oliver92

ok so i still have a check engine light and code shows air sensor..checked connections out as wanna said and all seems ok so i purchased one the other day..$23 and change..havent installed it yet but my preheater isnt working and i know most have talked about the cycling of the preheater after the engine is running even..my question is...why couldnt a manual switch be installed to trigger the preheater solenoid and then it wouldnt have to cycle or when the air temp sensor or something else went out it wouldnt affect the preheaters from working...the older diesel tractors had a push button starter switch to activate the preheater..so why wouldnt it work on these trucks as well..just food for thought..thanks for the replies and opinions

Greed 93

You could install a switch however if you leave it on to long you will likely burn up the relays or something just be carefull hook it up so the switch supplies a ground to the relays it already has key on hot.

Jammie Dodger

just thinking of this pre-heat button myself, i was thinking along the lines of a momentary switched wired into the heat sensor for the the heat screen.

or

just turn the ignition key twice to give two cycles of the heat screen.

dillenger1

Use a starter relay from a tractor with a momentary toggle in the cab

wannadiesel

A momentary pushbutton would work just fine. The solenoid coils get 12 volts from the ignition so all you need to do is provide ground.

oliver92

spring loaded momentary switch was what i had in mind also..jammie if the sensors arent working it wont preheat so cycling the switch wont work..least thats what mine is doing so thats what im assuming is the problem...if they are regular starter type solenoids why couldnt you just wire the switch to the relay post on the solenoids?that way you activate them manually..only thing then is if you go to 100% manual without them in the system will it trip your check engine light and it stays on..thanks again for the ideas and help

SNOWMAN99

I just read in the factory service manual for my 1993 you are not supposed to cycle heaters on and off. You are supposed to wait 15 minutes before you cycle them on after the first time. I am sure everyone cycles them on and off as needed and i have no clue why they want you to wait 5 minutes

Jammie Dodger

to go alongside the preheat button, it would be good to be able to turn a idle-**** to increase the rpm. on another diesel vehicle that i own this rpm increase is very advantageous for cold starts.

BRUISER

if you are talking about the grid heaters.. then yes you can put a button on them.. I have a push button on mine that I hold in when i first start the truck on cold days.. then when i release it stops power to them..

oliver92

bruiser how did you wire your momentary button in and does the check engine light stay on or throw a code..also does your fuel heater work along with it?..not sure how the fuel heater is tied into the circuit..thanks for the info

oliver92

ok when looking at the preheater relays are the blue wires running to each one the ground wires to activate them or the other 2..thanks

wannadiesel

Blue wires are power, leave them be. Pull off the other wires and rig those studs to your grounding switch.

oliver92

good deal thanks wanna it is working as should now that i have a new air sensor but dislike the constant cycling after startup so will probably bypass the factory setup..thanks again

wannadiesel

Oh, just leave it alone and let it work as designed. It doesn't hurt anything and it's good for the polar bears.