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valleybusman
Top Member
USA
809 Posts |
 Posted - 03/26/2018 : 11:02:27 AM
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| I have a 05 IC FE 300 with a dt466 .We installed a new engine last Summer . It was bear of a job !!! Anyway for a few weeks after we started using it the wait to start switch light went out . Figured bulb . Bus ran but ran rough .After it warmed up ran great . So today I have the bus in my shop to replace light . I changed bulb out and still won't come on . This is going to be long so bear with me . I using my power probe showed a good ground on the dash circuit panel where the bulb sits . Okay so I check the other side of the socket . It shows 11.2 volts . So I change the light again . Same thing . So I realize my power probe does not light up the positive light but shows 11.2 volts . So I think lets see what the intake heater is doing . Good ground on that a beep and negative light lights up . Touch powerside turn key on and I get 11.2 volts but no beep or positive light . I then apply 12 volts with my power probe and it blows the circuit breaker on the probe . So now I have to find out if it's a relay or wiring issue . Now I don't know about you but the wiring on these buses is hard to get to and sometimes look like a 3rd grader did it . So now I am wondering if maybe I should just design a new way to turn the light and intake heater on . The only problem is how to time it so it will turn off after so long ? Or is it better to try and sort out the wiring mess .Looks like I would have to remove the starter to get too things . Thanks |
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eddo
Advanced Member
USA
311 Posts |
Posted - 03/26/2018 : 11:22:27 AM
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Is the wait to start light supposed to work with the intake heater? Or just glow plugs, for vehicles equipped with them?
Pardon my ignorance here, I'm in the desert and don't need block/intake heaters. :/ |
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valleybusman
Top Member
USA
809 Posts |
Posted - 03/26/2018 : 11:51:39 AM
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| It doesn't have glow plugs . It turns off to let you know to start bus |
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eddo
Advanced Member
USA
311 Posts |
Posted - 03/26/2018 : 2:06:15 PM
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right, but I've not seen a "Wait to start" light ever work on a DT466- because of the lack of glow plugs. In my desert experience, I wouldn't expect it to come on in the situation you listed.
my question is: is the wait to start light connected to a intake/block heater as well? What are you expecting it to tell you to wait for?
:) |
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Tb4020
Senior Member
United States
82 Posts |
Posted - 03/26/2018 : 6:35:17 PM
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| Wait light is controlled by the ecm, how long it stays on is factored by engine temp and ambient air temp. It could be that one of the sensors is giving the ecm a false reading so it doesn't cycle the grid heater. I've had this on some cats bus sat overnight and engine coolant temp was reading 100 degrees on a 30 degree morning that false reading caused the timing and fuel rates to be off and smokey rough start. Just a thought if you have software to plug it in. |
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valleybusman
Top Member
USA
809 Posts |
Posted - 03/26/2018 : 8:46:03 PM
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| I have service will that tell me ? What am I looking for ? |
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td083
Senior Member
195 Posts |
Posted - 03/27/2018 : 02:44:28 AM
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Ok so don't know if I'm understanding , you said there IS a good ground where the bulb sits in dash , and there is 11.2 v at power so its saying you have 11.2v but the reason its not red light is its not full battery voltage likely 12v slight difference
---regardless to me the light should work fine have you double checked the tabs are contacting the dash ok -- and I guess its possible for voltage drop once the load (bulb) is in place but ?? |
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valleybusman
Top Member
USA
809 Posts |
Posted - 03/27/2018 : 07:26:35 AM
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| I use power probe for my testing . When I have a good 12 volts it will say on the screen what I have and there is a little red light in a plus sign that will light up and I will get a beep . If it's not a good voltage the screen will show the voltage but it won't beep or light up the plus sign . In other words when I use a test light I show nothing . When I check the bulb socket I get a beep and a minus sign that lights up . means I have a good ground .Again when I use a test light on the positive side of the socket I show nothing . |
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Mechan1c
Top Member
USA
853 Posts |
Posted - 03/27/2018 : 08:43:31 AM
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| Master Service Information; go to EGES2701, standard features, inlet air heater, IAH system link. Be careful with the power probe around the ECM... |
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drp53188
Senior Member
89 Posts |
Posted - 03/27/2018 : 10:09:14 AM
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| Did you hookup the power and control wire to the grid heater controler when you did the engine ???????? |
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valleybusman
Top Member
USA
809 Posts |
Posted - 03/27/2018 : 10:31:12 AM
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| Okay more info ..... I am such a klutz ....I used my test light this time . I am getting power to the heater .The heater will stay on for 5 or 6 seconds and go off like it should . The light is not working in the dash . So I used my test light again and I have power to one side of the light . The other side of the socket must be grounded by the ECM . That is dead no ground . That's what I need to fix . Sorry for bad info . |
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torque
Advanced Member
Canada
358 Posts |
Posted - 03/27/2018 : 1:13:50 PM
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I believe if the engine is warm enough, the wait to start light does not come on.
