Hi all I have just installed a heater to our 14' expanda, it starts and runs fine on a lead acid 12V battery but when I connect it to the vans house battery (ritar 12V gel) it blows fuses instantly.....I'm stumped, the meter shows 12.8 on the lead acid and 12.3 on the gel. Any ideas ?Cheers
Stu
Electrical Diesel heater blowing fused
- Thread starter Waratah
- Start date
Well @Waratah , it won't be the battery in the van!! More likely a wrong/reverse connection and/or a short to earth point in van. Where are you taking the 12 volt feed from to run heater?? And don't forget that the diesel heater on "start up" can draw up to 10 amps on that circuit alone, so make sure fuse is rated for that much current and there is nothing else on that circuit at the same time.
That's my best guess too. If the LA battery is fine then I would disconnect the van battery from everything to confirm the fuse does not blow because the battery chemistry is no way a factor. I would remove the heater cover to confirm the wires are all tidy, then check every install screw (including the control display as it has 12v in it)) and then every point the loom passes through a hole
If it fires up on one battery but fuses when on house battery then something has changed, after testing on the other battery did you tidy up the wiring ? In which case I would try the first battery again and see if it pops a fuse ..... Battery chemistry wouldn't be it and if the van wiring was suss it would be popping fuses eleswhere I would think, something has to have changed.... though 12.2 on the GEL is a bit low for cranking up one of these things needs a bench charge.
I would try the first battery again, remove other circuits from the house battery and also take cover off heater to see if fan still turns freely a jammed fan could load up things.... confirm black on black, red on red ....
In process of fitting one in a van at the moment and hoping later today it will fire up without any drama, had enough just lately.
I would try the first battery again, remove other circuits from the house battery and also take cover off heater to see if fan still turns freely a jammed fan could load up things.... confirm black on black, red on red ....
In process of fitting one in a van at the moment and hoping later today it will fire up without any drama, had enough just lately.
As stated by others an active wire (positive) in the heater circuit contacting the chassis is a likely possibility. This would assume that the heater is not deliberately earthed (negative) to the chassis. It is likely that the house battery is earthed (hence why the suggestion to isolate the house from everything).
If you do not want to remove the lead from the house battery, I would suggest with the diesel heater disconnected from all batteries check the resistance between the positive lead of the heater and the chassis (or the negative of the house battery). To blow a 15 amp fuse on 12 volts the resistance is less than 1 ohm. I would expect that you should not get any resistance between positive of the heater and the chassis.
I am assuming that if you can install the heater, you may have a multi-meter and this is do able.
This should confirm that you are looking for a short to the chassis from the heater wiring.
If there are connectors, fuses etc for the heater disconnect them and do the test again for each section of the circuit. Or leave the multi-meter at the heater positive to chassis and then one by one re-connect starting with the fuse. If only one connector then check each of the pins to determine what might be shorting.
I would not rule out positive to case in the heater and negative is isolated. So the issue could be the case being connected to the chassis.
Hope this helps
If you do not want to remove the lead from the house battery, I would suggest with the diesel heater disconnected from all batteries check the resistance between the positive lead of the heater and the chassis (or the negative of the house battery). To blow a 15 amp fuse on 12 volts the resistance is less than 1 ohm. I would expect that you should not get any resistance between positive of the heater and the chassis.
I am assuming that if you can install the heater, you may have a multi-meter and this is do able.
This should confirm that you are looking for a short to the chassis from the heater wiring.
If there are connectors, fuses etc for the heater disconnect them and do the test again for each section of the circuit. Or leave the multi-meter at the heater positive to chassis and then one by one re-connect starting with the fuse. If only one connector then check each of the pins to determine what might be shorting.
I would not rule out positive to case in the heater and negative is isolated. So the issue could be the case being connected to the chassis.
Hope this helps
Thanks everyone, I (you) found it.
Took everything off the van battery and connected heater only .... running fine.
So the heater case is positive and I secured the exhaust pipe to the van chassis !
As always you guys are great!
Cheers
Stu
Took everything off the van battery and connected heater only .... running fine.
So the heater case is positive and I secured the exhaust pipe to the van chassis !
As always you guys are great!
Cheers
Stu
That is so weird while I thought if the case was live the exhaust would be shorting it out but to be actually a positive earth set up is just dumb, just check that the fans are running the right way or does it say it in the paper work that its a positive ground set up ???? but then if it fired up it must or it would have fizzled, unless a wire is loose inside the firebox ...... like the glow plug is shorting, once its up and running and the power draw drops down put the meter on the fire box and see if its still runs a circuit, if not then the glow would be arcing to the casing, since its now not earthed it won't blow a fuse....
This one I just finished, yet to fire it up, is number 5 I have fitted and have never come across a pos ground unit yet, I know that all they all have metal brackets on the exhaust so I suspect a loose wire....
I think it could be a pssible cause, just have to check it all thru the stages as its only on when firing up................. this very flash chinese knock off that I have just fitted the instructions look really great but nothing about the first firing up, priming that initial start one little bit, going to be interesting when I do, I will just bleed fel to the pump then hit start , hopefully it will all fire up properly because I am in no mood to stuff around with the thing... if it blows fuses I will certainly have a heads up on what to look for .... Fancy a shed that has all types of oil,and petrol and no diesel, son in law is a wood butcher so anything relating to steel is hard to find and the pride and joy is an EH .... I have decided no more Doc Drover house calls for vans, I need my own shed...............
Of course if it all works fine don't dig too deep just let it go, you know it so you own it, no need to get too anal with it............... I blew up 2 heaters before I had them sorted out........well I cooked the frst one the 2nd was an internal fault and not me for once....................... most important to not extend the exhaust unless you go to around a 45mm exhaust pipe, just extending the 25mm pipe will cause it to burn out by back pressure heat......... Some of these cheapies are really quite good at $300 last for years.....
Of course if it all works fine don't dig too deep just let it go, you know it so you own it, no need to get too anal with it............... I blew up 2 heaters before I had them sorted out........well I cooked the frst one the 2nd was an internal fault and not me for once....................... most important to not extend the exhaust unless you go to around a 45mm exhaust pipe, just extending the 25mm pipe will cause it to burn out by back pressure heat......... Some of these cheapies are really quite good at $300 last for years.....
Yep paid $300 for this one, it will get a workout for 2 weeks at the end of June when we head up to Darwin (from Melbourne) then we're spending 6 months along the west coast in warmth.
I did pretty good this job in the shed, everything seemed to be on hand for a change. Usually I stand there wondering why I went there !!!
I did pretty good this job in the shed, everything seemed to be on hand for a change. Usually I stand there wondering why I went there !!!
I know what you mean, just remember before you shut it down to give it a few minutes at least above half throttle so burn off any soot build up, I never run mine at the low setting. I also give it a 20 min burn about every month or so to keep it happy and always keep fuel in the tank, I don't bother draining it and being heater fuel its age is irrelevant.
My instructions also did not have priming instructions did a google search on startup there is button sequence to prime her up - don't run the sequence twice as a second prime will fill the burn chamber and exhaust with raw fuel _ this makes for a very smokey start. No mozzies for miles