csmoore88

It may well be the steering lock module but the colors do not match those described in your post for the blower motor relay. It does not have an orange wire coming out of it.

I have stared at that schematic so long it is making sense. If there is power at the resistor then that relay has to be good right? I mean, we have determined that the power is coming from fuses 18/51 and the relay looks like it relays that power and grounds to g202. I am hoping the actual control unit is not bad b/c that means pulling it and sending it in for repair. It is no longer available from GM. Yuck!

I am at a loss. I haven't the time, because I am a hostage at work, or the knowledge / experience, or the patience for this. I just need to live with the fact that i have 2 50 air. 2 windows down 50 miles per hour. and who wants to drive a vette in the winter?

csmoore88

I will, sorry for my frustrated rant.

Fun Fact!!! I am tinkering with the headlight and bump the left front chassis ground in the engine bay and "ding, ding, ding'.....turns out I DO have a door open dinger ha ha. I checked that ground the other day when I noticed it had been chopped off and ran direct to the post. I guess the wires are not as tight in the copper bracket as I thought. Give it a jiggle and ding.....ding.....ding. ha ha ha ha ha ha ha ha ha ha

Trios

Ah. He specifically stated that he had determined it to be the "high speed fan control relay" and NOT the blower motor relay. The high speed fan control relay is shown in Bill's diagram as being inside the 'Fan Control Processor' but I don't know if the 'fan control processor' is really a discrete piece of equipment or a term that GM is using to name the combination of the high speed relay and resistor.

The high speed fan control relay, if it is its own piece of equipment, should have orange, red, black, and purple wires.

dadaroo

I have worked from Moscow Russia (really, amazed me) to Australia and almost everywhere in between on C5 issues. It has helped to use Skype for a face to face discussion on problem solving. I would recommend you sign up in case you need to use it. It's also FREE.

Mr. Sam

Munckhof

It seems so.



If I read Bill's wiring diagram correctly, the high speed fan control relay is supposed to be inside the blower motor control processor. However Cody mentions it sitting loose behind the BCM, apparently outside the blower motor control processor.

That relay box isn't just responsible for the 'high' setting of the blower, it also facilitates the other blower speed options. At 'high' setting, the coil in the relay will pull a switch so that current flows directly from the fuse block to the blower motor, through the red wire. At any other setting, the coil isn't energized and the current flows through one or more of the resistors in the blower motor control processor. Summarized, the relay box is always in use when the blower is not in 'off' position.

Apparently in the past someone has pulled that relay box out of the blower motor control processor. Probably not because it was working fine. I reckon you're not the first to try to tackle this problem.

And apparently someone found it necessary to replace some wires, because:

and I recall having read somewhere in this thread that Cody also found some other wires to have unexpected coloring. The original wires were probably damaged somehow.

Regarding your processors, perhaps both of them are bad...

Cody,

1. Where did you get the 'new' blower motor control processor? Was it a spare part, an 'extra' to the car when you bought it? And what did the previous owner tell you about it? Did he reckon it'd be okay? Considering the fact that someone apparently already did some work on it, it could be that this new processor wasn't the answer the previous owner or his mechanic was looking for.
2. I assume that this uninstalled processor still has its 'high speed' relay inside?
3. Have you performed tests on both 'old' and 'new' relays?
4. Have you also checked the diameter of the new wires? Does it have size 2 as specified in the wiring diagram?

csmoore88

I discovered the high speed fan control relay by searching for HVAC parts on Amazon looking for this specific component. It doesn't look like it was ever part of any other part and has its own individual part number from GM. Maybe I am just crazy(i.e. stupid) but it is not a part I would expect to have been pulled from any other component. Thoughts guys?

I apologize to all of the interested parties and those who have offered to help. I truly do work 11-15 hours a day and, other than Sunday, I really have NO time for my car. It is ripping me apart at a molecular level because I have made (we have made) such progress that ALL I WANT IN THE WORLD is to bring this thing home and fix the last obstacle. But the fact remains that I leave at 5:45-6 a.m. and do not return home until 8:30 ++++. I hope no one thinks I gave up. I am just waiting for Sunday when I can attack it again.

I trusted the dealership to put my headlight gear in b/c I was covered up with work. $150!!!!!!!!!! just for a brass gear replacent. Well, they will not do another repair on my C5. I am on my own in a town that I just moved to and know not a soul. Corvette forum has saved my @$$ and I value you all!!!

