if the negative cable touched the frame then ground touched ground, no problem. If a positive red cable touched the frame then the vehicle sourcing that power temporarily shot hundreds of amps through that cable. Then when that cable came off the system experienced a load dump event which causes the voltage to spike throughout the entire sourcing vehicle. Same list of potential trouble as I gave before.
Right. I've only noticed one fuse blown. Injectors, maybe. I don't know if that's lucky or means there's problems fuses didn't stop. Checking this will be a priority in daylight.
The only saving Grace is that I didn't do this. The guy wanting to buy it did.
Wonky electrical problems are like a treasure hunt without the map. It's my favorite type of problem to solve, but this opinion is not universally held. LOL
Here is the schematic ( \/ \/ CLICK \/ \/ ): Manual HVAC Blower Motor Schematic
From your symptoms, we know that the wiring to/from pins 87A & 30 on the blower motor relay are working fine. What we do not know is if there is a proper ground to the switching coil (pin 85), switching signal power (pin 86) and then the input power on pin 87 that comes from the HVAC fuse in the underhood fuse box (which is not to be confused with the HVAC fuse in the instrument panel fuse box that powers the fan through the blower motor resistor).
BTW, I would only keep that Chilton's manual around if you need a wheel chock or table leg shim. That's about all they are good for. They are way too generic in terms of information to be helpful. I like AllDataDIY.com for the money; 5yr subscription is $50 for the first vehicle, $35 for each additional vehicle.
Could i get this schematic in a larger format for printing? please?
Don't ask me why, but for some reason imbedded/thumbnailed images like that got real stupid on one of the forum software upgrades.
Been having issues again. On 4 it would stop for 30 40 seconds and start up. 1 2 and 3 worked fine. I could wiggle the relay and 4 would kick on and off, so I went to replace the pigtail and saw I had 3 pins burnt so I replaced the relay, too. Now I cant get 4 to work, but 1 2 and 3 will.
Do you have all of the faulty wiring and socket replaced and cleaned up and still have the problem? Have you continuity checked everything? You might want to read my article on wiring faults in my signature.
I replaced both the pigtail and the relay. I just went through to make sure the wiring was correct. I wont have time to really get into it until thursday or the weekend.
It's a learning experience for me and the schematic. I must not understand it yet, because it seems that visually comparing the relay to the diagram, 85 and 86 look like they are reversed.
Relay has 85, 87 and 87a on one side.
Diagram appears to have 86, 87 and 87a on the same side.
12-09-2019, 08:28 PM
