fireram

I have done several searches, but have not come up with solution yet..

Couple weeks ago started having hard time starting, when the temp got low.

It is obviouse that the grid heaters are not coming on, no drop in volt meter at all, and lots of chuggin and smokein when it finnaly dose kick.

I will take out the IAT tommorow and give it a cleaning.

Called local dealer, they ordered me a part, but it was all plastic, and certainly would not have threaded into the intake manifold.

Just wanted to ask, how do I check the sensor once it is cleaned, I read somewhere to put it in a glass of warm water and check resistance?????

Thanks..

infidel

Did you check the small trigger wires that slip over the posts on the two relays a little to the rear and below of the driver's side battery?
They have a tendency to come off.

jrs_dodge_diesel

Don't use water. This sensor measure air temp, not water temp. I would grab a heat gun or a hair dryer and warm up the sensor. Get a ohms check cold, warm, and hot. If this sensor requires power to work then you may be out of luck. Cleaning is a snap, just use brakeparts cleaner, it leaves no residue.

fireram

Today I took out the IAT, it was a little dirty, but looked fairly well.

It was warm when I took it out of the intake, and measured around 11 ohms. After sitting in the cold awhile, it measured 18 ohms. I happend to have and IAT from a 94 CTD. it also measured 18 ohms cold.

So I am assuming that it is ok???

I checked the wires to the solenoids, they are all clean and tight.

Has anyone done a meter check on the solenoids or grid heaters???

If so what should I be looking for?

I believe the computer knows it is cold, becouse the wait to start lights up and stays on for about 25 to 30 seconds. But there is no drop in the volt meter.

I would just like to know if i should order new solenoids, or grid heaters, both of wich i am sure will not be cheap??

Thanks...

Shovelhead

I'd take a volt meter and see if you were getting power to the grid heater contacts on the intake.
If not, it could be a bad relay or fuse.

fireram

I just tested voltage to the grid heaters, Nothing to iether one when the wait to start light is on.

Is there a fuse or relay for these? I could not seam to find one under the hood in the control box, or in the cab fuse panel.

there is 12volts going to the solenoids. they just arn't turning on.

There are four wires coming out of the wire loom that go to the solenoids, two to each one. They are clean and tight.

Dose anyone know how to check the solenoids?

thanks....

infidel

Use a jumper wire in-between the + battery terminal and one of terminals where the smaller trigger wires attach on the solenoid. You should hear it click and get voltage on the grid side of the solenoid. If this works the problem is with your IAT or PCM or the wiring to them. If the problem is the solenoids, though it would be very unusal for both to go out at once, you can replace with a Ford starter solenoid, $10 from any autoparts.

fireram

I got a chance today to try the jumper wire from + terminal to one of the smaller wires on the solenoids.

I put my volt meter on the big terminal comming off the solenoid, no juice, but the solenoid dose click. If i jump power to the other solenoid terminal, nothing at all.

So I will be ordering 2 solenoids from ******* tommorow. I tried to get two today, but the parts guy could not find them on his computer, no suprise, they could not even find the IAT sensor. They sent me some all plastic thing without even threads.

I will probobly have to goto major dealer in arthur, where somebody knows what they are doing, sorry for the rant....

Thanks for the help with this, Hopefully it is just the solenoids...

Shovelhead

Did you check the 2nd part of Infidel's post about using Ford starter solenoids?

infidel

Ford starter relays(sometimes called solenoids) are a great deal when you need a high amp relay. Ford used the same exact relay in every vehicle they made from the introdution of 12 volts until the late '80s, common and cheap. Think the dealer wants something like $42 each for the grid relays, if you can get them to find the p/n. Any autoparts worth anything will have Ford relays.

CDRAM

The ecm itself controls the grid heater circuit by reading signals from your iat, map and your vss(vehicle speed sensor). The ecm provides a ground to turn your wait to start light on. I would keep going the route that your on, but if that doesn't fix the problem, I would remove and clean your connections at these sensors, plus your 11 and 14 pin on the fire-wall, plus the ecm, and your 43 pin oem at the power distribution panel. Hope this helps.

fireram

Ok, I have the day off today, just called the parts jobber, he is looking in to getting two ferd solenoids, if all goes well i will have them in this afternoon.

Thanks again for all the help..

Fueling around

I thought the relays have +12 volts whenever the key is on and the PCM grounds the coil to trigger?

I've been having starting issues the past couple weeks, too. Most times it starts fine, but sometimes it is a bugger. Today it started hard even with subtropical 10°F temps.
The relays will get replaced this weekend as I did hear one squeal yesterday. I've noticed the alternate grid heater cycling doesn't always function. Hoping the power relays fix the issue.

CDRAM

That's what I thought in the beginning too, but according to the wiring diagram, on a 2001.5. The black wires with a white stripe connect to the ground terminal underneath the drivers-side battery. the yellow with black, and the orange with black are the 12v triggers for the relay. The ecm provides that 12v during the start process. If you want to test the relays, or bypass the ecm, just run a momentary switch to the terminals of the relay from 12v from battery. They should cycle, but it will through a code. That is if you do it with the key on. The other neat thing I have seen is the fusable link wire that is the main power for those relays, they can burn out, you will get a 12v reading but they cant pull any real current through them, this wont allow the grids to come on either. you will see these connections are at the drivers batt, positive terminal. Please post what the fix was, when you get it figured out. i always want to learn new stuff.

infidel

John, at some point, not sure when, most of the trigger circuits switched from negative to positive. Your '97 might be positive.