Munckhof

Again if I'm reading the wiring scheme correctly, the blower motor control processor (let's just call it BMCP) should contain two parts: 1) the combined four resistors for the low and medium speed settings; and 2) the relay box for the high vs. 'other' speed settings. In the wiring diagram, boxes 1) and 2) are within the BMCP's box.

The relay having its individual part number makes sense because it's a separate part within the BMCP. In case of a failing relay, GM mechanics would (perhaps more cheaply) replace that relay rather than the whole BMCP.

Patience is a good thing to have when exercising this hobby. Once this is fixed you'll see something else that's either to be repaired or 'improvable'. If there's nothing left you'll think of things to do. Or you'll give the car a nice polish.

As long as the car runs that's great. The more functions that work, the more bonus

I think nobody around here will ever think you gave up! Moreover, I don't think you're going to give up this car at any point and that you'll drive your dream for thousands of miles to come.

Trios

I'm not sure that the 'blower motor control processor' is a discrete piece of equipment in this schematic. I think it may be a term that GM is using to refer to the resistor block and the relay as a unit, but that the components are separate.

The only justification I have for this is that usually on these schematics, a single piece of equipment is indicated by a dashed line. See above at the fuse block, the 'HVAC Control Module,' the ground splice pack, etc. Those are all individual components and they all have dashed lines.

The BMCP is a solid line, and it certainly seems that at least in Cody's case, the parts are separate from each other. Hopefully Cody can get us a good picture of the relay and the broken wires at some point so we can see what's what.

dadaroo

The FSM shows the Processor has a single connector with 7 pins that match ALL the inputs. It should also have a Purple and Black pigtail out of it with a connector for the motor. That is all.

Therefore, based on the FSM, the processor high speed relay is INSIDE the Processor with the resistor, not external.

Figuring out why the bower motor does not run should a few minutes job. This is as simple a circuit as you can find in the C5. I wish I was closer I would just come over and do it.

OP, I would be glad to walk you through the diagnostics over the phone. You have my number and I have yours.

I can tell you exactly where to put the Red probe and where to put the Black probe.

There should be only about 6 individual checks to figure out where the problem is.

As I understand there has yet to be a test to see if the motor is good. A simple resistance check might just show it is bad (open circuit in the motor).

dadaroo

Thanks Chuck, good input. I will focus on that. It should be easy to find out where the voltage is dropping. We need to get full battery voltage to the motor connector Purple wire for high speed and then we'll worry about if the motor is bad.

I left him a message earlier to tell him I was available any time he was.

When you two did that was he testing voltage at the Purple wire using the Black wire at the connector as his ground or a separate known ground point?

csmoore88

I checked the red(purple oem) wire with the black probe on the ground bolt at g202. No dice. I am eagerly waiting for tomorrow. I am confident we will get it sorted then. Thanks!!!

csmoore88

Hello everyone, I apologize for falling off the world for a little bit. I had another manager on vacation and had to do his job AND mine. This resulted in several 14-15 hour days and no days off.

I still have no answer for the hvac situation. I have checked and re checked the connections and voltage to and from the resistor. I even replaced the blower motor (early, early, one morning) and still no luck.

Tomorrow I WILL have my day off. I am replacing the stock shifter so I will have the center console removed. If anyone knows of anything I will need to check while I have access please let me know. I will check back either today / tonight after work or in the morning when I get started.

Thanks again everyone who has helped me. Chuck, I pm'd you back the other day, thanks for your concern bud.

voda1

csmoore88

112° heat index today then rain. Damn Alabama summer!!!!! I will be back soon I promise. Today is my day off and I only worked 3.25 hours but the heat is unbearable. I appreciate everyone and hope you can be patient with me. I got my headers and exhaust to be installed and tuned on the 15th next month. The forum lead me to a dyno tuner in north Alabama and I think it will work great!!. Hopefully by then I will have a/c to drive the 2 hours to his garage. Thanks again tho all who have helped!!!!!!!!!!! Maybe soon we will talk about this in past tense while I have my car up to snuff against all expectations. Thanks again and again and again for all of your efforts, please don't give up on me this close to the finish. Have a great night and I Weill keep you all posted.