The 1947 - Present Chevrolet & GMC Truck Message Board Network - Fan Switch wiring, wiring kits & fuse box panel?

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)

- Electrical (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=64)

- - Fan Switch wiring, wiring kits & fuse box panel? (https://67-72chevytrucks.com/vboard/showthread.php?t=731399)

Fan Switch wiring, wiring kits & fuse box panel?

Happy to say my cab wiring is on the floor next to me - trying to figure stuff out. Any input appreciated.

1. Fan Switch:

A. What is "LOOSE CONNECTOR"? - (See image below). I have a brown wire, but it's just a wire on a spade at the connector.

B. My temperature system isn't wired quite to factory diagram, including there isn't a pink wire (I believe it's pink) on the fan switch connector. Can you confirm (or other) the brown & pink wires are supposed to be on the same spade at the connector for the fan switch?

2. New Wiring Kit: At the moment I'm planning for an American Autowire or M&H kit. Crazy questions maybe...

A. Do these wiring kits come with a new fuse box? If so,

B. Is the back of the fuse box pre-wired? "Back" meaning the channel between the firewall block and fuse panel.

3. Fuse Box Panel:

A. From conversations it seems there's a provision to access the back of the fuse box. How is that done exactly? Wholly smokes what a cluster of wires......A bit frightening. :smoke:

B. Appears a sealant was used on the screw holes in the fuse box at the firewall. Any advice what that is?

Thank you...........

http://67-72chevytrucks.com/vboard/a...5&d=1487823705

Re: Fan Switch wiring, wiring kits & fuse box panel?

Anyone? If it helps, this is how my fan switch was wired. Everything worked fine, less this truck didn't have an anti-dieseling relay, and I can't remember when the A/C worked..........Thanks

Wiring: A six point connector using just four wires plugs into the fan switch. The following description is in order from the top down with the switch in a mounted position:

14 AWG yellow: Runs to the blower resistor. This wire is positioned on the front (TS) row of connector. NOTE: A second yellow wire is supposed to lead from the fan switch connector to the A/C switch connector.

18 AWG orange: Runs to the blower relay. This wire is positioned on the front (TS) row of the connector.

18ish (not sure) light blue: Runs to the blower resistor. This wire is positioned on the bottom center of the connector.

14 AWG brown: Runs down to the fuse box. This wire is positioned on the front (TS) row of the connector.

NOTE: Per the diagram the switch is supposed to have a pink wire that runs to the anti-dieseling relay. It may be connected with the brown. Pending

TS means truck side.

Re: Fan Switch wiring, wiring kits & fuse box panel?

..................

Quote:

Originally Posted by 71CHEVYSHORTBED402 (Post 7870712)

Happy to say my cab wiring is on the floor next to me - trying to figure stuff out. Any input appreciated.

I see you haven't gotten any replies yet so I'll chime in.

First off do you have AC on the truck or just a heater fan. I assumed you had AC because you asked me about the anti-dieseling relay the other day. So I posted the diagram you have.

1. Fan Switch:
Are you referring to the AC fan control?

A. What is "LOOSE CONNECTOR"? - (See image below). I have a brown wire, but it's just a wire on a spade at the connector.

This wire is the fan control switch wire on trucks without AC. It is the power wire to the heater fan control switch. I don't think it is used on the AC fan switch.

B. My temperature system isn't wired quite to factory diagram, including there isn't a pink wire (I believe it's pink) on the fan switch connector. Can you confirm (or other) the brown & pink wires are supposed to be on the same spade at the connector for the fan switch?

look at the switch control on the bottom terminal. I believe it is the pink wire for power to the control switch.If you trace it back up to the anti-dieseling relay you'll see that it is connected to the orange wire that is a jumper wire from the main fan high speed relay. The orange wire is the power feed wire from the fuse box (CIG) terminal.

2. New Wiring Kit: At the moment I'm planning for an American Autowire or M&H kit. Crazy questions maybe...

A. Do these wiring kits come with a new fuse box? If so,

Probably not unless you order it as a kit.

B. Is the back of the fuse box pre-wired? "Back" meaning the channel between the firewall block and fuse panel.

Again, You'd have to ask the vendor. It would have to be wired for your specific application.

3. Fuse Box Panel:

A. From conversations it seems there's a provision to access the back of the fuse box. How is that done exactly? Wholly smokes what a cluster of wires......A bit frightening. :smoke:

[COLOR="Magenta"]There's two screws that are diagonal from each corner of the box that have to be removed and you should be able to pull the fusebox away from the firewall a little bit.

Here's a picture showing the fuse box and the inner cab and outer cab connectors. The two legs on the fusebox are where the screws are located.

Attachment 1627630

B. Appears a sealant was used on the screw holes in the fuse box at the firewall. Any advice what that is? It's nasty stuff. LOL

Thank you...........

http://67-72chevytrucks.com/vboard/a...5&d=1487823705

Re: Fan Switch wiring, wiring kits & fuse box panel?

