Left Glow Plug Switch On Fried Something

[TrueBurner]

Thank you for your inputs on the switches, seems like that is going to be an easy fix. I am still trying to figure out why power isn't getting to the plugs though now. Took the plugs out and they look old but not fried so to say. I used a different solenoid and same problem as I mentioned above. I just don't understand why there is no voltage going to the other post of the solenoid that connects to coil which connects to glow plug harness. Shouldn't that have a charge going to it? I'm just so confused theres voltage coming from the battery and breaker in addition to the switch working correctly and voltage coming from there, what am I missing?

 

[DaveBen]

The voltage and current (Watts) comes from the battery, goes through the solenoid and goes to the glow plug. It is used in the glow plugs to heat up the combustion gasses making them easier to ignite. The switches and breakers interrupt the current flow to the glow plugs. I hope this makes it easier to understand. Electrical items on engines can be a b--ch to figure out.

 

[TrueBurner]

That's my question, why isn't it going through the solenoid and into the glow plugs? Shouldn't I be able to read the voltage on the post going to the glow plugs? It seems like I will end up replacing my glow plugs but it doesn't make sense how current isn't going through the solenoid, unless having dead glow plugs makes it so the solenoid doesn't fire.

 

[Rdnck84_03]

Do you hear the relay click when it engages? If it has power from the battery and is getting a signal from the push button it should click and power the glow plug side of the relay.

( make sure the relay is bolted down to a good clean surface that is grounded)

If it doesn't click I would look at it closely and maybe sure that you don't have your relay hooked up backwards. If all of that checks out I would think that the new relay is DOA.

James

 

[franklin2]

Yes, you should be able to push your dash switch on off on off and each time you do this the relay on the engine should make a thunking noise.

If you are still not getting voltage on that large lug when it thunks, get someone to hold the button while you check for voltage on the other incoming lug. You may find you have voltage on the incoming lug just sitting there, but it drops to zero when the relay pulls in. If this happens, you have a wiring problem up the line.

Digital meters can do this to you, so always check for voltage when the circuit is under load.

 

[TrueBurner]

Replaced glow plugs still nothing. Have tried four relays now and not one has worked. Still the same issue no power getting to the relay plug connected to the glow plug harness. Pretty stumped. What is interesting is the two silver bolts that hold the relay in place are getting a charge going to them. Even replaced the ground wire that is connected to relay and it is grounded still nothing. I may just have the worst luck in the world with getting bad relays which may be the least surprising answer

 

[TrueBurner]

I hear a click when I initially turn the keys. But no sound when I flip the switch. Yes the incoming lug from breaker connected to battery still reads 12.9 v when the switch turns on. And lug connected to switch also reads that. Another interesting thing that may help is that when I leave the switch on and just start the truck the breaker doesn't trip. Before it always tripped if the switch was left on and it was started. Not sure if that means anything

 

[franklin2]

Do you have a set of jumper cables? Take the red side of the jumper cables, clip one end of the red to the large input post on the glowplug relay, and clip the other end of the red to the battery + terminal. What happens then when you glow the plugs with that in place?

 

[IDIBRONCO]

I hear a click when I initially turn the keys. But no sound when I flip the switch.

This may be important. It sounds like your wining for the switch is bad somewhere. You can narrow it down a little bit by checking to see if you have power to the switch.

 

[TrueBurner]

Nothing happens when I connect the red jumper to large input post coming from breaker/battery on relay and other side to + battery. If I attach the red jumper to the other large post on relay that leads to glow plugs it sparks. Also not sure if this means anything but I'm not getting a high rev idle when I've started it a few times now with starter fluid.

 

[IDIBRONCO]

Nothing happens when I connect the red jumper to large input post coming from breaker/battery on relay and other side to + battery.

Which is perfectly normal.

If I attach the red jumper to the other large post on relay that leads to glow plugs it sparks.

This sounds like either you have a big power draw or a short to ground.

Also not sure if this means anything but I'm not getting a high rev idle when I've started it a few times now with starter fluid.

You're probably not getting power to the system.

 

[franklin2]

Nothing happens when I connect the red jumper to large input post coming from breaker/battery on relay and other side to + battery. If I attach the red jumper to the other large post on relay that leads to glow plugs it sparks. Also not sure if this means anything but I'm not getting a high rev idle when I've started it a few times now with starter fluid.

The sparks are most likely the glowplugs glowing and drawing power. If you clamped it on there where it sparks for 10 seconds, and then disconnected it and quickly ran around and tried to start it, it might start.

But the first test, with the battery jumped to the first post and it did nothing, like was said by the previous poster, that is correct, it will do nothing until you go inside and press the glowplug button. If you could carefully leave the jumper on there and then press the button, or better would be for you to hold the jumper in position, and get someone else to press the glowplug button for 10 seconds, and then try to start it. If the relay thunked when they pushed the button, and the engine starts, that means your factory wire or wires from the first lug on the solenoid back to the battery has a problem.

 

[IDIBRONCO]

But the first test, with the battery jumped to the first post and it did nothing, like was said by the previous poster, that is correct, it will do nothing until you go inside and press the glowplug button. I

No. It does nothing because one end is connected to the battery positive already. Jumping battery positive to battery positive will do nothing.

 

[TrueBurner]

Want to start by saying thank y'all for all your help. I finally started using my brain yesterday and got it to work. I kept going back to why are the two bolts that are connected to the plastic module housing from the relay getting a charge. So it turns out the relay wasn't grounded properly. When initially taking the old one off and putting the new one on I put the wires exactly where they were before. I thought the fourth port (I) on the relay was for the grounding wire as that's how it was hooked up before. It turns out once I switched that wire to one of the bolts that connect relay to module, it worked first try. So that means the original plastic module that controlled the auto glow plugs had some sort of ground to it and when I left the relay on it no longer functioned that way. I never would have thought it was that since I thought it was just a piece of plastic that had all the wires cut to install manual switch. Anyways it works, momentary switch is installed and I'm living stress free. Thanks again!

 

[TrueBurner]

Side note though, high idle rev still isn't working for some reason.