24v '80 BJ40, installed a remote battery disconnect and now the glow plugs won't light

[BiodieselBri]

I've got a phantom draw on my BJ40 so I thought I'd install one of those remote battery disconnects. The disconnect works - when it is off I can't crank the engine and no power works. When it is on, I can crank the engine and I get other power - except the glow plugs. Any idea what's going on?

 

[charliemeyer007]

I'm not a diesel expert. Does your disconnect work on the negative terminal?
Easy test take the disconnect out of the loop - do your glow plugs work? Yes - something in your installation causes the problem. No - well check the fuse maybe you shorted something out and blew the fuse. Maybe the glow system is dead or has a broken wire or something.

 

[45Dougal]

How do you activate your glow plugs?
Key turn backwards via the controller or simple aftermarket Wilson switch?

If you use the key, does the relay go clunk?
Do you have no glow power AFTER starting as well as during starting? (the controller should energize the plugs for a short time after starting).

Phantom drain is often alternator / regulator - check its charging properly... your plugs could have been rewired strangely - what voltage plugs do you have fitted?

Share a couple of photos of your setup.. maybe helps

 

[BiodieselBri]

If I remove the remote battery disconnect from the system, everything works as normal, so nothing is broken.
With the battery disconnect installed, the glow plug relay does not go 'clunk' but all other power works and I can crank the engine.

EDIC fried a long time ago, so there's no electric start.

To activate the glow plugs I turn the key to 'on' so there's power to the system and then I hold down one of those manual switches, (I upgraded the original B engine to a 3B). When it works I can clearly hear the relay clicking on.

The battery disconnect says it's rated for 230amps, is it possible that the glow plugs exceed that?

 

[charliemeyer007]

Well I think the starter might pull way more amps than 250.

Seems to me there is something in the remote disconnect system causing the problem. There are manual disconnects for batteries might be a better option. Open the hood, flick the switch to connect or disconnect the batteries, close the hood. Or you could find the battery drain and fix that issue.

 

[BiodieselBri]

The starter cranks fine though, that's the funny thing.

I'm trying not to have to open/close the hood unless I have to, and in my area there is a lot of car theft, so having the battery disconnect at least gives a small extra bit of protection. So kind of two birds one stone thing.

 

[charliemeyer007]

I have room for two big batteries. I was going to build a cable operated "knife blade rocker" switch for the negative terminals. That I could select which or both batteries were connected. You could do the same but have both or none connected. No opening the hood, just pull/push the cable knob.

You could also figure out why your remote thing isn't energizing the glow plugs.

 

[45Dougal]

Ok I see. So you don't turn the key backwards as it was originally.
My guess then is that you have some resistance built up on either the ignition switch, or the push button switch and its only just enough to trigger the glow relay.

By adding the battery isolator, you probably added some small resistance, and it has just about tipped it over the edge. The trigger inside the relay box is probably electronic. That means it needs a certain voltage to actuate, and maybe that it a bit too low now.

Quick test - hook up a battery charger so you have 13+V at the battery and see if that changes anything.

Next check the Wilson switch wiring, and clean the switch out. Jiggle the ignition switch with some wd40 etc