wait light coming on

[choll]

My wait light is coming on while driving down the street, not all the time just everyonce in a while. Any ideas

 

[1986Blazerk5]

It might the glow plug relay, or the glow plug card. I had this happen but it never happened when starting just after driving and i replaced the glow plug relay and the problem is solved.

 

[2deuce]

I don't see how the relay could cause the wait light to come on if it is working and sending power to the glow plugs at start up. If the glow plug card is bad that would do it or the temp sensor telling the card the engine is still too cold.

 

[1986Blazerk5]

I don't see how the relay could cause the wait light to come on if it is working and sending power to the glow plugs at start up. If the glow plug card is bad that would do it or the temp sensor telling the card the engine is still too cold.

I don't know how either just this happened to me and i changed the relay and problem solved.

 

[antennaclimber]

The glow plug controller provides a ground to the Wait light to turn it on. The positive side to the light is switched with the key. If the Wait light wire between the GP controller and the light is grounded anywhere, it will turn the light on. I would trace and check the wire between the GP controller and the Wait light to see if it has been damaged or pinched and is connecting (shorting) to ground. Driving over rough terrain may help to diagnose this condition.

Additionally, if you hear the GP relay clicking when the Wait light comes, then I would say that you have a defective GP controller.

The GP relay control and the Wait light control are two separate circuits out of the GP controller.
Karl

 

[choll]

The light does not come on when the key is turned on to start I figured it was just a burnt out buld. I have the push button installed forthe glow plugs so they only work when the button is pushed. The light just started coming on a couple of days ago.

 

[1stSarge]

18. "WAIT” LIGHT OPERATES UPON RESTARTING (ENGINE HOT)

Step 1. Check connections at glow plug switch on upper left rear of cylinder head and glow plug module.

If connections are not good, clean and secure all connectors.

If connections are good, perform Electrical Troubleshooting malfunction #15.

---TM 9-2320-289-20 (2-64)