[ehcees]

11/14/06
Here are ehcees replies in green to the latest respondents to the Resistor & Relay location? All of your input is greatly appreciated despite several contradictions between your answers as noted below. (What's a Mother to do?) Please state if your truck has factory AC or not in all replies. Were confusing each other by different setups for no AC & Factory AC. Thanks to all.
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4. dwaite72lnghrn Nice truck. I am confused by the post. Are you asking where each is?
4.1 Yes.
4. Resistor on an AC truck is in the top left of the heat box held in by 2 small hex head screws (It looks like 2 coils of wire), It has 1 plastic connector with 3 electrical connections (light blue, dark blue, yellow)

4.2 See #6 below for contradiction on resistor location.


4.3 Your correct on visual description of resistor compared to new resistor bought from Chevy dealer, GM P/N: 03929055, which has 3 spades or tabs to meet the connector. ehcees has removed glove box & does not see resistor on the top of heater/AC box. Please tell if the resistor is visible or further to the left of glove box hole & out of sight?

4. The Blower relay is a small metal can on the right side of the heat box behind the vacuum actuator on the passenger kick panel, it has 4 electrical contacts (small orange, dark blue, purple and heavy orange) + a ground (black wire).


4.4 On ehcees truck the relay is mounted on the right side of the heater box next to the vacuum actuator & kick panel, but not on the kick panel. There are two connectors attached to the relay: One has a single orange wire. Second connector has blue, another orange & purple wire. Total of four wires on two connectors. (See 2.1) ehcees does not see any BLK wire going to the relay as you state. Otherwise we agree on wire colors for relay.


5. Huck By far the most common problem with fan speeds on an A/C truck is the grounding of the relay. I would not fix anything before making sure that this relay has a good solid ground to the body.
5.1 Relay is attached to right side of heater/ac box by 2 small hex screws. Since box is plastic, ehcees assumes that one of the four relay wires must be a ground. See 4.1, above, for relay wire color controversy (BLK). Recall that the two lowest speeds do work & high-speed fan is dead. What does that tell you about grounding?
5. Very nice truck---you can download wiring diagrams so you can trace this design for yourself and save time--use as reference for future opportunities!! Do a search for wiring diagrams. You can also buy a copy of the factory shop manual for around $25. which will also help you with keeping this puppy running like new.


5.2 Electrical diagram or wiring guide on these trucks & old cars were often another book from the Shop Manual. If you can provide a specific web address for wiring & shop manual that would be welcome. Chilton 1988, 1970-1987 book is worthless on my relay/resistor question, but was good on many mechanical matters.


6. Andy4639 Resister is inside the air box inside the cab. if you take the screws out of the bottom box piece where the heater air blows out then take the next section off you will see it inside the box.


6.1 See #4 above for contradiction on resistor location. Who is right? Tell if your truck has factory AC or not?


7. roghedup72 are you saying that you don’t have a high speed on your fan?


7.1 Correct. No high-speed fan & two lower speeds work.
7. If so, I had a similar problem with a van I own. All the speeds would blow except high, after many hours of cursing and head scratching and replacing parts I found that all it was a bad connection for the main power wire going to the RELAY not the RESISTOR. It took several weeks of troubleshooting to find this out. And a lot of beer as well.

7.2 What color is the main power wire going to the Relay? Does your truck have factory AC or not?

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