2003 Tahoe crank no start HELP!!!

[65oldsboy]

I have owned an '03 Chevy Tahoe for about 2 years. Never had a problen until a few weeks ago when the a/c blower motor would just run on high and not on positions 1-4. Easy fix: It must be the resistor. I checked it wth a test light and confirmed my diagnosis. Put in a new resistor today and the a/c works fine buuuuut now the truck won't start!!!???? There should be absolutely no correlation between the blower motor resistor and no fuel pressure. I don't get it. Cranks fine but now no fuel pressure at all. Replaced fuel pump relay and all fuses in the fuel pump circuit. I can't get to the connector at the fuel pump without dropping the gas tank. Too much of a PITA without a lift. It figures that I just filled her up. I have a subscription to Alldata but I don't have the $5000 scan tool I am expected to use. Anybody got any suggestions before I call in the tow truck?

[Montreux_Blue]

The a/c switch was a recall item, it was a connector that would short across. It only took about 45 minutes for the dealership to fix it for free.

[65oldsboy]

The a/c switch? The one on the dash? That seems to work fine.

[65oldsboy]

I just checked Alldata. No recalls on the a/c switch.

I forgot to say there were no codes in the computer.

[Montreux_Blue]

I meant the blower, sorry, been awhile. It was a connector under the dash that went to the fan motor. It's located on the passenger side just to the left of the fan motor. Mine started by losing fan speed 5, then 4 and 3, had to get my helper to kick it every once in awhile to get it to work. Then found out it was recalled and had it fixed. It was a 2003 Silverado.

[65oldsboy]

The a/c is working fine now. I just can't start the truck because there is no fuel pressure. I'm just not sure how the repair on the a/c could relate to the fuel pump not working...unless cycling the ignition (it energizes the fuel pump) on and off 6-8 times blew out the fuel pump. If that is the case, then the fuel pump was ready to die anyway. I'm going to give it one final crack tonight. If I can't get it started, I will throw in the towel and admit defeat. If I had a lift in my garage, I'm sure I would be able to do it myself. It just bugs me that I think I am able to fix it but just do not have all of the tools/equipment to do so.

[wa407mpp]

key

Does your truck have a transponder anti-theft system? If so, it may have somehow lost the key codes and needs reprogramming. Also check the fuses sometimes the manufactures tie accessories into other systems to save manufacturing cost.

[65oldsboy]

No anti-theft system. I have replaced all fuses in the circuit (from the wiring diagram) and replaced the fuel pump relay.

[randy]

A shot in the dark, but have you tried clearing the computer? There is one CPU fuse in the panel, don't know if it's under the hood or inside on the Tahoe. Disconnecting the battery and then pulling the CPU fuse will clear any stored codes and possible hang-ups in the CPU. JAT, and easy to do.

[65oldsboy]

I have a cheap scan tool. There are no current or history codes in the computer.

[randy]

i don't know the capabilities of a 'cheap' scan tool, but i do know that the fuse trick completely clears the codes.

[cywelchjr]

No anti-theft system. I have replaced all fuses in the circuit (from the wiring diagram) and replaced the fuel pump relay.

My 2003 Malibu just had the fuel pump go out and it acted like you describe. One minute it worked, then next no fuel pressure at all.

[65oldsboy]

i don't know the capabilities of a 'cheap' scan tool, but i do know that the fuse trick completely clears the codes.

It's worth a shot at it. It won't take more than a few minutes. Thanks for the tip.


THe cheap scan tool reads and clears codes and gives a little bit of streaming data like sensor readings and such. Nothing like the big dollar machines in professional repair shops but it has helped me before.

[randy]

BTW, there is an intermediate scan tool available from scantool.net. I have it on my laptop, works for any OBDII system and a few other systems are available. Gives me something like 75 different readings in real time. Last time I used it it saved me a few hundred (including shop diagnostic time) on an O2 sensor, the scantool told me my trouble was the downstream sensor.

The scantool interface cost less than $150, software is free.

[foreda]

Relay

Did you try another relay? May have a bad set of contacts. Also may want to see if circuit to pump is drawing any current. How about grounding??