DAF LF45 starting problem

UK PROFESSIONAL DRIVERS FORUMS THE UK PROFESSIONAL DRIVERS FORUM (INTERACTIVE)
1

Hello! I need to pick your brains if possible please.

I have a '53 plate LF45 horsebox, used weekly. Went to it a few weeks ago, totally dead - nothing - as in turned key, no attempt to turn over, no clicking. Called mechanic, batteries were flat (despite isolators being off) - batteries replaced, isolators now off and out of the key hole totally when parked up. Assumed problem solved. Prior to replacing batteries, starting had been a bit rough - as in turning over and eventually firing.

Went out 29th July, started first time, normally (turned key, fired up straight away, not struggling). Drove for 20 mins, stopped for diesel - wouldn’t start, not even turning over - all lights/camera as normal, so definitely power there, just nothing happening engine wise! Tried phoning for help, no one answered - turned key one last time, fired straight up and drove normally. Drove to destination, parked - tried to turn back on, nothing. Competed, loaded up a few hours later, turned key - started as normal.

I looked online and saw some comments about the chip in the key dislodging. Tried the spare, fired straight up! Problem solved, I thought. Drove to Coventry, parked up for four days. Turned key to come home yesterday, nothing - one little chuffed from the engine, then nothing. Isolators off all the time we were away, no hook up, no lights used. Initial attempt was with spare key (which worked straight away at home), swapped to normal key - started.

I’ve got no warning lights, it’s running beautifully apart from this…does anyone have any suggestions/experience of the same thing?! Thank you for reading :slight_smile:

2

Shot in the dark could be the starter motor sticking,not quite the same had 61 plate FH starter went no warning lamps turned the key nothing at all.

3

Could it be the ignition switch? Loose connection or frayed wire.

4

Hi Marlowe ,

For the sake of 35 quid it might be worth either buying a hand held obd diagnostic reader to see if any fault codes are present or stored or asking a local workshop to quickly plug it in.

Secondly I would be looking at the fuel system ,if there is an air lock it wont even spin over , they commonly suffer from blockages and air locks on those engines , google daf cf fuel problems and I am sure there will be plenty of forums talking you through bleeding the system etc

Hope this is of some help and gives you a different angle to go down …

Good luck

5

Thank you for the replies.

My gut is saying ignition switch/ something electrical - it’s literally a case of “the lights are on but no one is home” - then two seconds later it fires up perfectly?!

Would a fuel blockage/lock affect it whilst running? It went loaded to Coventry and back, ran spot on and fuel consumption was normal?

I’ll look for a diagnostic tool too, I didn’t realise they were quite affordable!

6

I’d go look at the ignition switch too. Put a multimeter on the switch contacts on the rear and turn off/on several times.

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7

We had a similar problem with an Iveco ie starting OK then next time everything dead then next time start OK etc. On the Iveco it was caused by a small wire that runs directly from the starter solenoid back to the ECU / EDC. I think this is some sort of security idea in that if the ECU does not recieve a signal back from the solenoid it then disables everything and the truck is dead, stops the truck being hot wired ? Anyway, because this little thin wire goes from the chassis rail to the back of the starter the engine movement eventually causes it to break but then because of the engine movement a couple of strands might touch again and lets it start the next time. Hope that helps.
If you want to learn, the hard way, about fault finding on truck electrics buy an IVECo :laughing:

8

I know you’ve been down the immobiliser avenue but it still feels like something along those lines to me although I can’t remember if it will still crank but just stop fuelling when it immobilises.

The Iveco starter wire referenced in another post is definitely very common and can be intermitment before it worsens but not come across it as widespread on DAF.

As mentioned I would second getting codes read will safe a lot of fumbling in the dark.

9

marlowe:
Thank you for the replies.

My gut is saying ignition switch/ something electrical - it’s literally a case of “the lights are on but no one is home” - then two seconds later it fires up perfectly?!

Would a fuel blockage/lock affect it whilst running? It went loaded to Coventry and back, ran spot on and fuel consumption was normal?

I’ll look for a diagnostic tool too, I didn’t realise they were quite affordable!

Marlowe , I beleive my brother purchased a obd reader from amazon for around 35 quid …just make sure its coming from a uk dealer with decent reviews …

As own account driver said an immobiliser usually works buy cutting of the fuel , an air lock in the fuel rail would show the same symptoms and if its from a poor seal it would usually happen after an engine has run and is cooling down as the fuel will shrink in mass creating a slight negative pressure in the system so if there was any failed seals air would be drawn in.

Let us all know how you get on

10

Thanks all, I have a weekend of rummaging round ahead of me! Will let you know if/when problem is solved. Finger crossed!

11

As requested…an update!

So - spent the last few days asking lots of people questions…and getting no where. Asked DAF what they thought - response was minimum labour charge of £200 and they’d have a look! Spoke to an immobiliser expert (who was fab) but he said unlikely to be that. Emailed a diagnostic guy, he must be good as he gave me a date in September!

So - it was down to me. I’m not very technical. But, decided to start with the starter motor. I’ve always thought it was between ignition and starter motor, so that’s where we started. Luckily I fit in the gap between the wheel arch and the. Hassis (thank you divorce diet) so I could actually reach the starter. All looked OK, no chafing on the solenoid cable. I pulled the spade connector off, cleaned it,put it back in, got out from underneath…turned key…WE HAVE LIFE! Stopped and started it again, and it’s starting normally…I’m not one to count my chickens too early, but it seems like progress even if it’s not problem solved…!

12

Check the wiring loom. When you removed the connector you probably disturbed it and remade the circuit. Particularly check where it bends round where the cab tilts.

13

Own Account Driver:
Check the wiring loom. When you removed the connector you probably disturbed it and remade the circuit. Particularly check where it bends round where the cab tilts.

Own account os totally right ( not that he needs my approval lol ) …my wife has a vw sharan and had so many electric problems from speakers to cental locking to rear window wiper etc all caused by wiring loom bending in the doors !!

Tracing the wire you need isnt an easy job with out some “technical info - wiring diagrams” but once traced it’s an easy fix but expect more issues from the said wiring loom .

14

We had electrical problems on some of our old LF45s caused by chafed wiring. Anything from intermittent ECU warning lamps to (on the one I drove) loss of accelerator pedal function. As observed by others, simply disturbing the wiring would often cause the fault to apparently fix itself, only to return a few minutes/hours/days later.

The accelerator pedal fault even fooled a Daf technician. He plugged in his laptop, saw the reported fault and scuttled off to fetch a new pedal unit. All good - until it failed again with the same problem two hours later :frowning:

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