Checking, Glow Plugs. 2. Removing
the Glow Plug 3. High
Level Stop Light. 4. Rear Light
Assembly Faults 5. Double
Horn Modification 6. Horn Location.
Servicing a diesel engine can be a daunting task,
and is usually best left to skilled technicians at the Peugeot garage.
you are having starting problems, also large amounts of Black smoke
when starting. Then it's possible you have Glow Plug problems.
How do you know? and how are you able to check them.
engines rely on the heat produced by the cylinder compression of the
air intake. Diesel engines need glow plugs to enable easy starting of
the engine and the heat produced by them.
glow plug is fitted in the cylinder head and protrudes into the
combustion chamber. When activated it sometimes produces temperatures
in excess of 700C. In the newer engines the glow plug is
allowed to continue heating up after the engine starts to reduce the
important to fit the correct type as they protrude into the
combustion chamber. A short one could hinder starting and a long one
could damage the cylinder head.
plug is a miniature electric heater. While monitoring and waiting for
the dashboard yellow light to go out, prior to starting, you are
heating up the cylinder. Which in turn allows the diesel to burn more
easily, when introduced into the cylinder by the starter motor.
possible to check these 12Volt operated heaters very easily.
someone to operate the ignition key and check the voltage is present
at the nut heads of the glow plug, and it turns off automatically.
off the nuts which secure the electric cables at the tips of the
glow plugs. If like mine after 5 years of not having had any
attention, the screw threads were rusty. Soak the nuts with easing
oil a couple of days before. Remove the glow plug cable. While
the space is confined, it is quite easy to carry out this work. Glow
plug number 3 has an extra cable to it. This is the supply from the
activating relay, which turns on when the yellow light can be seen at
See photos below.
Glow Plugs 1 & 2
Glow Plugs 1,2,&3
the screw top of the glow plug is clear of the removed cable, place
a 12 Volt lamp device on the screw top and the other end to the
battery positive. If the lamp alights, then it's OK. No lamp
lit then it is possibly faulty. This test will indicate that the glow
plug is drawing current.
you have to replace any glow plugs it is better to change the set,
as if one has become faulty then the others are not far behind.
replacing the cables, check the resistance of each glow plug, a
value of 5 ohms or less usually indicates a good glow plug.
done the above test, replace the cables back on the glow plugs.
Ensure the cable spades and connectors are clean to give maximum
current to the plug. Place the crocodile clip on an earth point of
the engine and the test tip on the glow plug tops. Get someone to
turn on the ignition and to the glow plug start position. Check
whether the plug tester lights. This test will indicate that the
relay supply is OK and you have volts going to the glow plugs.
my drawing below for the test lamp which I use. This can be
purchased from many Motor Factors. It is basically a tubular
lamp inside a see through screwdriver handle. This lamp can be
used over the range of 3 to 24 volts. A useful device which can
be used for fault finding electrics in a vehicle. This must not be
confused with the Mains Electric tester.
glow plug tester can be purchased for £5.95 [Mar 03]
glow plug tester I used, is very basic and should not be considered a
comprehensive tester, just a tester which indicates the glow
plug has volts and is drawing current.
If after the
above tests and you still have problems then a change of glow plugs
might be necessary. After removal check the plugs, any burnt or
damaged ones will confirm your decision to remove them, but will also
give a clue to the problems.
Check and ensure the Glow Plugs are the
correct type for the vehicle.
Replaced with WELLMAN W631.
Tel:- 0121 553 4418
Damaged heater tube
Could be injector problem. Irregular spray
of the injector. Have them checked and cleaned or replaced.
Carbon on tube
Excessive oil in the combustion chamber.
Could be due to wear allowing to much oil into the combustion chamber.
Take care inserting and removing plug. Do
not over tighten. Use copper grease on the thread for easier removal.
Tube corroded or different colour to the rest
Coolant leak in combustion chamber. Check
for head gasket fault.
Tube has a swollen up
Could be caused by storage problems
giving a damp cylinder.
in starting, even after a glow plug change.
the ignition and check there is voltage at the cables feeding the
glow plugs. If none then the relay supplying the glow plug voltage is faulty.
Melted Heater tube.
Excessive alternator voltage. Alternator
not stabilising the charging voltage.
Injection Timing out of sync. check
Worn piston rings causing excessive oil burning.
Check control relay.
REMOVING THE GLOW PLUG
The changing of the glow plugs can be an
easy job for the competant DIY man, and also, if you have the correct
tools. I used a 12mm offset ring spanner to start the unscrew. Then
used a 12mm Ratchet ring spanner to complete the unscrewing. The
180Degree flexhead ratchet ring spanner will allow a small unscrewing
movement which is required in the small working space. [See the
pictures above] These tools can be obtained from Halfords in the UK.
The offset ring spanner is required as the
start of unscrewing is tough. You might find, as I did, that a tube
will be needed to go over the ring spanner to give extra leaverage
for the start.
