Cold starting question

[Hemijoejr]

I am working on an 1989 dodge W250. The grid heater dosn't come on until about 20 deg. I went to my local Dodge dealer and they looked at me as if I had 2 heads. They don't have anything on a truck that is over 10 years old. I have been looking for info on this problem for a few months and have turned up with nothing. If I had a few voltage specs to check or some ideas I would be grateful



Thank You!!!

Joe O'Cone

 

[BushWakr - RIP]

Hey Joe..... WELCOME TO YOUR NEW HOME... .



The heaters start to function at approx. 59*F or LESS.

The 'wait to start' light on the dash will come on, when the key is turned on. It comes on and "self tests" then goes out. If it stays on then the temp sensor in the intake manifold has signalled that the heaters should be running. When the heaters run, you'll hear a "clunk" from the heater relays, mounted on the drivers fender. There are two of them and they have heavy black wire running to/from them.

The heaters will come on, alternator guage does a nose dive, then they go off and wait to start light goes out.

If it's really chilly, then after the truck is running the heaters will cycle on/off, on/off, etc till the engine starts to warm.

Now, I'll look in the manual for the current draw on the heaters, but it is a lot of juice. A good battery and 120A alternator works their butt off feed that hearter assembly.

If you look at your intake manifold, just back from the air supply "horn" on the intake, you'll see two sensors. One right close to the "horn" that is the "intake air temperature sensor", the other sensor is closer to the firewall, and that one is a temp sensor for the KSB solenoid.

These sensors are generally the most likely fault on the heater/ksb circuits. Occasionally the heater grid and or the KSB will fail, but usually it's the sensor(s).



I hope that is some help, and in the mean time I'll dig out the manual and look for current draw values. If I find them, I'll come back and edit this post for you.



In the mean time, go over your connections if you haven't already done that. Make sure there is NO loose or pitted connections, especially the ground connection(s).



Bob... .

 

[jdurham]

hemijoejr,



Check this thread out https://www.turbodieselregister.com/forums/showthread.php?threadid=63789&highlight=IAT+sensor



Hope it helps!



Jim

 

[dpuckett]

Hemijoejr-

Seems like I remmeber reading somewhere that the intake heaters on some of the first ones (89-90) didnt come on till some ridculously low temp. I was thinking it was in the 25-30 deg range. THen they had a recall or TSB about it and replaced the sensors to get them working in the 40-60 (?)deg range. My early 91 doesnt heat as soon as the 92-93's I've had, but it seems to start and run fine. I'd say if you dont have to crank on it for a long time- <4 sec- and it starts and runs ok, dont worry about it too much. But OTOH, if it is hard to start or sputters and coughs after starting, I'd look into it deeper.



Daniel

 

[Hemijoejr]

Thanks people any help is appreciated

See, this is why you ask the people that own them! I got alot better response from you than at the dealership!!!

THANK YOU!!!!!