Hello all,

Living in Utah it's been pretty cold as you can imagine. As of late, when I go to start the truck in the morning, the heater will not start right up (it's in the on position), nor blow until....I shift into any gear such as reverse or drive. Just as soon as I shift...bam...I've got air a blowin'!!! I've noticed a few times it doesn't do this during the afternoon (maybe because it's a little warmer?!?).

Does anyone have any clue why this would be happening? Or where I should start looking first? It's not really that big of deal, it's more of a nusiance thing than anything I guess.

Another thing I noticed around the same time is that my shifting lever is "a little bit" difficult or sticky to get engaged right at first. Both of these items just happened a couple of weeks ago when it started to get really cold.

I am just about to do a major tune up to the truck so maybe that will help? It is in a desperate need of one, that's for sure.

Thanks in advance for your help!

 

I think your ignition switch isn't returning completely to Run after you start the engine. And that leaves several circuits without power. But, when you shift into gear the lockout that is supposed to prevent you starting the engine in other than Park or Neutral is bumping the linkage just enough to bring the key to Run.

That's a very common problem with these trucks, and all it takes is some cleaning and lubrication of the switch and/or linkage. I explain how to do that on this page on my web site: Ignition Switch - ???Gary's Garagemahal.

 

X2 what Gary said. At the same time that the blower is not running [cold initial start], have you noticed that the gauges [oil pressure, fuel and temperature] as well as turn signals and possibly radio are not working?

 

Gary...you rock!!! Thank you!! I will try that and report back next week!! Thanx again!!

1986F150six...
Thank you as well!! You know what...every thing else functions as normal. Gauges all work, I couldn't see any other issue besides the heater issue and the shift lever but I wasnt sure if it was coincidence or not. They just happened at the same time.

Thank you both. I'll post next week after I pull it apart.

 

Don't pull anything apart just yet, try jiggling the key towards your body a bit after you start the engine and see if you can control the behavior via that.

 

Yes! That's the first step and one I should have stressed.

 

Ok...thanks so much Chris, I'll give that a try next time it happens. It just started snowing again today and it sounds like it will be doing that throughout the next few days. So now that it has warmed up a little bit, it doesn't seem to do happen in the 30 degree weather. Thanks again guys. I'll post back.

 

Following this thread....

 

Soooooo.....I didn't think my truck would do it again today where it's a little warmer, but it did and you called it Chris....

Started it up....and no heater initaly. So before I dropped it into gear I turned the ignition lock cylinder just a hair and blamo....the heat kicked on. Turning it back towards the engine just slightly, the heat kicks right back off. So I guess it had nothing to do with whatever temp is in the air huh!?! (and this is why I'm no mechanic...lol). I'm just noticing it because it's so cold and i am running the heat 24/7 when I'm in the truck.

Anyway...you guys all rock!!! Thanx for the diagnosis and it looks like I'll be ordering a new lock cylinder today.

Thanx again and happy trucking!! Take care and drive safe!!

 

It may not be the lock cylinder. Please go look at the page I linked to. There's lots of linkage as well as the switch, and all of it has old grease in it. When the temp gets low the grease hardens and the key doesn't return to Run as it should. That is very common and can usually be fixed with lubrication, not new parts.

 

Oh ok...i will do that first then.

Absolutely great site by the way Gary. I have visited on several applications in the recent past. I may have additional questions once I start diving into this. So thanx in advance for helping out us YouTube/Website mechanics..... . I really do appreciate it.

 

It does have something to do with the temp in the air. When it gets cold, the old grease in the column and the switch get's stiff, and aggravates the problem. You have to push against a spring to turn the switch to start, and you rely on that spring to put the switch back in the proper position. The cold weather makes the mechanism stiff and the spring can't quite overcome the resistance.

I drove mine for years like this, I got in the routine of wiggling the switch a little bit after I started the truck. I found myself doing this in every vehicle I started by habit.