Need some help please

[Rickie3]

Howdy all, my son has a 99 GU 2.8 patrol, he had to replace the battery, but upon installing a new battery he has put the cables on the wrong terminal, it needless to say made a hell of a mess, ive had to replace heaps of fried fuses, but the biggest issue is there is a 100amp fuse that I assume is for the glow plugs? thats what it says on the fuse box cover, well the problem is it glows and starts fine, then this 100amp fuse starts smoking and gets so hot that its melting, so my guess he has fried something like a glow relay hence the reason the power stays onto this fuse once started, any advice as to where to fix this problem would be apprecited please

[Yendor]

It's more then likely the 100 amp fuse for the alternator.

Try disconnecting the wires (1x plug and 1x 10mm nut) at the alternator and see if the problem is still there. Make sure you tape the wires up so they don't short out.

There's a good chance the diodes in the alternator have been fried.

If it is the fuse for the glow plugs try unplugging the glow plug relay.

[happygu]

Rickie,

Have any of the wires melted in the loom. The earth wires will have taken a full battery current load....

Mic

[Rickie3]

no luckily no melted wires in the loom, I unscrewed the 10mm nut on the big fuse to get him home, this 100amp fuse in question has 2 wires running to it, one side is plain white and the other side is white with a red trace

[Rickie3]

ok been doing more searching the big fuse is for the glow plug relay, ive ran some tests with a test light, when I first turn on the ignition the glow relay clicks into life and I get power to the glow plug rail, after about 15-20 seconds the relay clicks off turns the power off to the glow rail which is what its supposed to do, but when I start the engine the relay turns back on and stays on which is not right, could the relay be stuffed? or is something else kicking the relay to stay on, the alternator appears to be ok, I have pulled the glow relay apart and it does show signs of a lot of heat and has melted some of the plastic

[Yendor]

ok been doing more searching the big fuse is for the glow plug relay, ive ran some tests with a test light, when I first turn on the ignition the glow relay clicks into life and I get power to the glow plug rail, after about 15-20 seconds the relay clicks off turns the power off to the glow rail which is what its supposed to do, but when I start the engine the relay turns back on and stays on which is not right, could the relay be stuffed? or is something else kicking the relay to stay on, the alternator appears to be ok, I have pulled the glow relay apart and it does show signs of a lot of heat and has melted some of the plastic

This is correct, it's 2nd stage or after glow.

The glow plugs will turn back on once the engine has started and stay on until the engine reaches a certain temperature.

Check the connections at the busbar and glow plugs.

[Rickie3]

This is correct, it's 2nd stage or after glow.

The glow plugs will turn back on once the engine has started and stay on until the engine reaches a certain temperature.

Check the connections at the busbar and glow plugs.buz bar has all been cleaned up and I only installed new glow plugs last week, if this is a after glow, what could be causing the fuse to start melting tho? anyway of disabling this after glow? I also took the glow plug relay out of my good working GU, and still same issue so its not a relay related problem

[Yendor]

buz bar has all been cleaned up and I only installed new glow plugs last week, if this is a after glow, what could be causing the fuse to start melting tho? anyway of disabling this after glow? I also took the glow plug relay out of my good working GU, and still same issue so its not a relay related problem

A bad connection in the glow plug circuit. Were the correct type of glow plugs fitted.

It's controlled by the ECU. I guess you could disconnect the ECU side and fit a momentary switch in the dash but this is not fixing the problem.

All diesel GU patrols have an after glow circuit.

[Yendor]

Here's the info from the worksop manual.

[Rickie3]

yes correct glow plugs, the car was fine until my son put the battery in the wrong way

[Yendor]

I don't see how connecting the battery the wrong way could cause this problem. Glow plugs and relay will work with current flowing in either direction.

[Rickie3]

then maybe the damage is done to something else to cause this problem

[Yendor]

I can't see anything else from factory that's connected to the 100 amp fuse for the glow plugs. So it would need to be an aftermarket accessory.

[Ryangtd42]

sounds like u fryed the reg in the alternator get a new reg and see how it goes