Let me start off by saying I'm still using the stock and single fan that the TBI came equiped with for this 350 tpi swap I have done. The fan does not want to seem to work on its own. It only works if I manually jumper pins A to B on the ALDL. Any clues? Could I have maybe fudged the programming in the prom in tunercat or is it electrical related?

 

Unless you took the original wire (dk green/white) that went to the passenger side cylinder head fan switch and put it into GE8 on the ecm, it won't operate by itself through the ECM...

You can run that wire from the TBI setup to GE8 and the ECM will then control the fan. The stock TBI setup used a fan switch to control fan turn-on...

EDIT: this is for a 1227730 ECM.

 

How does jumping pins a and b on the aldl make the fan work? How does the ALDL tie into this?? Is this right?

 

oops...

 

I cant seem to find what ECM you are running. This will determine how you need to wire the fan. If all else fails though you could put a switch on the GRN/WHT wire.(run the switch to GND since that completes the circuit on most fans) Knowing the ECM YR/# would be helpful though.

 

Painless wiring MAF harness
1227165 ECM
Custom Prom

 

PS: I have definetely ruled the prom out. I checked the code.

 

Car is overheating. Need assistance...

 

Okay hopefully I can get a few problems eliminated, first is the relay good? Second if relay is good are you getting power to the relay, check the fuse (20A) that powers the relays, third check with test light that you are getting power from the orange wire and the tan/wht wire. Also check to see if the fan comes on if you turn the A/C on, this will tell you if the coolant temp sensor may be bad. Good Luck and dont give up.

 

Relay is good.
-I know this because jumpering a to b turns on fans which also means...
Fan Motor is good, relay control ground path(wire) is good.

I dont suspect sensor problems because they are all new. I'm going to burn a new chip right now and see if it was a corrupted flash.

 

In your earlier drawing you have the grn/wht wire connecting to ECM (E9) is this the connector and pin number? If that is the connector/pin number all my schematics show that to be connector C pin 1. I may be mistaken but that is what I found. Later!

 

Yeah, looks like C1 on the 1227165.. Here's a link to GMECM's FTP site with diagrams for 1227165 ecm.

ftp://ftp.diy-efi.org/pub/gmecm/manuals/1227165/

 

fan % duty
99.61
99.61
99.61
99.61
99.61
99.61
99.61

Iac steps
3

Fans (according to the code) are supposed to turn on around 200, so why will the ecm not send the information and power up the relay?

 

What program are you using to change the parameters on your chip? There should be some kind of option for temperature fan turn on or something of that nature.

 

 

Tunercat

 

I know this is not Tunercat, but it shows what I am talking about. Tunercat should have something along the same lines.

 

If entering Field Service Mode turns the fan on, your fan wiring is correct.

If your version of TunerCat also allows datalogging, connect ot the vehicle and read the CTS data while the engine warms up. The fan should turn on at or above your programmed value.

You might also want to check the A/C P/S flag in your programming.