Before removal, the electric cables
attached to the plugs must be removed using a 8mm box spanner, or a
ring spanner. Be carefull when removing the nuts from the plugs. They
are easily lost and must be found to avoid these items getting into
parts of the engine perimeter which can cause a costly repair. I
dropped a plug and it took me an hour to find it! In my previous job
a mechanic lost a spanner during a service. It was found a week later
in the timing belt cover, after the timing belt had been stripped of
Here can be seen the glow plug removed
after 10 years use
New glow plugs replaced with Wellman W631
High Level Rear Stop Light.
of my first modifications to the Motorhome was the High Level Rear
Stop light. This is a requirement by law in new vehicles. While not
retrospective, I did feel as the rear lights were low down this could
be good safety feature.
light fixture was purchased from a well known vehicle spares
supplier, Halfords. The fitting had a narrow tubular structure, which
made it an ideal fitting between the blinds and the rear window. It
was screwed to the top of the window aperture. The cable was then fed
behind the blind fittings and down the wall to the rear light assembly.
cable was fed through a hole in the Motorhome base, then to the rear
light assembly point, which was fed inside and connected to the stop light.
High Level Rear Stop light is bright enough
to be seen from behind the shaded type rear window of the Motorhome.
See images below which illustrate the fitting of the light.
haven't shown the wiring diagram as it is just a case of taking the
wire from the stop lamp to the rear cluster, getting someone to press
the brake light and making a note of the lamp which turns on. Then
connecting the wires to that lamp.
The High Level Rear Stop light
Rear Light Assembly Faults
---- Original Message -----
From: Chris Watts
To: brian [ at ]eclipsehistory.org.uk
Sent: Sunday, March 07, 2004 1:13 PM
Subject: Triffic Trafics
I have been looking at your site with
interest for the last six months, I realize you have now changed from
Renault, but I wondered if you could help me I have just traded my
very tatty and tired 1995 Renault trafic T1100 diy conversion I
bought privately for an older one in brilliant condition from a
dealer, a 1990 Renault trafic T1100 Holdsworth Romance
with the same 2068 litre diesel engine and the mileage being
only 49000 with the full service history. I have only had it a
fortnight and the brake lights have stopped working ( that's if they
were working when I bought it!) I have checked every fuse in the fuse
box, also the brake switch and there is power both sides when pedal
is depressed. Both bulbs are ok and I am now completely stumped. With
everything you done on your Renault, and realizing it was petrol I
wondered if you ever worked on the brake lights? and am I missing something?
yours very frustrated Chris Watts.
Many thanks for your email, it's always
nice to hear from people who have been to my site. While I have sold
my Trafic I still keep the site up to date!
The guy who built the Holdsworth now
writes for the Motorhome Magazine, not MMM, and has been known to
pass on information about dealers who are prepared to give advice or
repairs to his old vehicles.
I wonder if you have come across the
www.rtmr.org site[ Renault Trafic Motorhome Register.] This site is
dedicated to all Renault van owners. The Technical genius is John on
Regarding your problem. This is a classic
and I have had a number of queries from others with the same fault.
None have come back to me and confirmed my advice!
My advice was to check the black wires
which form part of the earth returns of the cable harness on the rear
light assembly. make sure these are clean on chassis, as these
negative wires are as important as the live wires.
Check the negative wires inside the rear
light assemblies to chassis with a resistive reading meter, should
read a maximum of one ohm.
Take out the lamps and clean inside the
retainers, make sure the white surface gunk is cleaned out.
On my own vehicle, I made a separate cable
return, from where the negative cables were strapped to the chassis,
to the front of the vehicle and secured it to a good earth point. I
then placed another cable from this point to the negative terminal of
I'm assuming of course that the brake foot
switch is sending a 12volts to the brake light assembly at the rear
of the vehicle.
Hope this helps. Let me know how you get on.
By the way you will find further ideas and
help in my other web site; www.ourwanderer.org.uk
Double Horn Modification
horn on the Wanderer is rather feeble. So I have introduced this
modification quite cheaply.
original horn switch on the steering wheel, places an earth on the
return path of the horn. So at the horn you have voltages on each
socket, if checked.
relay was placed in the horn position. The relay contacts will
receive battery volts from an introduced fuse box, then feed the two
cables which fed the horn, and are now used for the relay, they are
then placed higher up into the engine compartment to eliminate any
water ingress to the relay.
old horn was discarded.
two horns were purchased from separate dealers to ensure each horn
had a different sound. They are described as 'Trumpet' horns. It is
possible to purchase horns with different tones! Tones are 410Hz &
510hz. [The Hz means 410 cycles per second.]
components purchased were:
horns, one relay, and some spade receiver connectors.
sounded, the horns now turn the heads of those who hear them!
who don't want the extra sounding horn, then just use one. The
circuit drawing will be the same, minus one.
Physical images of modified horns
of the Horn
The horn, Ah! Located on the
passenger side of the vehicle, right underneath the headlamp, you
will see the horn hidden under a chassis lip. The only way to see it
is to lie down under the vehicle, immediately under the passenger
side headlamp. Then look up at the headlamp. You will probably see
the cable running to the horn before you see the horn.
A previous letter to a Motorhome magazine
mentioned the contributor had had to remove the front bumper to do
this work. I did not find it necessary.