# heater plug or relay



## shaunwelder (Mar 29, 2008)

hi guys 
got a problem with my fiat ducato 2.5td 1990 motorhome
when i turn the key the heater light for the glow plug comes on and off very fast if you blink you would miss it. 
the glow plug is not heating up long enough to warm the fuel dont know if fault lies in heater relay or glow plug,there is only one glow plug on this engine and it is placed on the top of the manifold.
i have cleaned all connections to relay checked for dry solder joints,             
checked the glow plug when hard wired to the batterythe heater plug it takes about 4 to 6 seconds to smoke and about 15 secs to 20 secs to glow red.
when replaced back into the manifold loosely and turn the key there is power to the plug but power does not stop on long enough for the heater plug to smoke or glow red.
can someone help please........


----------



## AndyC (Mar 29, 2008)

Does it start OK?

The old 2.5TD Fiat engine doesn't normally need a lot of heat. Our old 1991 Fiat only held the heater plug on for any length of time when the outside temp was below zero.

AndyC


----------



## David & Ann (Mar 30, 2008)

If it starts okay, don't worry about it. My last MH. a 1992 Fiat Ducato, the glow lamp would flash and go out as soon as I turned the key, engine would start immediately even in the depths of winter. If everything is woking smoothly, why worry about it.


----------



## shaunwelder (Mar 30, 2008)

*reply*

ok guys
if the engine would start first time
i would leave as it is but it dont if take about 3min contin/turning over
and if its cold it would take longer ot start


----------



## lenny (Mar 30, 2008)

I would try a direct feed from the battery to the glowplug, by- passing the relay for 5 to 10 seconds, if this starts the engine then the relay is suspect.


----------



## shaunwelder (Mar 30, 2008)

*reply*

hi 
ive tried hard wiring from batt/with the glow plug out of engine and it takes about5 to 10 sec to smoke and about 10 to 20 sec to glow red .
but i dont know wot else the relay controls.
so until i know wot it control i dont want to  put a switch to the plug just incase i blow somthing else
so need to find problem really.................................


----------



## lenny (Mar 30, 2008)

Had a similar problem with my vw years ago so I borrowed my mates relay and it solved the problem, trouble is , he wanted it back so I had to buy a new one, I'm pretty sure the relay determines how long the glow plug receives power, just like a timer switch,then cuts the power when the time is up.


----------



## shaunwelder (Mar 30, 2008)

*reply*

yes thats wot i think as well
then it could be the plug that taking two mch time to heat up.
dont know how long it should take for the plug to heat up////////////


----------



## walkers (Mar 31, 2008)

shaunwelder said:


> yes thats wot i think as well
> then it could be the plug that taking two mch time to heat up.
> dont know how long it should take for the plug to heat up////////////


does sound like the relay, have you checked if it is heating at all when connectyed to the relay?


----------



## avandriver (Mar 31, 2008)

shaunwelder said:


> hi
> ive tried hard wiring from batt/with the glow plug out of engine and it takes about5 to 10 sec to smoke and about 10 to 20 sec to glow red .
> but i dont know wot else the relay controls.
> so until i know wot it control i dont want to  put a switch to the plug just incase i blow somthing else
> so need to find problem really.................................



Change the relay and problem solved 

The heater circuit relay only controls the heater circuit that is why it is called the heater circuit relay 


Steve


----------



## janeandbob (Mar 31, 2008)

*Heater plug*

Hi shaunwelder
                    I have a 97 Ducato with 1 heater plug that only flashes once. I did put a reply on MHF but i see you ran out off post. I think you should be looking at changing the fuel filter and ckecking for a leak! minght be draining back and talking time to pump fuel up again. I dont think it is the heater plug or relay. Good luck Bob.


----------



## shaunwelder (Mar 31, 2008)

*reply*

hi 
its nothing to do with fuel/or filter.
if i wire the plug dir/to batt is starts first time even if its below freezing
with no problems
got a auto electrision coming out to have a look .i think its the rely

thanks


----------



## lenny (Mar 31, 2008)

Keep us posted on the outcome, Shaun, and good luck


----------



## shaunwelder (Apr 1, 2008)

*relay or heater*

right guys got it sorted
my boss at works got friends over in germany
who used to convert dethleffs mh/s.
the gray alian box called heater relay or bitron 2044029........
controls only the timer and shut off power for the heater plug (ONE PLUG SYSTEM ).....
he said if they had a problem with the briton  they would by-pass the relay and install a 40amp relay 40amp inline fuse and a pressure switch in the cab 
+ aprop/grade wire....................and must be a pressure switch so you dont leave it on.............
ive just purchased all above new for £20.00
before you install the above you need to check the glow plug to make sure its working to conferm that the relay is faulty
ill update when i install mine....................................
thanks
          shaun


----------

