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Buddy Tennison (Buddyten)
Registered Member
Username: Buddyten
Post Number: 26
Registered: 7-2005
Posted From: 207.68.235.83
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 15, 2007 - 12:19 am: | |
Hey Experts/Busnuts:
Back on May 24, I posted about some starting problems with my Eagle. I received your replies, and some good info, the most important being suggestion(s) of making sure all the grounds and connections were clean and making good contact.
Well, I did go through most of the electrical on the bus. The cables and ends that were or had not been replaced were disconnected, cleaned with wire brush and 80 Grit sandpaper, and reconnected. I even established a new frame ground from the batteries to the frame by cutting off the old connection bolt and affixing it to another ground connection. I also sanded down where the starter ground bolts to the engine cradle frame and new bolt, as well as where the starter grounds to the engine block. All other connections were sanded bright and dielectric grease applied liberally. Boy was that a job!! I completed everything back in the engine compartment and bulkhead. I even installed a new very heavy duty "kill switch" to insure that it was adequate to supply the power needs (that switch alone was $160 bucks) but is rated for 200A as opposed to the 50A one we had. We were told by the Mack dealer that this was the switch that Waste Management uses on all their garbage trucks where they employ 4 heavy duty batteries. On the electrical panel by the driver cockpit, I did not see much rust or corrosion there. I did take my nut driver and screwdriver, and checked and/or tightened all the connections to that board. I have not had the time to disccnnect/clean/grease all those, as we will be using the bus this weekend, and did not want to start something I couldn't finish. Found only a couple connections that were the least bit loose.
I checked what you guys refer to as "skinner valves"; one for the high idle and one for the engine shutdown. Since the engine goes into high idle at the flip of the switch, and the engine shuts down when the ignition key is turned off, I am assuming that these are operating properly.
We did not have a remote starting button in the engine compartment, and since we were there, we decided to go ahead and install one for convenience. I used a heavy duty push button switch I got from the local Truck parts dealer, which has two posts. From one post, I went to the Kill switch, and the other post with a wire (10 GA) to the hot post on the starter solenoid. The engine starts very quickly with this remote switch.
Having completed all of this, I still am having problems with starting the engine from the cockpit. As I mentioned in the earlier thread, I did have a problem that when I hit the cockpit starter button, it would kill the lights, etc inside the bus. Would have to wait a few minutes, cut off and back on the kill switch, then the lights would all come back on. Now that is not occuring. The lights, etc do not even dim when I hit the switch. I installed a new starter button replacing the old original Eagle rocker switch with one of the old push button style switches, thinking I had a bad rocker switch. I stood at the back of the bus, and had my partner repeatedly push the starter button, and there is not even a clicking sound of any kind. It's like it is completely dead. Since the engine starts quickly with the new remote switch, I know I don't have a solenoid or starter problem.
On the cockpit starter switch, there are two pole connections. There are two red wires coming from a plastic wiring harness type connection, which have been spliced together to form one wire which connects to one pole on the switch. There is a yellow wire which connects to the other switch pole and runs down to that same plastic wiring harness connector. The wires from the ignition key also run into this wiring harness connector. When I turn the key on, I get power to all the dash lights, etc as I should, so I kinda feel that the wiring harness connector is ok.
My bus maintenance manual is on CD, and we leave it with our mechanic. Unfortunately, he is gone for two weeks to Detroit's computer school and it is locked up in his office. From the faded out schematics on the electrical panels, I have kinda figured out that the starter relay is on the left side bulkhead above the engine. I also deduced this cause there is a wire running from one side of this relay down to the hot post on the starter solenoid (the same post where I hooked the new remote starter switch wire). On the other post of this relay, there is a wire which goes over and connects to the post on the main bus power supply. On this relay, there is a small orange "diode" looking thing. From the posts where this thing hooks up, there are a couple of yellow small wires that run to what appear to be grounds.
Could it be that the starter relay has gone bad? How would I check this? Do you all have other suggestions of what I should check? From this relay, there are a wire/wires that run to the other side of the bulkhead to two things that have air lines that run to the high idle and engine shutdown things mounted on the top of the engine. Is this the correct set up, and should I check something on them, although they appear to be operating correctly? If the relay is bad, is this something that I can get locally (maybe from NAPA or outher parts sources) or is this a specialty item?
I REALLY NEED TO GET THIS RESOLVED, SO ANY ASSISTANCE OR SUGGESTIONS WOULD BE MOST APPRECIATED!! We will use the bus this weekend by starting it from the new remote starter switch I installed, but that will be a pain in the ..... to have to start everytime from the rear of the bus.
I look forward to all suggestions that you may have. Thanks for all your help. |
John MC9 (John_mc9)
Registered Member
Username: John_mc9
Post Number: 376
Registered: 7-2006
Posted From: 68.205.165.5
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 15, 2007 - 1:14 am: | |
"The engine starts very quickly with this remote switch.
1. I still am having problems with starting the engine from the cockpit
2. my partner repeatedly push the starter button, and there is
not even a clicking sound of any kind. It's like it is completely
dead. Since the engine starts quickly with the new remote switch,
3. I know I don't have a solenoid or starter problem
4. On the cockpit starter switch, there are two pole connections.
There are two red wires coming from a plastic wiring harness type
connection, which have been spliced together to form one wire
which connects to one pole on the switch. There is a yellow wire
which connects to the other switch pole and runs down to that
same plastic wiring harness connector.
