GP Card Question

[Milton]

Hello All,
I have bypassed the resistor in my truck and was checking voltage at the plugs. When the key is first turned, the plugs get 12v but after I hear the relay kick off I still saw 1v at the plug. Is this normal or is something else wrong"

 

[doghead]

Are you having a problem, or just checking things out?(why were you measuring the voltage)

Since a relay does not adjust the voltage, I bet you were getting a "ghost reading" with your digital meter.

 

[Milton]

I just replaced a complete set of dead glowplugs and want to make sure it does not happen again. I have taken the resistor out of the system and wanted to make sure that everything else was working properly. The plugs get 1volt until I shut of the key. Is that a ghost measurement?
Thank you for your help.

 

[doghead]

Where exactly are you measuring the 1 volt?

If it's at the glow plug terminal, have you also measured at the output side of the relay and also the input side? Do you have that 1 volt measurement at all three places?

Is it the same with the engine hot and cold?


Have you measured the voltage on the small terminals of the relay(with key on and with key off?

Have you measured ohms to ground on the blue wire on the relay? key on and key off?

 

[rnd-motorsports]

there should not be any power to the glow plugs after the relay shuts off and bypassing the resistor will not make any dif. if you still have power to GP after relay shuts off first I would unhook the glow plug feed from the relay should be orange wires at bottom of relay if stock then check to see if you have the 1 volt at that point on the empty post of the relay if yes replace relay if not check the GP feed wires one at a time the large orange ones may have a alt wire have gotten hot and started to melt find short and fix. If left this way yes will shorten life of plugs good luck let us know what you find!

 

[Milton]

I haven't had much time to measure anything else yet. I can tell you that when trying to start the wait to start light stays on for a really long time, like 20 seconds before I give up and turn it over. It cranks for a bit but does not fire. When I stop cranking for about 30 sec and then try again the engine fires. I am not hearing the regular clicks and pops I used to before I bypassed the resistor. Any Ideas on what I'm doing wrong?
If I can I will check the all the wires doghead mentioned tomorrow night and let you guys know what I find. Thanks

 

[doghead]

So, your GP system worked correctly just prior the supply voltage conversion?

What exactly did you do, to resupply the GP relay, with 12 volts?

 

[Milton]

As far a I know, it functioned well. The set of gp's died, so I checked the resistor after the fact and got 6ohms. I took out the resistor and moved the wire from it up to the block just above the relay. That is all I have done.