But the heater may still come on for emissions, reduce white smoke, may still cycle after the wait to start light out, again, just for emissions.
So. is it cold enough for the intake heater to be required to start?
Also, do you have software to connect to the ECM and see what it sees for temperature, and are all your temp sensors, oil, coolant, air close to the same temperature after sitting for a while or is one way off, bad? |
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valleybusman
Top Member
USA
809 Posts |
Posted - 03/27/2018 : 3:25:25 PM
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Okay another problem ....I use my test light on the positive leg of the intake heater . Turn the key on . Lights up test light . Keep on until light goes off . Start bus and it starts up no smoke or rough idle . I here a click when this happens . Then I test the light socket by doing the same thing with turning the key on . I have power on one
side of the socket . Light will not turn because what ever grounds the light socket isn't working .Then I found out all the idiot lights aren't working either . When I turn the key on I only get an ABS check and transmission . The gauges all work fine .So I need to figure out what controls all those idiot lights . ECM fuse What ???? |
Edited by - valleybusman on 03/27/2018 3:30:51 PM |
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Tb4020
Senior Member
United States
82 Posts |
Posted - 03/27/2018 : 9:06:45 PM
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| I think you're to the point where you need to do some studying on how that system works. I believe torque hit the nail on the head, if this thing is parked in the warm shop while doing all this "testing" that light may never come on! The grid heater relay can be unhooked and in the trash it won't affect if the light comes on or for how long. The light is controlled only by the ecm as we've previously said. If that relay only came on for 5-6 seconds it probably didn't turn on the light because the ecm thinks the temps are fine for starting with out waiting for the heater to warm so hence no ground for the bulb! That's why you need to plug into some software to see if the coolant temp is accurate and the ambient temp is close to actual. Coolant temp and ambient air temp are the values used by the ecm to determine if the light comes on at all and how long it stays on if it does regardless of what the grid relay does. You can't fix it if you don't understand how it works. |
Edited by - Tb4020 on 03/27/2018 9:10:00 PM |
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td083
Senior Member
195 Posts |
Posted - 03/28/2018 : 03:11:15 AM
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---So when you check with your powerprobe what is the voltage reading at the power side of bulb??
--in your 1st post you stated 11.2 was there which would be fine even though its not batt voltage (yea I use a pp all the time ) if in fact you do have 11.2 there and it wont light with a good ground you would have to have voltage drop on the power side so basically if you have 11.2 and you install the bulb and it wont light then check your voltage likely is dropping way low due to high resistance somewhere ***this would only be correct if in fact your original 11.2 reading was correct -- |
Edited by - td083 on 03/28/2018 03:12:07 AM |
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kummins
Active Member
41 Posts |
Posted - 03/28/2018 : 07:07:29 AM
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please, please toss away the power probe & test lights, they are useless for electrical diagnosis'. they're not even good enough to check voltage for led lighting, some led's require specific voltage to illuminate and the idiot test light will 'light up' leaving you to believe the bulb is bad, when it was weak/low voltage that was the cause.
get a multimeter such as this one...
