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Hi All,
In an effort to diagnose why my heater blower does not work on any setting, I have traced the fault to the fuse box. Fuse is good but no power on either side. Looks like the feed TO that fuse is from the ignition switch but I'm struggling to find a decent wiring diagram of the wire colour and route into and out of the ignition switch to fuse board.
Anyone have a decent wiring diagram of ignition switch and fuse box for a 72?....and how difficult is it to get to the rear of the fuse box?
Last edited by Specialbrew; Sep 11, 2020 at 06:57 AM.
I cant provide a wire diagram.. but my 69 should be pretty similar.. but temper/qualify my info with that in mind.
Those top 3 fuses on the right of the fuse panel (heater, wiper radio ) are all fed by the same wire off the ignition switch in the ACC position. White connector on ignition switch Brownish colored 12 awg goes to fuse panel. All 3 fuses (heater,wiper, radio) fed by the right side of the fuses when looking from your picture.
The left side of the heater fuse goes to the black pyramid shaped connector on your heater switch and is the Brownish wire again but now 14 awg.
So if you dont have power on either side of the heater fuse but the wiper and radio still work then something is up behind the fuse panel itself.
Again mine is 69 but looks very similar to your 72
I tried to get pics sorry for the size but you can see the back of the fuse panel the 3 ACC items (heater wiper radio) are all connected/riveted to same buss from behind then another brown takes the power over to the pyramid shaped heater switch connector.
I cant provide a wire diagram.. but my 69 should be pretty similar.. but temper/qualify my info with that in mind.
Those top 3 fuses on the right of the fuse panel (heater, wiper radio ) are all fed by the same wire off the ignition switch in the ACC position. White connector on ignition switch Brownish colored 12 awg goes to fuse panel. All 3 fuses (heater,wiper, radio) fed by the right side of the fuses when looking from your picture.
The left side of the heater fuse goes to the black pyramid shaped connector on your heater switch and is the Brownish wire again but now 14 awg.
So if you dont have power on either side of the heater fuse but the wiper and radio still work then something is up behind the fuse panel itself.
Again mine is 69 but looks very similar to your 72
I tried to get pics sorry for the size but you can see the back of the fuse panel the 3 ACC items (heater wiper radio) are all connected/riveted to same buss from behind then another brown takes the power over to the pyramid shaped heater switch connector.
Back of 69 fuse panel Front of 69 fuse panel
Those photos are great. Just what I needed to see. I DO have power on the wiper and radio fuses so looks like I will have to pull the fuse box off to look. Do you know if it's just a case of unbolting it from the bulkhead to get access to rear?
Those photos are great. Just what I needed to see. I DO have power on the wiper and radio fuses so looks like I will have to pull the fuse box off to look. Do you know if it's just a case of unbolting it from the bulkhead to get access to rear?
Hello, I’m having the exact same problem in my 71, can you please share what was the problem with yours?
Yes, I found that when I separated the 2 half's of the fuse box, there was a trapped wire between them that was stripped and going to ground.
Thank you!! Mine seems to be a little different (71) as I have one dedicated orange wire for the heater fuse, I need to figure out why I’m not getting 12V
Thank you!! Mine seems to be a little different (71) as I have one dedicated orange wire for the heater fuse, I need to figure out why I’m not getting 12V
A bit late but... have you figured out what was the issue? Thank you
Yes, there was a wire trapped between the two halves of the fuse box that was grounding out.
Thanks! Do I need to remove the screw from the engine side in order to open the fuse box, or can I just open the two screws from the driver side to pull half? Also, on my 1970E non-AC, there is a dust labeled "HTR BW" (or something like that) -- do you know if that is the heater or is the only labeled AC HEATER? Thank you!
This is a wonderfully useful post. Youda thunk there'd be a website with this info nowadays, eh?
Originally Posted by mysixtynine
I cant provide a wire diagram.. but my 69 should be pretty similar.. but temper/qualify my info with that in mind.
Those top 3 fuses on the right of the fuse panel (heater, wiper radio ) are all fed by the same wire off the ignition switch in the ACC position. White connector on ignition switch Brownish colored 12 awg goes to fuse panel. All 3 fuses (heater,wiper, radio) fed by the right side of the fuses when looking from your picture.
The left side of the heater fuse goes to the black pyramid shaped connector on your heater switch and is the Brownish wire again but now 14 awg.
So if you dont have power on either side of the heater fuse but the wiper and radio still work then something is up behind the fuse panel itself.
Again mine is 69 but looks very similar to your 72
I tried to get pics sorry for the size but you can see the back of the fuse panel the 3 ACC items (heater wiper radio) are all connected/riveted to same buss from behind then another brown takes the power over to the pyramid shaped heater switch connector.
Thanks! Do I need to remove the screw from the engine side in order to open the fuse box, or can I just open the two screws from the driver side to pull half? Also, on my 1970E non-AC, there is a dust labeled "HTR BW" (or something like that) -- do you know if that is the heater or is the only labeled AC HEATER? Thank you!
I think I remember removing the screws from the engine compartment side. Quite easy access if you remove the grill on the left fender. Can't help you with the HTR BW issue sorry.
yuvalt
what do you mean " a dust labeled "HTR BW"?
what is a "dust"?
Originally Posted by yuvalt
Thanks! Do I need to remove the screw from the engine side in order to open the fuse box, or can I just open the two screws from the driver side to pull half? Also, on my 1970E non-AC, there is a dust labeled "HTR BW" (or something like that) -- do you know if that is the heater or is the only labeled AC HEATER? Thank you!
yuvalt
You do not state what year your vehicle is and your profile is not filled out but taking a wild *** guess I would suspect that is for the Heater (HTR) and for the Backup Lights (B/U)..... take a picture. I think these were normally 2 separate fuses but don't know your year either.
Thank you. I'll give more context -- Early 1970 without AC. my heater won't start. I do not see 12V on the brown wire that goes into the heater switch. I checked the top fuse (AC TCS SOL) and it has no voltage in accessory mode because I thought it was feeding the heater. But based on the conversation here, it could be that the fuse I need to check is the HTR B/U. I'm not sure if HTR B/U is connected to accessory because I could not find a diagram that matches this fuse box. Anyone has it by any change? What should I try to check next? If I want to see behind the fuses, I need to open the screw from the engine side and then the screws from inside? Also, what are the two connectors that are just hanging there? Thank you! (and sorry for hijacking this thread but it's about the same exact topic)
Update: I checked again, and there is 12V from the brown wire of the switch. I'm confused now and will need to check everything again, since I was dead sure there was no 12V the fuse is the problem. Back to checking everything....
Fuse box/ ignition switch wiring