Ha....I like how you order responses. I put the original questions in bold, and responses in blue

First off do you have AC on the truck or just a heater fan...........Factory A/C...Difference is forward the Evap. box was pulled. That and I don't recall ever seeing an anti-dieseling relay. There's a provision for it both in dash and wiring.

1. Fan Switch: Are you referring to the AC fan control?.........Unless I'm off my rocker (quite possible), it's called CONTROL SWITCH on the diagram in the OP. Am I using the wrong term?

What is "LOOSE CONNECTOR"?.......... This wire is the fan control switch wire on trucks without AC. It is the power wire to the heater fan control switch. I don't think it is used on the AC fan switch. .........Very cool. Good to know I'm missing it on purpose.

B. My temperature system isn't wired quite to factory diagram, including there isn't a pink wire (I believe it's pink) on the fan switch connector. Can you confirm (or other) the brown & pink wires are supposed to be on the same spade at the connector for the fan switch?...........look at the switch control on the bottom terminal. I believe it is the pink wire for power to the control switch. If you trace it back up to the anti-dieseling relay you'll see that it is connected to the orange wire that is a jumper wire from the main fan high speed relay. The orange wire is the power feed wire from the fuse box (CIG) terminal..............Recall my system isn't wired to the diagram? You picked up on that in another thread. The anti-dieseling relay was wired per the info. at the bottom. What I'm asking is, where is the pink wire supposed to be placed on the connector for the fan switch? If it helps, my fan switch is wired per post #2.

2. New Wiring Kit: At the moment I'm planning for an American Autowire or M&H kit. Do these wiring kits come with a new fuse box?............ Probably not unless you order it as a kit......I am ordering it as a kit. I hear they even come pre-wired for HEI.....Perhaps for an internally regulated alternator as well

3. Fuse Box Panel: From conversations it seems there's a provision to access the back of the fuse box. How is that done exactly?..........There's two screws to be removed..............I understand. The fuse box and wires are sitting in my recliner.

Here's a picture showing the fuse box and the inner cab and outer cab connectors.............[Separating the back of the box has me stumped. That portion is shown in the illustration you provided, second illustration down and middle portion of the box. There is some sealant or glue on the bore for the screws where the box meets the firewall, if you get my meaning. Perhaps I'm babying it. That and I don't see any reason to open it, beings a new kit is pre-wired.

While I can copy and paste exactly how my system was wired less inside the fuse box, so you know where I'm coming from, I'm green how 12V operates. I appreciate all your help.

Me Anti-Dieseling wiring:

The wires on the connector are:
12 AWG orange: This wire comes from the blower relay.
12 AWG pink: This wire comes from IGN. UNFUSED
14 AWG dark green: This wire is connected to the A/C switch.

Re: Fan Switch wiring, wiring kits & fuse box panel?

Quote:

What I'm asking is, where is the pink wire supposed to be placed on the connector for the fan switch? If it helps, my fan switch is wired per post #2.

The pink wire is connected to the B terminal on the switch. It is the power wire to the switch which you can deduce by reading the legend to the right in the picture in the post above.

The power to the pink wire is provided by the jumper shown as the orange wire from the main high speed relay over to the anti-dieseling relay. It then goes to the B terminal on the control switch.

If you look at the legend and read the instructions, it says to get the different speeds connect B to L, M or H which refer to low medium and high fan speeds. It then tells which wires make the connections.

Re: Fan Switch wiring, wiring kits & fuse box panel?

Quote:

Originally Posted by VetteVet (Post 7874334)

If I understand this right, then the brown and pink go to the "B" terminal, correct? I hadn't noticed the letter codes on the fan switch, nor studied the grid. They're helpful thank you.

My switch was wired as:

Yellow to L terminal
Orange to H terminal
Light Blue to M terminal
Brown to B terminal

Re: Fan Switch wiring, wiring kits & fuse box panel?

Quote:

Originally Posted by 71CHEVYSHORTBED402 (Post 7874461)

I had a brain fart and forgot to include the image so here it is. It's been a hectic day.

Attachment 1628204

If you have the brown wire to your B terminal then you are getting power to the switch. I don't have AC on my truck so there may be variables in the years and models.

Re: Fan Switch wiring, wiring kits & fuse box panel?

Quote:

Originally Posted by VetteVet (Post 7874571)

I would say you're absolutely correct. For some level of confirmation, the fan control switch on my 72 A/C truck is wired exactly like my 71 A/C truck. At the switch anyway, I can't speak for the ends of each wire. In other terms, no sign of pink at the fan control switch...............................Like my 71 it has a 12 AWG Pink connected to IGN. UNFUSED. Where it goes from there I don't know, but if it's like my 71 it runs to the anti-dieseling relay. Appreciate another diagram and you helping to work through this.