454 EGR air pump question and Aux Cooling fan issue

[Metrodps]

OK so the Crew cab had the Air pump removed and tubes with the exhaust holes plugged. Looking at wiring it shows two connectors one for each Left and right air divert solenoids . I am not good at reading wiring stuff. Does any one know what all would of come off the air stuff and what might of been plugged in to carb?

I'll try to take a picture of what I am looking at but have already found the hot wire to aux cooling fan relay cut. The aux cooling fan switch on pass head has juice to it. Not sure if it should. the yellow is hot and the squiggly is wire that was cut. I check fuses and the wires to fan no juice the relay I could not get un hooked. Not hacked as bad as some trucks I've seen but still need to see what is what.

 

[dyeager535]

Aux. fan cooling sw. is the ground for the circuit. When that switch closes (whatever temp it was spec'd at) the relay should allow power to the fan. Any time you see that grouping of lines in a triangular shape (like at the switch, or "sheet metal ground") you are looking at a ground. The diagram indicates the switch is normally open (NO, vs normally closed, NC), so that switch creates a path to ground when it gets to the right temp.

Circuit 935 is probably ignition switched power, but it may be battery...in some apps GM powered the fans even with the engine off.

Circuit 2 is battery voltage (constant) so when the relay closes (caused by the temp switch grounding) you'll see voltage on 702, which is the fan +. If you put 12V to 702, assuming other wiring is correct, aux. fan should run. If circuit 2 wasn't cut, you could unplug relay, and jumper 2 and 702 on the relay connector and power the fan as well.

AIR, not going to be a huge help. But as I remember AIR, with solenoids, I can't see why anything would be hooked up to the carb. Maybe the air cleaner. Do you have access to the emissions manual for this year? Might help. Not sure if it's at the link in my signature block, but worth checking if you haven't.

 

[82355]

As the truck did not meet emissions standards, I wonder if they have the emissions for it in the book?

Martin

 

[dyeager535]

As the truck did not meet emissions standards, I wonder if they have the emissions for it in the book?

Martin

It's got AIR, so they've got to have something that talks about it's operation. Or so I would think. It could be like vacuum hose routing I suppose, if your core support sticker is gone, you are SOL.

 

[Metrodps]

It's got AIR, so they've got to have something that talks about it's operation. Or so I would think. It could be like vacuum hose routing I suppose, if your core support sticker is gone, you are SOL.

First evap is on radiator the second is on the air cleaner box. It has the vacuum diagram on the part you can't see. I'll get pictures of the motor today when I get back from taxi duty and trying to get the title and plates.

 

[frankin5]

need to see what is on the far right of the last picture, that is the vacuum line routing.

 

[dyeager535]

Two EVAP cannisters with a carb? Lovely. That's gotta be a mess. At least for a HD emissions rig, which generally were pretty basic.

 

[Metrodps]

need to see what is on the far right of the last picture, that is the vacuum line routing.

 

[Metrodps]

OK I figured out some of the wiring after getting plates which I leave for another Ranting post in the lounge.... Back to the yellow fellow; the two wires that are taped (green tape ) are from the AIR diverter valve (33) and the area on the fire wall where the two brackets are that normally is the fuel pump relay are Check engine Lamp relay (100) and the missing one on yeller is the AIR Diverter module (99). I didn't climb in to the motor area today because my leg was hurting pretty bad but if I feel better I pull the air cleaner off and do some more figuring of things.

So on to the aux cooling fan. Fan direct off battery works. (thinking on a accessory powered switch below dash) Wondering if the sensor switch on block should show it has power when I put test to it. The wire from the Junction box is cut going to the relay. So I am kind of afraid to hook it back up for fear of a fire.

First picture is the check engine relay the second is the Aux Cooling fan relay the red wire is wrapped up by it. The third picture is the aux cooling temp sensor with one wire the green that shows as being hot. I ground my light and touch the wire end and it lights as hot. The fourth picture shows one of the diverter wires. The others are from the service book.

 

[dyeager535]

With a multimeter set on continuity, test the terminal on the switch for continuity to ground. If working right, the switch will NOT have continuity to ground (open) with a cold/cool engine. When the engine is hot, the switch should have continuity with ground (closed). I'd assume the switch works for now, but if you have the patience, you can test that it closes properly. Without knowing closing temp though, you might be there awhile.

Check the fuse panel side of the cut wire for 12V with engine off, then key on/engine off. That will tell you if it's switched or not. If it doesn't have power at all, check the fuses. Can't quite make out in the wiring diagram, but if you look at the pages of the manual devoted to the fuse panel, you can tell if it's ignition switched or not...but may just be easier to test the wire itself.

Pretty unlikely to have a fire if you know what circuit you are dealing with, and have used a multi-meter/testing device to ensure power/no power, etc.

Check for continuity on the relay terminals that correspond with circuits 2 and 702 if you want to make sure it's open as it should be. Not sure they ever fail closed, but anything is possible I assume.

If the fuse panel relay feed seems to work properly, and the switch works properly, you should be ok hooking it up. When that portion of the relay is hooked up, if the key needs to be in run to see voltage on the fuse panel relay feed, put the ignition in run. Verify voltage at that terminal on the relay. Now ground the temperature switch wire to the head. Check continuity across the same pins for circuit 2 and 702. There should now be continuity. If there is, the entire circuit is working correctly. You can remove the temp switch wire from ground, and there should again be no continuity on 2 and 702.

And yes, that emissions sticker is a disaster. That's as bad as the CCC cars and trucks.

 

[Metrodps]

Figured the yellow truck stuff out and fixed the wires that were disconnected for emissions correctly. Got the wires tied back in group (loom just crumbles from heat). I traced the wiring for AUX and checked things besides the power was cut by radio service when they took the two way out. Fan works hot from battery, and I can remove relay and use a jumper and works hot or with key. So a $15 relay fixes that.

Wondering what this was for I don't remember it on the Motorola Two-ways?