Heat stuck on, intermittent turn signals, overheating up hills

rw080761

New member
Hello all!
Im a novice so please bare with me and the following descriptions of my current issues with my 2005 sprinter van 2500.

All the buttons and knobs/rotational knobs seem to be stripped leading the heat to always be on. Seems like my options are to pull the dash apart and plop a new unit in? Or maybe attempt to just replace the knobs/buttons? Curious on other peoples thoughts on this.

Also the van runs mighty close to overheating up these modest Colorado mountains. Ive had to pull off on a few of the longer runs up. At least thats what the dash sensor is telling me. Whats slightly confusing is that same gauge says the van is operating at (a single white block above 110F when im coming down hills (so rather cold?).

How can I test to see if the gauge itself is broken? The vehicle does appear to be leaking coolant but ever so slightly. No entirely sure from where maybe the water pump as it looks a little wet. :thinking:

I've only ever seen the fan in front of the engine on once and that was recently. (technical name escapes me) Ive read that the fan on the very front of the vehicle in front of the radiator is for the ac compressor. If this is true then it would make sense why ive never seen that fan on as the heat is always on. (?)

The intermittent turn signal issues seems to be remedied by tapping (slapping) just under the steering wheel where the fuses are. Ive opened that box up a few times and none of the fuses seem to be loose but hitting that box cover when the signals cuts out as im sitting at lights seems to do the trick nearly everytime.

Could there be bad wiring preventing the fan to come on to cool the engine when its need on these massive mountain inclines? Could this be related to the intermittent turn signals... they seem to cut out quite often and smacking the box fixes it every time. Are the fuses perhaps just going bad? Could the heat being stuck on in anyway be connected to any of these issues?

thank you for your time!

RW
 

autostaretx

Erratic Member
First off, here's the 2006 service manual: http://diysprinter.co.uk/reference/2006-VA-SM.pdf
(close enuf for the 2005).
The heat will be "full on" if the valve involved is *not* receiving any power (it's a "fail safe" so that you'll have defrosting in the winter).

It is almost common for Fuse Block 1 to have "issues" ... the copper conductor bar can break free, leading to all sorts of conflicting/puzzling symptoms. The spring fingers that hold the fuses and relays can weaken and create intermittent contact.

The pulley-driven fan on the front of the engine has a thermal clutch ... as the engine area gets above 205 F, the fan engages. No electricity involved. When it comes on, it's loud.

The connections from the switches on the steering column go in/through Fuse Box 1's connector.
Fuse Box 1 also has some electronics on its back .. which may include the counter/timer for the signals.

--dick
 

Patrick of M

2005 T1N 2500 (NA spec)
Don’t know the history of your van, but if the PO was unscrupulous, pulling the thermostat innards is a way to try and mask overheating problems (and would also cause excess cooling on descents). Replacing the thermostat is a occasional maintenance item, but I would probably try to work out why it is overheating first.
 

Midwestdrifter

Engineer In Residence
Thermostats can stick in a specific position, especially if the coolant hasn't been changed regularly. I would need to double check the diagrams, but I believe the sprinter uses a bypass cooling system, so removing the thermostat would result in no radiator flow.

A failed viscous fan clutch can cause both over heating and over cooling depending on how its failed.
 

Larry M

Well-known member
...A failed viscous fan clutch can cause both over heating and over cooling depending on how its failed.
The clutch is a good place to start. Our 2005 was running hot going up hills and cool while going down. We had the viscous clutch replaced which took care of it running hot but it still ran cool going down hills. We then replaced the thermostat and that took care of the lower temperature swings.
 

Patrick of M

2005 T1N 2500 (NA spec)
Thermostats can stick in a specific position, especially if the coolant hasn't been changed regularly. I would need to double check the diagrams, but I believe the sprinter uses a bypass cooling system, so removing the thermostat would result in no radiator flow.

A failed viscous fan clutch can cause both over heating and over cooling depending on how its failed.
Wouldn’t a failed clutch fan cause over heating “or” over cooling depending on how it has failed?
If you remove the innards from the T1N 5 cyl thermo the coolant would flow through...unless I am very confused as to how it works.
 

Midwestdrifter

Engineer In Residence
The clutch can fail to fully lock, AND drag significantly due to bad bearings. This means it never reaches the minimum speed (max slip when cold), and it never fully locks. The extra cooling isn't really noticeable unless its freaking cold though.
 

Top Bottom