https://store.snapon.com/Automotive-Digital-Multimeters-Multimeter-Digital-Advanced-Manual-Ranging-P647143.aspx
it does everything including continuity, ohms, ac/dc voltages down to milli-amps.
i have the blue point EEDM503A and been using it for over 26 years and it's still working flawlessly. it has safety fuses inside, in case you connect to wrong voltage while in a different mode.
the intake heater should have two separate battery positive leads which connect to two solenoids usually located on the firewall above the valve cover. when they are triggered by the ecm, the dash light should illuminate. there should be two coolant sensors at the pass side front of the head, one is for the idiot light, the other is for the ecm.
as weird as it is, i have seen many dt's come factory without the intake heater, yet there is the yellow 'wait to start' on the dash & it will cycle, guess they saved on ecm programming.
some dt's with the intake heater, have come with just one positive battery feed & one solenoid, others with the two by two, depends on the intake heater installed.
when i encounter dash electrical problems, i'll disconnect the main feed at the fire wall, checking all the pin connectors, re-attach and more often then not, the problem goes away.
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td083
Senior Member
195 Posts |
Posted - 03/28/2018 : 09:34:54 AM
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Not trying to start a argument here but I'm sick and tired of what I call "tool elitist" who hate on certain tools yes absolutely they CAN be used incorrectly if I had a dollar for everytime ive heard watch out dont want to burn up the ecm this or that yes I'm well aware
The fact is used correctly every mechanic may prefer a certain tool in various situations its up to him , I can take a hammer and smash out all the windows in a bus is that a reason to never use a hammer? I am well versed in electrical use both dmm , power probe at times I find it at times easier and quicker
When Used correctly <<< in tight spots no need to look gives an audible noise for power and ground can check quicker and with one hand , can power up circuits and apply ground when needed and when aware of the circuit <<< The only argument against them is when there used incorrectly
no need to throw them away just know what you are doing and you will be fine , again this is just personal preference , but I cant stand when a mechanic trys to demonize a tool because one time Billy Bob burned up a ecm . Sorry for being sarcastic but dang enough is enough . |
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valleybusman
Top Member
USA
809 Posts |
Posted - 03/28/2018 : 3:31:09 PM
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| I have the problem figured out but don't know the why . All warning lights have 12 Volts . Something supplies the grounds . ECM ? if so where do I start looking ? Anybody have any ideas :-( The only warning lights I have are for the ABS and low air warning . Thanks TDC 083 |
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earl1412
Senior Member
101 Posts |
Posted - 04/02/2018 : 12:27:28 PM
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quote:
Originally posted by valleybusman
Something supplies the grounds . ECM ? if so where do I start looking ? Anybody have any ideas :-(
Have you checked the "body ground stud" on the firewall? If I'm reading my schematic right, the system controller is grounded to this stud via wire # A11-GAB/18ga wht from 36 pin controller connector cavity #1 and wire # A11-GAH/ 14ga wht from 8 pin controller connector cavity #B.
The ground studs should be easy to find, there's a ton of white wires going to them, there is a #K11/4ga wht wire connecting to this mess from the engine block ground.
Good luck!
earl |
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valleybusman
Top Member
USA
809 Posts |
Posted - 04/03/2018 : 10:27:37 AM
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| Not sure if you know this Earl but this is FE model . No firewall . I appreciate the input !!! Can you find where the ground wires are ? I see a whole bunch over the starter and I see some wires unplugged by the starter . But none of them plug into each other ? |
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earl1412
Senior Member
101 Posts |
Posted - 04/03/2018 : 2:53:03 PM
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quote:
Originally posted by valleybusman
Not sure if you know this Earl but this is FE model . No firewall . I appreciate the input !!! Can you find where the ground wires are ? I see a whole bunch over the starter and I see some wires unplugged by the starter . But none of them plug into each other ?
I apologize for not reading the whole OP. I only have CE buses and have no information on your FE series.
The only thing that carries over is IH uses white for ground circuits, so you might want to pull the ones by the starter apart to see if there is corrosion between the wire terminals and ground causing your issue. |
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Need electrical help :-( gonna be long
