Community Forums

peterdube · 06-12-2022, 06:21 PM

Hello, looking for help as to why it does not go out. I understand the reason for it but why is it staying on? Just a pain seeing it on. Thanks in advance. Peter in Maine.

8.3Oilbuner · 06-12-2022, 06:45 PM

Hi Peter from Wa. state. Not sure exactly how the wait to start system works, but have a guess. I am sure it is a timed module or relay. Sounds like it might be stuck in the on position. Just curious, does the intake heater for the engine cycle as it should when the engine is cold? I don't think the wait to start light is directly connected to the grid heater. That is another system. By any chance have you tried using the chassis battery disconnect to turn the chassis power off for a couple of minutes and see if the system reboots? Not sure that would work but it is an easy try. Only thing I can think of at this moment. I am sure others here know that part of the system better than I. I have had 2 Windsor's and not experienced the problem you are having. Hope you get it fixed soon.

jacwjames · 06-12-2022, 07:42 PM

I checked my chassis wiring diagram and the "Wait to Start" light is controlled by the ECM and from what I can see no other part of the wiring.

I did a quick search of my maintenance manual that I had downloaded from the Cummins Quickserve site and could not find any trouble shooting points.

So I'll be watching this thread and see if anyone else can help.

nvs4602 · 06-12-2022, 08:29 PM

The wait to start for most diesel is for the glow plugs to heat up so the engine will ignite the fuel on cold starts. So you might need new glow plugs.

153stars · 06-13-2022, 01:24 AM

I think there's grid heater solenoids or relays , I wonder if ECM not seeing them cycle or an issue with, Intake Air Temperature sensor. Does wait to start even come on over 70f. I dont think my M11 has heaters or other over 11 Liter motors
Here's a post discussing some issues. Along with grid heater temp sensor which I have no clue about.
https://www.monacoers.org/topic/4006...-heater-relay/

jacwjames · 06-13-2022, 06:14 AM

Quote:

Originally Posted by 153stars

I think there's grid heater solenoids or relays , I wonder if ECM not seeing them cycle or an issue with, Intake Air Temperature sensor. Does wait to start even come on over 70f. I dont think my M11 has heaters or other over 11 Liter motors
Here's a post discussing some issues. Along with grid heater temp sensor which I have no clue about.
https://www.monacoers.org/topic/4006...-heater-relay/

My wait to start light comes on in any temps. But it could be a timed delay to allow the ECM to "evaluate" the conditions before going out.

153stars · 06-13-2022, 08:08 PM

I read that in the thread I shared .....that you were involved in lol
I know DEF models do an evaluation as well for DEF type stuff a "wait to start" on big motors without heaters.
I'm leaning toward one of those manifold or grid temp sensors.

Quote:

Originally Posted by jacwjames

My wait to start light comes on in any temps. But it could be a timed delay to allow the ECM to "evaluate" the conditions before going out.

Jon_C · 06-13-2022, 11:12 PM

My wait light comes on for a couple seconds even in hot weather, i have a voltage readout on my scan gauge and i can tell if the grid heater is on due to the voltage drop, i wonder if his heater is actually staying on or not. My guess is bad temp sensor, im assuming it uses the intake air sensor.

peterdube · 06-14-2022, 12:22 PM

Thanks guys for all the input. I'll be going outside too see what I can get into in a few minutes. Wish me luck. Once again,the grid heat as it should only the "wait to start" lite won't turn off. Peter in Maine.

96 Wideglide · 06-14-2022, 12:35 PM

Quote:

Originally Posted by peterdube

Thanks guys for all the input. I'll be going outside too see what I can get into in a few minutes. Wish me luck. Once again,the grid heat as it should only the "wait to start" lite won't turn off. Peter in Maine.

Well, if your grid heater 'is' staying on as the lamp suggests, it's drawing a lot of battery power, and wearing itself out!

Skip426 · 06-14-2022, 12:36 PM

Quote:

Originally Posted by peterdube

Thanks guys for all the input. I'll be going outside too see what I can get into in a few minutes. Wish me luck. Once again,the grid heat as it should only the "wait to start" lite won't turn off. Peter in Maine.

Wait to start light; as Jim mentioned ; is a function of the ECM , if the grid heaters are working and the light says on , then it's possible you have an " intake air temp sensor " gone bad .
I'd have to check Cummins ISC info , but this particular sensor if faulty , might set a code in the ECM but NOT turn on the CEL .

Have you scanned the ECM for fault codes ?

bjohnsonmn · 06-15-2022, 07:49 AM

Do you have a way to read codes from your rig? I believe there is a way to "read" codes using the dash lights and the engine diagnostic/increase/decrease switches on the dash. I once saw a guide on how to do this. I have a BlueFire that gives me access to the ECM telematics in real time.

peterdube · 06-16-2022, 04:40 PM

Hi ,Well I read the Cummins owners manual and all that lite does is has the driver wait so that the heating grid has a chance to warm up things before starting engine in temps below 40 degrees. I can tell when my grid is cycling by watching my volt meter. Sooooo to make things simple on myself I removed the idiot lite and life is good. According to the manual not all makes comes with this" wait to start" feature ,so that tells made me more comfortable. Thanks for all the feedback. Peter in Maine

jimc99999 · 06-21-2022, 08:13 PM

At least on my 97 Windsor, the "wait to start" light comes on when the intake heating grid is on, and it takes longer in cold weather than hot weather, so I assume there's a sensor somewhere. When my batteries were a little low, like "barely start the coach" low, the "wait to start" light sometimes would stay on until I started the coach. The intake air heater just makes it easier to start in cold weather.