Diesel pre Heat problem

Post by **Jon** » 24 Feb 2003, 15:04

P Reg Berlingo 1769cc with Keypad immb.
My neighbour asked me to look at his van over the weekend as it would not start. The glow plug light shows for about 2 seconds, but there was no feed to the glow plugs when I checked.
I therefore fitted a new Preheat relay of the correct type, but absolutely no difference. Checked all fuses both under bonnet and under the dash, but all OK.
Tested new relay with a voltage meter, and established 12v live at post one, and nothing at post 2 (supply out to glowplugs). At the 5 pin multiblock on the timer unit, pin 3 gives an ignition live. It would appear therefore that the timer relay is not being energised with an ignition supply.
I started the van by using a lead from battery postive to the glowplugs after turning on the igntion and using the keypad.
The only other component in the circuit which may be related is a 6 pin relay on the bulkhead next to the fuel cut off switch. I believe this relay to be part of the immobilisor circuit. Disconnecting it with the engine running stops the engine. This relay is shown on the microfiche as being part of the Preheat circuit. I have ordered one from Citroen to see if it makes any difference.If its is no better after this, I'm not sure which way to go with it.
Has anyone experienced anything similar on diesel vehicles with the keypad immobilisor?

wheeler · Post by **wheeler** » 25 Feb 2003, 04:53

what about the plugs themselves ? iv had a few (especially on DW8 engines) where one of the plugs is shorting out internaly.it causes the same symptoms,no output from preheat realy & just a quick on then off warning light.remove the lead from post 2 so it is not connected to the plugs then see if it gives an output,if it does i would say theres a faulty plug.I would then remove the rail from the plugs & check them individualy with a live feed and see if there is any exessive sparking.i cant see it being anything to do with the immobiliser if you can start it when you feed the plugs direct.

Post by **Jon** » 25 Feb 2003, 21:33

Unfortunately, theres no output from the Glowplug timer relay even when its disconnected from the Glowplogs!
Relay which I suspect may be at fault (the one thats also something to do with the immobilisor but is shown on microfiche as part of the Pre-heat circuit) sholud arrive today. We will fit it tonight.
If no better, its off to the Auto Electricians I suppose.

Post by **Jon** » 03 Mar 2003, 14:35

Hmmmmm, well I changed that other relay, and it made absolutely no difference at all! [:(!]
Now going to try another ignition switch. As I say, can't see any burnt out wires or blown fuses, so this is all I can think?
Anyone else experienced this problem on a ZX or Xsara which uses similar set up[?]
Confused, Swindon

tomsheppard · Post by **tomsheppard** » 03 Mar 2003, 15:36

I am sorry to hear that Swindon is confused and would reccommend bypassing the immobiliser which has a tendency to be troublesome and erratic. If you can find the supply pin to the relays, then it may be useful to wire directly from the battery at each stage and find out where you need to have 12 volts to get it working. This will tell you how far back in the circuit the fault is. Good Luck.
Tom

wheeler · Post by **wheeler** » 04 Mar 2003, 02:16

if the ignition 12v feed is missing at pin 3 why not just cut the dud wire off leaving a couple of inches on at the relay end & feed it off another ign live which can be found in the underbonnet fusebox.

wheeler · Post by **wheeler** » 03 Apr 2003, 02:13

just curious to know if you fixed this Jon[?]

Post by **Jon** » 03 Apr 2003, 14:39

Yeah its fixed.
Turned out to be a break in the Loom where it runs past the battery towards the bulkhead. No reason at all why this happened, the plastic trunking was intact over the loom, and it had not chafed. No other wires were affected either.
Only found the problem by chance when trying to trace the loom back from the preheat unit to the fusebox!