L3240 Hard starting

bwmarine · Dec 28, 2013

Ok, this fall noticed it cranked longer than normal before starting... now that its cold it takes a lot more cranking before it fires. The glow plug light turns on... but thought to check power at the plugs. Found no power getting to the plugs. Thinking maybe relay? Got a parts breakdown from merricks and it shows 2 relays for the plugs which are buried behind dash. Called local dealer and talked to mechanic and he thinks relay but he said could be controller or temp sensor. Anyway, ordered relays as they had none in stock and going to try that first. Wondering why 2 relays? One for light and one for plugs? Anybody ran across the issue I am having?

vrmnthntr · Dec 28, 2013

Question. Does it turn over slower like the battery is weak or just crank longer to start?

My L3540 starts like a weak battery but the battery is OK. Just started this winter.

bwmarine · Dec 28, 2013

Spins over as like always, It stays in my shop at 50*

Chilly807 · Dec 28, 2013

Too bad you can't check to see if there's power going to the relays.

Sean

bwmarine · Dec 28, 2013

That's what I was thinking... Have to pull dash apart to get to them. Think I will wait until I have the relays before I tear into it

Oiltech · Dec 28, 2013

2 relays are probably due to electrical load required to the glow plugs? One relay can only handle so much current

Chilly807 · Dec 28, 2013

If you knew where the wires led from the relays, the other end would work too. Sounds like a wiring diagram is in order.

Sean

bwmarine · Dec 28, 2013

Wiring diagram would be nice... think in the very near future acquiring a service manual : /

k0ua · Dec 29, 2013

For what it is worth, I don't have a manual for the 40 series, but the previous series the 30 series, has only one relay for the Glow plugs. The coil of the relay is controlled (ground side) from the Intellipanel (micro-controller), and the relay coil is fed by a 7.5 amp fuse. The relay contacts are a 40 amp slow blow fuse that is behind the main 60 amp fuse off of the battery. I sure would check both of those fuses before I tore the dash down to dig out that Glow plug relay.. and why it would have to have 2 relays on a 40 series is beyond me. Could the mechanic be mistaken? Sorry I cannot be of more help.

James K0UA