Wait to start

[JOG man]

Looking for advise.my wait to start lite will not go out after engine fires up regardless of warm up time. It was intermittent but now seems to stay on while driving. It is an amber lamp so is suppose it is not a danger to the system. However I would like to resolve or remove this lamp. We only travel warm climates in a 2000 American eagle with 22,000 easy miles

[Skip426]

Wait to start light is controlled by the Engine Control Module, and is turned on according to info supplied to the ECM by the intake air temp sensor.
JMHO. 99% sure you need the intake air temp sensor replaced.
A scan of the sensor reading would confirm this.

[Hooligan]

Wait to start normally goes out when intake heater has brought the temperature to safe level for start. May be sensor problem, but check your volt meter. On the initial starting it should show a load (voltage drop) from the intake heater. Voltage should rise when heater drops out and temp is good to start. Concern would be the intake heater not dropping out..

[JOG man]

Thanks for the input.whats your take on continuing on with this issue? We are in route to KY right now and la has been on science leaving mid FL this morning. I will have it looked at when we get back.

[RustyJC]

Most Cummins will have a relay that is energized by the ECM to turn on the grid heaters. Be sure your relay is not sticking in the "on" position, although this should be fairly apparent from the dashboard voltmeter as the chassis batteries will show to be lower than normal. Because of the high amperage draw of these heaters, the relay contacts might be welded together.



Rusty

[JOG man]

Once again is there any worries driving with this condition? Although we have been going for seven hours today with no apparent problems.
Can any off you point me as to where to find this relay and what it may look like?
Thanks for the help
Jim

[Skip426]

Intake heater is attached to the top of the intake manifold, about 2 1/2" thick under the charge air supply tube. There shoud be 2 heavy wires running from one side of the heater to the relays,the wiring on the other side is to ground, on Dodge P/Us the relays are within a foot of the heater. If the heaters are stuck on , there is a danger of over loading the alternator, they draw a lot of power. I'm sure if they were on for 7 hrs you would have a low volts condition by now.

[JOG man]

We have pulled into a park for the evening in south GA. And after your post I took a look at the battery charging volts and it is a bit higher than usual after running all day.
I am going to have a look at the intake system in the morning to see if I can disarm this system. The batteries will charge overnight plugged into post but I will deal with this issue whether or not. This is a 350 Cumins on a 2000 Eagle. Any more in put will be appreciated.
Thanks Jim

[Chaffeekid]

Jim, just my two pennies, if the heater is actually on it will heat the intake air and reduce the MPG. And if the heater is on all the time, not good for it I would presume.
Again just my opinion, and of course we all have them.
Happy Trails
Jim

[jauguston]

Take your digital multimeter(If you don't have one you should. Radio Shack or Harbor Freight has inexpensive ones that are fine) - set it on DC volts and probe the two heavy terminals that power the grid heater. Its on the intake manifold between it and the air tube from the CAC. It should read battery voltage when it is on and read 0 Volts when its off.

[JOG man]

[QUOTE="jauguston;1529997"]Take your digital multimeter(If you don't have one you should. Radio Shack or Harbor Freight has inexpensive ones that are fine) - set it on DC volts and probe the two heavy terminals that power the grid heater. Its on the intake manifold between it and the air tube from the CAC. It should read battery voltage when it is on and read 0 Volts when its off.[/QUOTE

I do have a multimeter. Could you explain what CAC is? Forgive my lack of knowledge on acronyms. And if it is found that this voltage is reading which I think it may be I would just like to eliminate the preheat all together since I was told not to wait for that lamp to go out before starting in normal climates. Male sense to you?
Thanks for you concern in trying to help .
Jim

[Dr4Film]

CAC = Charge Air Cooler

http://en.wikipedia.org/wiki/Interco...rge_air_cooler

Dr4Film ----- Richard

[Old Scout]

Lots of good input here--to know exactly what is going on, you will need to check for voltage, either at the grid contacts on the engine [harder to identify and test] or at the heater grid solenoid [usually located in the engine or battery compartments]. Watching the voltage gauge on the dash, you should see the voltage drop fairly dramatically when you turn the key from off to the "on" position [not start position]. "Normally," the grid heaters will engage for about 10 secs, then drop out. You should see the voltage on the dash gauge recover once the grids drop off line [again, before engaging engine starter]. Once the engine is running and the alternator is at full output, I doubt if you would see the impact of the grid heaters going in/out on the volt gauge.

[jauguston]

CAC=Charge Air Cooler also known as Intercooler. It is a radiator type device placed in the engines incoming combustion air stream down stream of the turbocharger. Its normally right in front of the radiator. The turbocharger puts heat into the combustion air reducing its density. The CAC cools the air back down to increase its density before it flows into the engine. The electric grid heater is in the air flow to the engine and heats the inlet air for easier cold starting. Disconnecting one of the wires on the preheater will cause no harm but "MAY" cause your engine to be slower starting depending on the current outside air temperature. If you have the preheater disconnected until you can have it repaired and your engine does not want to start a squirt of starting fluid in the air intake on the side of your coach will get it going. DO NOT use starting fluid if the preheater is operational.