Voltage problems

[rustic]

I can see uses for the timer but I cant see it being useful here unless I'm missing the point (please point out if I am :doh ) as the need for the glow plug to operate is temp driven and controlled by the thermostat ?

The purpose is to reduce the "on" time, so that it won't overheat the glow plug and burn it out. The thermostat will switch the power off when the temperature is high. If it is switching too often, then reducing the "on" time via the circuit will reduce the thermostat switching.
In extreme winter the thermostat may not even cut out, so you would have to increase the Timer's on cycle (duty cycle).
The circuit acts like a light dimmer, reducing the overall average power.
Re: glow plug:
With the glow plug heating, how does it transfer the heat from the plug to the block ? When they are in the engine, they are in effect "air cooled" surely when in the block they would burn out without some form of cooling.
A heat transfer paste would work, mentioned in an earlier post, but this would expand on heating unless vented. Was there anything on the original plug?

 

[Deleted account DD]

I can see where youre coming from on this :thumb2

But surely if I restrict the glow plug/thermostats option to switch on by denying power to it by instilling an on off timing cycle using one of those kits, it'll often never reach the required heat exactly like central heating early or late on when you hear the thermostat go click to switch on but as youve effectively switched it all off because the timers set to off it cant:nenau

The block plug idea is a pretty efficient theory the plug heats the block which is tucked out of the airflow under the bonnet, the whole assembly is cooled by the fluid through it.

The glow plug is now (wasnt with the original) bedded in a generous amount of heatsink paste, the original was a very tight fit into the machined hole.

According to tech types I've asked who "know" glowplugs theres no reason why it should burn out so long as something be it oil or metal is acting as a heatsink.

The block itself shouldnt overheat because the thermostat cuts off the glow plugs heating efforts :nenau and its not located under the bonnet anywhere that can heat it up.

I've also contacted several people who've bought the same unit and so far I'm the only one who's had the plugs go

The fact others units are working no probs suggests the glow plug/thermostat/blocksize match is ok :thumb2

I'll happily accept it if theres a reason this is a crap design and bin it but that doesnt seem to the the case


Its a good un :thumb2 :lol

 

[aggas]

Aggas thanks for the figures, is the regulator an easy replace? I take it its 100% diode pack and not an adjustable regulator fitted (so I have no get out :augie )

Again thanks all :bow

Yes it is!! An electrician can do it in 20min.

 

[Deleted account DD]

After all of that, and a bit of a steer if anyone else ends up with one of these things.

After just over 2 1/2 weeks the bosch glow plug is still working away cheerfully. (if nothings the kiss of death saying that is !!!)

It looks as though I was dead unlucky with 2 dodgy glow plugs :nenau

Mind you being the cynic I've got a spare glow plug and a new tube of heatsink handy