagnose the problem.

use a volt meter or a test light. first make sure the test light works when you touch it to the positive and negative poles of the battery. Next, touch one end to the positive terminal on the battery, and ground the other end to a shiny piece of metal on the bus. If the test light comes on then the battery is in fact grounded to the chassis. If the test light does not come on, then you certainly have a ground problem.

if no ground, you can get a large 00 battery cable and attach it from the negative side of the battery directly to the chassis. This might fix the problem.

If you have a ground, then the problem is most likely with the positive wire. Crawl under the bus and follow the positive wire from the battery to where it ends, most likely in the engine compartment or electrical panel. If the wire physically looks ok, and the connectors at the end appear ok you can move onto the next step.

At this point, you should check voltage between the positive wire termina l( that's either in the engine compt or electrical panel) and ground. This will tell you if power is traveling from the battery to this point. If you have 12 volts (or your test light works) then i'd start thinking about a bad solenoid.

most buses have one or more master soleniods that look like a ford starter solenoid. These devices supply almost all of the bus systems with current when the key or master power switch is turned on. oh that reminds me......you should check the voltage on both (all) terminals from the master power switch when the switch is on. If you have a large wire connected to a terminal on the switch that does not have 12 volts then this switch is your problem. you can buy a new switch, or bypass it all together and connect the two large wires to the same terminal. A soleniod is really just a big switch. Same approach applies to these devices. There are two large terminals. one should be hot all the time, and the other supplies current only when the solenoid is activated. If you can' get power to both sides of the solenoid, there are two possible problems. There are two small wires that go to the solenoid. One is ground, the other gets a small amount of 12 volt current when the key is on. You could run a temporary 12 volt wire directly from the battery to the proper small wire on the solenoid to see if it'll work.

anther option is to use a set of jumper cables and run the red one directly from the battery to the large terminal on the master solenoid that does not have power. if the bus systems like headlights etc seem to come to life, then there is a problem between the solenoid and the battery.

where do you live? maybe i'll just stop by lol

 

[talk2cfs]

Ive got a 89 Ford 370 gas engine bus. Been sriving it and have had no problems drove it a a week ago and parked it for 10 days, went to start it and had power but not turn over. Checked the batteries and both are good. Tried to by pass main silinoid and no luck. I put a new silinoid and starter on and still no turn over. What is interesting is that the power side of the silinoid shows 12+ volts but when key is turned on it drops to 8 or less. I think I checked all the wires and grounds and all look good. Dont understand why the volts drop wjen the key is turned on. There is another silinoid looking thing in the bus behind all the switched that clicks evertime I turn the key on and also my volt meter in the bus only shows about 8 volts when I turn on key. Any ideas would be great. thanks alot. Jeb

 

[Elliot Naess]

Sounds like your battery, Jeb. The voltage will drop when you complete the circuit and allow the electrons to flow. The question is how much the "pressure" drops. In auto mechanics school 40 years ago, I was taught that 9.6 volts was the lowest that would work. I cannot say if the battery is just discharged or on its last legs, but that's where I would start looking. Sorry the news isn't better.

 

[talk2cfs]

Ok. Not the battery, starter, or silanoid. Replaced all that. Now what is happening is the key wont controll anything. When I hooked up a jumper cable to the ground of the battery and the frame, I got power and the engine turned over. then I couldn't get the key to shut off so needed to unhook the jumper cable just to stop the starter. So, I took the igintion switch off and had it looked at and it seems to be fine, reinstalled it and still not power from key. Sounds to me that it is a ground problem, but why is the ignition still stuck on? I did find a 12v wire that was going to a back up camera to the back of the bus that was shorted out and removed that from the power source (battery). I think that might have been the original problem, but now no power from key or ignition. What do you think could be wrong now? Thanks.

 

[lapeer20m]

i totally agree that it's most likely a ground issue. Almost all wierd seemingly unexplainable problems turn out to be a bad ground somewhere.

start by re-grounding the battery to the chassis, and the engine to the chassis.

 

[bbbrt76]

well the bad ground from the battery to the vehicle chassis is bad and is the reason it wouldn't turn over fix that first even if you have to disconnect the wiring at the starter, as far as the starter not turning off, i have seen remanufactured starters do that on several occasions due to bad rebuilds (you said you replaced the starter so....) of course getting the wiring attached to the wrong posts on the starter can also cause that symptom, and finally high amperage due to poor voltage can damage starters in such a way as to cause that failure

 

[talk2cfs]

Thanks everyone that made suggestions. I figured it out yesterday in the cold and snow. I knew that I had a ground problem and fixed that, but what was confusing was that I couldnt get the starter to stop engaging when I hooked up the battery. So , I replaced the ignition switch and that didnt help. I got thinking that it is acting like the silanoid was some how being by passed. So I took off the Brand new silanoid and put the old one back on and all worked great. I believe that the original problem was the short in the back up camera wire and then the defected silanoid. Thanks again for all the help. Jeb