Glow plug WAIT light issues

[ramcatdoc]

I recently had all 8 glow plugs replaced in my M1009, as I was unable to start at all beginning this Fall. I suspect I had experienced the cascading glow plug failure people have written about. The truck now starts up beautifully with the first crank. It's wonderful. But I have noticed several things since the install that have me puzzled:

1. The WAIT light now comes on and stays on for about 30 seconds, regardless of how warm the engine is. Even if fully warmed up. it comes on.
2. About 30-45 seconds after cranking, I hear a ratcheting noise under the dashboard, perhaps to the right of the steering column. It sounds a lot like engaging a foot pedal parking brake, and lasts about as long as that. It's predictable, brief, and new.
3. I DON'T hear the rhythmic, clicking sound people have described as the relay card cycles the glow plugs on and off. I never have.

I bought this truck with a manual glow plug switch already installed. However, I have always used the automatic one associated with the WAIT light. I haven't tried to start the truck with the manual switch since the glow plugs were replaced. I have no idea if the relay card or the temp sensor is good or bad.

I think I found the temp sensor, connected to a green wire in front of the front left glow plug. It looks easy enough to replace, but I don't know how to test it.

Any thoughts out there?

 

[doghead]

Testing of the sensor(and the rest of the GP system) is covered in the -20TM under the Troubleshooting section.

 

[timarr]

Water temp is the one behind the steering pump with green wire. The 2 your interested in are in the rear side passenger head and back top of drivers head.

 

[ramcatdoc]

Testing of the sensor(and the rest of the GP system) is covered in the -20TM under the Troubleshooting section.

I knew that advice would be coming, as it should.

However, I have been through the TM several times for this and other issues. I find it very difficult to navigate the PDFs. And the pictures are few and difficult to interpret. Actually finding items under the hood is half the battle. I would simply appeal to folks with more experience than I who might be able to see something familiar in my "symptoms" and could share some wisdom with me.

I certainly don't want to clog the site with unnecessary posts....

Respectfully,

 

[Warthog]

Have you looked at the GP Operation sticky? Great visual on how it works.

http://www.steelsoldiers.com/showthread.php?62477-GP-Module-Theory-of-Operation

 

[Warthog]

Spend some time looking at the parts manual. Shows where things are and how they are hooked up. Each system has its own picture.

when I first started my MV journey I spent hours looking at the parts manuals.

 

[doghead]

As worthog says, the parts TM is just pictures and part numbers.TM 9-2320-289-20P

As with any book, there is a TABLE OF CONTENTS.

In the table of contents, I looked in the GROUP 06 ELECTRICAL SYSTEM (chapter)

Then clicked the link that took me to 0610 - SENDING UNITS AND WARNING SWITCHES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-1

There, I see this picture which is useful to identify where each sensor is located and what sensor it is.

The next page has the part numbers.

Maybe this will help you understand how to "navigate" the TM.

 

[doghead]

In the -20tm it says, 800 ohms (minimum) at wire (engine cold). for the sensor.

It goes through the whole system.