'09 E-250 Heater Fan

[mchan68]

Supposedly, this customer complains of the heater fan stops working intermittently under random conditions. On the two prior visits with the same complaint, neither myself or the other technician was able to recreate the symptom. My service manager even asked me to drive the vehicle home for a night for this. Vehicle is a 2009 E-250 with a 4.6L if it matters. No SSMs or TSBs in OASIS for this. Anyone else run into somthing like this?

[Alex Bruene]

I am aware of 2 Rogers Econolines cruising around with the same complaint. We've never been able to duplicate it. I told them to go out and smack the blower motor if it happens again. And if it starts to work, I'll replace the blower motor for them next time they come in. If it doesn't, I'll have a good idea of what it isn't.

[Aaron]

Mikey Chan - The Van Blower Fan Man.

[Bruce Amacker]

This sounds like a connection or relay problem, so a voltage drop test on the power and ground side might be in order. A weak connection or relay would commonly show excessive VD even when working, and the fan might run just fine in this situation. I do have a couple of suggestions to test the motor- do an amp test and compare it to other known good units, or compare it to the fuse rating on the circuit. Amperage is usually about 3/4 of the rated fuse on high speed. If it's binding it will be close to the rated fuse, and if it has an open winding on the commutator it should be lower.

 

The best test would be using a low current clamp and a scope. The clamp can be purchased for under $100 and is WONDERFUL at locating open windings in fuel pumps and other motors, just to name a few tests (gas injectors, ignition coils, zillions of cool uses!). If the motor has an open winding it will work fine most of the time until it comes to rest on the open winding, in which case it won't start- like the fuel pump that needs a whack on the tank to get it started.

 

I have tons of cool waveforms showing dropouts if you need them, the amp wave drops near zero every few milliseconds with a bad spot in the commutator. This is a really cool test and would make a scope freak out of you if you tried it, an amp clamp should be a required tool in any shop that has a scope or VMM.

 

Good Luck!

 

[Aaron]

VMM comes with an inductive pickup, doesn't it?

[Bruce Amacker]

Dunno. The only one I've used was at the TC. I don't have one (and for $5G I won't be getting one soon!) Are you sure it's a low amp clamp and not a secondary pickup or trigger lead? They look identical.

 

[Aaron]

I'm not a hundred percent sure, but I thought it came with an amp clamp, but it may be a HIGH amp clamp, for testing alternators, and shit.

[Shlep]

Comes with 2 of them, a 50 Amp and a 500 Amp.

[Bruce Amacker]

Cool! The 50 amp should give you a great motor waveform. Has anyone tried it?

 

[Jim Warman]

The VMM is (at one and the same time) great and a POS. It is really decent as far as capabilities are concerned... it is vastly different from the cartoon we had in the WDS (but you still get "Run, Gumby, run!!!"). However, the setup time can be a tad daunting as is the mess of cables. I'm sure you already know that the VMM has to connect to the IDS (one cable), to the vehicle battery (cable number two) and to whatever it is you are measuring (cable 3 and likely cable 4). The tech will more than likely have the IDS connected to the DLC though it isn't necessary for most scope functions (but I wanted to mention cable number 5).

 

Having said that, there are some very good preprogrammed tools (my brain is very much on holiday but most of the tools are covered in the tech notes...) tap the IDS tab on the top left, the Swiss army knife tab at the bottom and finally the tech notes in the right column and the blue tick... <POOF>

 

Whoops... haven't used the amp clamps yet but I think we are very close to needing them badly. I think some techs in the aftermarket use current ramping quite a bit.