|
|
#1
01-01-2010, 04:26 PM
|
|||
|
|||
Glowplug system
Ok, How does the glow plug system function? More specificaly, what drives the glow plug light on the instrument cluster?
I just replaced 3 glow plugs to get my car started, I KNOW the other 3 need to be replaced but wanted to get the car to start first. Something I noticed when I got the car was the glow plug light in the instrument cluster never came on. Today with the entire glowplug bus unplugged from the relay the light would briefly come on for like 2 seconds then go back out. WHAT makes this light go on or off? I would guess the glow plug relay, but how??
__________________
2000 Dodge Ram 5.9l Cummins, 5spd, Dually 4wd 1983 Volvo 244 gl, D24, 3spd auto, sedan 
|
|
#2
01-01-2010, 06:45 PM
|
|||
|
|||
|
On a 240 Diesel, it's rather complicated, or at least it can be depending on the year. On early cars, like the '82 I used to have, there are at least two units involved, one called a "blocking relay" under the dash that does most of the controlling, and then the actual glow plug relay which routes current to the plugs and is, IIRC, actuated by the blocking relay. I believe the blocking relay is responsible for turning the light on and off. On later cars, '84 and up, it uses one large relay/controller that is shaped like a brick and is the same one that is used on the 700 TD cars, which takes input from coolant temp sensor, ignition, and starter and then sends output to plugs and to light. The illumination of the light is *not* directly correlated to the operation of the plugs in this system, and I believe that may be the case in the earlier system as well.
On a 1983, I don't know what you are going to have. What does your GP relay look like? Is it a somewhat rounded-cornered one with only 4 terminals (2 big threaded posts and 2 spades), or a bricklike one with 2 big threaded posts and then a multi-pin harness connector? Regardless, I believe the light should come on when you turn on the key, no matter how many glow plugs are dead. If that is not happening you may have issues with your relay, cluster, or wiring. However, as long as the plugs work and the engine starts.....
__________________
86 745 D24T/ZF 345k lifted 2.5" 83 764 D24T/M46 155k
|
|
#3
01-02-2010, 05:40 AM
|
|||
|
|||
|
Tongue in cheek, there is always the diy alternative. A ford starter relay with a push button on the dash. A bit simplistic but it works and if you can count to 10 its just fine.
My car came that way. PO rigged it. Most of the time I count to 6 before cranking. In colder weather longer. I live close to the tropics so I never see very cold weather. Its more important to have 6 working Bosch glow plugs and a properly functioning cold start device. How you power them and for how long seems to be secondary. They will glow red in about 3 secs in air. Steve
|
 |
|
|
Linear Mode
