Rookie needs help please

[GMJim]

I posted this in general and was advised to try posting it here. Don't beat me up too bad. I have a 68 Chevy C10 with a Gen3 4.8 in it. I wanted to change my fan temps for fan#1 and fan#2 I managed to read the original file, save the file and make my temperature changes and write it to my truck. Afterwards I switched to the VCM scanner and started the engine and watched the temp rise to the fan 1 temp 210* and no fan? I then waited to reach the fan 2 temp of 220* and no fan?? I went to special functions on the VCM scanner to see if I could activate the fans and no problem. I have a fan overide switch that I used to cool it off so no over heat issue. I read the changed file to make sure my changes were there and they were. Any idea where I screwed up? I have not written the original file back at this point.
Help is appreciated.
Thanks
Jim

[gametech]

A story is useless without the tune file and an exact description of how the fans are wired.

[GMJim]

A story is useless without the tune file and an exact description of how the fans are wired.

Prior to my temp changes my fans worked fine with the old tune. How do I post my tune file here? Fans are wired to the ECM with a painless harness

[gametech]

After you hit "reply", look down and to the right to see "go advanced". Then you will have options to upload attachments such as your tune and a log.

[GMJim]

Thank you gametech!
I hope this helps.

[bk2life]

I then waited to reach the fan 2 temp of 220*

hey jim why not lower those on and off temps to like 180 on and 160 off and see if the computer turns them on and off

[GMJim]

hey jim why not lower those on and off temps to like 180 on and 160 off and see if the computer turns them on and off

Thanks for the suggestion. Because I didn't understand why my changes didn't work I didn't want to further complcate things and figured I would ask here on the forum before trying to return to the original tune or lowering temps. I have a ticket in at HP Tuners hoping they have a solution. I may try to write the original tune back in and see what happens. I'm new at this and am treading carefully!

[gtstorey]

Thanks for the suggestion. Because I didn't understand why my changes didn't work I didn't want to further complcate things and figured I would ask here on the forum before trying to return to the original tune or lowering temps. I have a ticket in at HP Tuners hoping they have a solution. I may try to write the original tune back in and see what happens. I'm new at this and am treading carefully!

HPT doesn't give tuning advice.

[Alvin]

The wires going to the PCM from the fan harness.. Try grounding them.. see if that turns on the fan. If it does then you know it's a tuning issue. The tune looks fine. I'll be this is a wiring issue.

[GMJim]

Alvin
Prior to changing the temps my fans worked perfectly with the old setting?

[GMJim]

gtstorey
Depends on how you look at it. I know that I did (I think) things correctly. It's what went wrong is where I need help. We'll see what they say.

[gtstorey]

gtstorey
Depends on how you look at it. I know that I did (I think) things correctly. It's what went wrong is where I need help. We'll see what they say.

Well, good luck. They usually won't help if it isn't something broken on their part.

[GMJim]

Well, good luck. They usually won't help if it isn't something broken on their part.

Thanks. If they can offer some suggestions that's ok but if they don't, I'll have to figure it out. The forums are a good source of information and I did a lot of reading before I invested in the MPVI3. This is all new to me and at 72 a little challenging with no moving parts. I appreciate all the help and suggestions.

[bk2life]

I appreciate all the help and suggestions.

it worked fine before and now doesnt.

if all you changed was on/off temps then lower them and try again.
you already stated you can command them and off through the scanner, so you know its not a wiring issue.

id lower the temps, do another write, unclick the high speed box, and see if they turn on correclty.

If no, then id suggest maybe there is a read/write issue, and id try a write entire, with the lower temps to see if the issue is resolved.

you dont need to do write entires often, but, sometimes it can clear up an issue at hand. -this appears to be a simple issue here, and lowering fan temps is not complicated, so there has to be an issue with uploading the file.

[GMJim]

it worked fine before and now doesnt.

if all you changed was on/off temps then lower them and try again.
you already stated you can command them and off through the scanner, so you know its not a wiring issue.

id lower the temps, do another write, unclick the high speed box, and see if they turn on correclty.

If no, then id suggest maybe there is a read/write issue, and id try a write entire, with the lower temps to see if the issue is resolved.

you dont need to do write entires often, but, sometimes it can clear up an issue at hand. -this appears to be a simple issue here, and lowering fan temps is not complicated, so there has to be an issue with uploading the file.

Thanks bk
I got a reply from HPT Tech support here: "Please flash the stock file back on and let me know if the fans come on as they should. If they do I would say it would be an adjustment in the file. If not it could have something to do with the override you have installed."

I'm going to flash in the old tune as HTP support suggested and see if it works, then try a lower set of numbers afterwards as you suggested. My 2006 Silverado LQ9 has very high temp numbers Fan#1 on 226 off 219. Fan#2 on 235 off 237. As I can't seem to find a factory 4.8 tune that has 2 fans, I figured using a number of degrees lower with the same spread would be ok but I'm using a 180* stat. I'll post back later with the results.
Thanks everyone for the help
Jim

[GMJim]

UPDATE:
Flashed the old tune back and everything works perfectly! Flashed a new tune with lower temps than the one that gave me issues and no problem. I don't the think temperarure setting was the problem. There may have been a glitch when I flashed the tune that gave me the problem in the first place.
Thank you all for the help and patience.
Jim

[gtstorey]

Are you writing calibration or entire?

[GMJim]

Are you writing calibration or entire?

I would assume entire? Just looked this up. Watched a lot of videos and read some HPT articles and didn't come accross that info.

[horsepowerguru427]

I would assume entire? Just looked this up. Watched a lot of videos and read some HPT articles and didn't come accross that info.

This is what hes talking about (refer to attached image)
,
When you use the "Write Vehicle" button at the top of VCM Editor, it brings up the little window that also allows you to use "high speed" along with "write entire" or several others. Some take longer than others, so i like to have a charger on the battery for a write entire...just in case...

[GMJim]

This is what hes talking about (refer to attached image)
,
When you use the "Write Vehicle" button at the top of VCM Editor, it brings up the little window that also allows you to use "high speed" along with "write entire" or several others. Some take longer than others, so i like to have a charger on the battery for a write entire...just in case...

Thanks for the info. While talking to HPT Tech support they told me "Writing as ENTIRE is needed for certain things to take." I really don't know the advantages or disadvantages of either?