5. When I turn the key on, I get power to all the dash lights
6. I kinda feel that the wiring harness connector is ok. "
Why leave that one splice alone? You've knocked yourself out
shooting this trouble, why quit with an assumption that it's OK?
Trace the reds to their end, one isn't doing's it's job when the
switch is connecting the reds to the yellow.
I'd disconnect the "hot" from the starter, and wire in a buzzer
in it's place. Then I could try extending that "yellow" lead to
wherever the "red" is next connected. If the buzzer sounds, I'd
know where the failure is..... A spool of wire, a buzzer, and
a couple of alligator clips, could save you some sweat. |
George M. Todd (George_mc6)
Registered Member
Username: George_mc6
Post Number: 193
Registered: 8-2006
Posted From: 76.168.69.233
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 15, 2007 - 10:13 am: | |
Morning Buddy,
John has one heck of an answer! I think he's low on the quantity of sweat savings though?
With no diagram, we're going to a battle of wits unarmed. So, lets think about what has to happen on any bus, and see if we can figure it out.
The start relay must have a wire from the front start button, which may go electrically through something to prevent the starter from engaging with the engine running, or disconnect it as soon as the engine starts. OR, this may happen on the ground side of the relay. SOMETHING, is another relay, or a fuel pressure switch. Are you sure of the connections on the start relay? It doesn't sound like the wire from the front is there, from what you describe. If the start relay has four terminals on it, two are for its coil, the other two are the "switch." The first two "need" one wire from the start button, and one wire to ground. The second two need one wire from hot, and one wire to the starter solenoid.
No dimming lights now means the starter isn't trying, and no click means the starter isn't being told to try. Work from front to back with John's buzzer, with the wire from the solenoid to the relay off, when you get to where you buzz on one terminal of the relay coil, it should click, unless there is an open ground circuit due to the above. If you get a buzz on the incoming wire, and no click, try the buzzer on the ground side. If it buzzes, the coil is good, the ground isn't, or you are interlocked out by something, or a failed component. Buzz on the in, NO buzz on the ground, no click, bad relay. Buzz on the hot from the starter post all the time, if not=problem. Click, buzz on relay output wire to solenoid=time to reconnect wire and start. Click and no buzz means bad relay. |
Chris Peters (Chris_85_rts)
Registered Member
Username: Chris_85_rts
Post Number: 27
Registered: 11-2006
Posted From: 66.194.150.45
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 15, 2007 - 10:21 am: | |
If the cockpit switch does nothing, this is easy to troubleshoot. If you don't already have one, get yourself a cheap <$10 Digital Volt Ohm Meter at Radio Shack or Harbor frieght.
To use this, set it to DC Volts. Touch the black probe to ground, and the red probe to what you are testing. Test as follows:
I am assuming you have a 12V system, if it is 24, then just substitute 24 for all my 12's.
1) When start switch is not pressed, you will need 12v on one pole, and nothing on the other.
2) Press the start switch and you should now see 12V on both poles. Is you do not see 12V on the second pole, your switch is bad. If you see 12V on one pole and something less on the other pole, the switch is weak, or not built to handle the current. If you see less than 12V on both poles, then you have a problem in the wiring feeding the switch, and you will have to trace it back to the fuse or circuit breaker feeding the switch, and it might also come from the run switch which could be bad.
3) Assuming you passed the above tests, and it still won't start, move to the start relay in the back. I am guessing this has 4 connections. Start Switch, Ground, Battery, Starter. With the start switch not pressed you shuold only have 12V on the battery connection, 0v on the rest.
Now press and hold the start switch. You should be able to clearly hear and feel the relay clicking on. You should have 12V on the start switch wire and now 12V on the starter wire.
If you hear no click, but you have 12v on the start switch wire, then check the relay ground. If the reply ground is good, the coil of the start relay is bad and needs to be replaced. You can test this by disconnecting the start switch wire and the ground, setting the meter to ohms, and touching the probes to those two terminals. If you get a low reading, say less than 100 ohms the coil is good, if you basically no reading or greater than 1 M ohms, the coil is blown.
If the coil tests good, but you still do not hear a click, the relay is mechanically defective.
If the relay clicks, but you do not get 12V on the starter wire, then the relay contacts internally are bad, replace it.
If the relay clicks and you get 12V to the starter, then move to the starter. Check there for 12V on the solenoid. If you do not have 12V or less than 12V on the solenoid, then you have a wiring problem between the relay and the solenoid. If you do have 12V and nothing is happening, then hit your remote starter, and see what voltage you get that makes it work.
Feel free to email if you need any additional help. cpeters1 at cfl dot rr dot com |
Chris Peters (Chris_85_rts)
Registered Member
Username: Chris_85_rts
Post Number: 28
Registered: 11-2006
Posted From: 66.194.150.45
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 18, 2007 - 11:12 am: | |
Any update? |
Jack Campbell (Blue_goose)
Registered Member
Username: Blue_goose
Post Number: 14
Registered: 5-2007
Posted From: 71.101.55.168
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 18, 2007 - 2:14 pm: | |
If you are starting good from the back, save lots of work and put in another solenoid in the back of the bus. Let the starter button up front work the solenoid only and use the contacts on the solenoid control the starter. That way there isn't any load on the forward switch. You have a short run to the starter just like starting from the back. I also had to do this on my brake light switch. I had so many lights that I couldn't keep a brake light switch. Now the switch has worked for over ten years. |
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