Blowing glow plug fuse

[E4M]

Hi. My Avensis D-4D has been a pain to start in cold weather since I bought it last October but now it seems to be getting worse. I was recently told that the glow plug fuse was blown so this morning I changed it then tried to start the car. No improvement so I looked at the new fuse. Blown so I obviously have a short somewhere. Any suggestions as to where I should look. I don't have a sata. 

Thanks 

[yossarian247]

Hi

The first thing to check would be the glowplugs themselves. One (or more) may have failed and shorted internally. If you've got a multimeter it should be possible to check the resistance of each plug without removing them.

[DerekHa]

34 minutes ago, E4M said:

Hi. My Avensis D-4D has been a pain to start in cold weather since I bought it last October but now it seems to be getting worse. I was recently told that the glow plug fuse was blown so this morning I changed it then tried to start the car. No improvement so I looked at the new fuse. Blown so I obviously have a short somewhere. Any suggestions as to where I should look. I don't have a sata. 

Thanks 

Hi Elaine,

Agree with Nicks post and using a multimeter if you have or can get hold of one.

An alternative approach would be to disconnect all the glow plugs. Then check to see if the fuse still blows when you turn the ignition on, this will prove/disprove that the wiring is good or at fault. If the fuse holds, turn off the ignition and reconnect each of the glow plugs in turn, turning the ignition on and off. Do this for each of the glow plugs until you find that one of them has caused the fuse to blow. You can identify which glow plug is at fault that way and also rule out a wiring fault being the cause without having a meter to hand.

Fairly sure you should be able to leave the faulty plug(s) disconnected until you can get it replaced and you'll find starting a much easier process with only 3 glow plugs working. Best not to leave a repair to long though.

Hope you get it shorted soon.

[Corollanutter]

16 minutes ago, DerekHa said:

Hope you get it shorted soon.

Not sure if that was deliberate - but it's a good one!! 🙂

[E4M]

Thanks guys. All the plugs were replaced in the summer and the ones that came out looked new too so I think this has been an ongoing problem. I'm at my mums for the holidays and have only a very few tools with me so I think a thorough inspection of the plug lines and if that doesn't reveal the problem I'll be calling an electrician. It will probably work out cheaper than buying more kit and half a dozen fuses. 

Thanks again all and DerekHa, I like the opps 😄

[2009joe]

On 12/25/2022 at 9:55 AM, E4M said:

Thanks guys. All the plugs were replaced in the summer and the ones that came out looked new too so I think this has been an ongoing problem. I'm at my mums for the holidays and have only a very few tools with me so I think a thorough inspection of the plug lines and if that doesn't reveal the problem I'll be calling an electrician. It will probably work out cheaper than buying more kit and half a dozen fuses. 

Thanks again all and DerekHa, I like the opps 😄

what if you run a new wire from a 12v supply somewhere else would that fix the problem maybe through a relay switching it on from the on light from the keys on somewhere 

[E4M]

I'm not sure that I'm a good enough electrician to do that. The fuse is 80amp so there's a lot of power going through those connections. I don't want to piggyback something that's not going to work and cause more problems than I have now. I haven't looked at the schematic for the glow plug wiring yet. I'm assuming it's a stand alone circuit so I might be able to tap into something on that line to isolate the problem. A job for when the rains stop. 

[2009joe]

10 hours ago, E4M said:

I'm not sure that I'm a good enough electrician to do that. The fuse is 80amp so there's a lot of power going through those connections. I don't want to piggyback something that's not going to work and cause more problems than I have now. I haven't looked at the schematic for the glow plug wiring yet. I'm assuming it's a stand alone circuit so I might be able to tap into something on that line to isolate the problem. A job for when the rains stop. 

That's why I'm talking about a relay they can send the power and the wires coming from lights on key wire are just a switch for the relay. But problem is how 2 design it in a way that the relay comes on just for 5/6 seconds to warm glow plugs the right amount of time so not on all the time. I remember my last car that's the way I checked my glow plugs was to cross plug with Battery 2 see if heated up. I'm only thinking ways of bypassing the area causing problems. If got a direct supply from the Battery put in a 80amp inline fuse and if can find a way that the relay only comes on for 5 r 6 seconds 

[E4M]

Hi all. Finally sorted this out. The problem was a broken glow plug that was touching the block so every time I turned the key, it shorted and blew the fuse. Quick fix was to take the broken plug offline and bypass it so that the other three worked perfectly well. Final solution, change the broken plug. 

Thanks to all who offered advice and suggestions. 

 

[avetoy]

Thank you for the update!

[yossarian247]

Excelllent! Thank you also for coming back and reporting the cause. It may well help someone in future with the same problem.