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It seems that it's time to replace the blower resistor on my 67 Toro. I can't find an exact match online, but I find many that are close. If I change the wire ends from a cluster connector to singles, couldn't I use the newer version of the resistor as long as I got the wiring positions correct using measured resistance? Has anyone done this so I don't have to reinvent the wheel? Honestly, it seems the biggest hurdle is finding the correct base plate shape and size.
I don't have 67 diagram in front of me, but yes, if you can draw up a schematic of this resistor pack and put the wires in the right positions you should be all set. Do they show a photo of resistor side of that one you found online?
I can detect power going in, but no power going out to the blower motor. Direct connecting the blower motor shows it runs fine. But operating the switch on the dash does nothing at all. There are only two little screws holding it in - I can pop it out later and confirm. I was also thinking to myself that with a replacement piece I could technically just repair the old switch and not have to worry about the wire connection at all. These things are pretty simple in construction.
I don't have 67 diagram in front of me, but yes, if you can draw up a schematic of this resistor pack and put the wires in the right positions you should be all set. Do they show a photo of resistor side of that one you found online?
There are dozens of these online that show resistor coils on the back side in very similar configurations as original. It wouldn't take much to determine which post gave which amount of resistance to determine what wire went where.
Just following along - mostly because I just replaced the blower motor resistor on my 2003 Ford F-250. I see what you have from only one side. I'm betting the opposite side is going to look like it was toasted in a toaster oven. Mine has four terminals. I didn't need to test for resistance for each post, but following your logic you should easily be able to determine position/resistance. Good Luck, I think you're trending in the right direction.
I got one of the it will fit deals from the parts depot. It fit the hole In the housing and the screws holes were correct. Backed the fitting s out of the original holder and used a ohm meter and a wiring diagram. It only took 5 mins once you figured out which resistance per terminal.
Pulled the resistor and it didn’t look bad. I cleaned the connectors and applied dielectric grease, then reinstalled after confirming there was a (slight) difference in ohm resistance between the terminals in and out. I measured 2.66, 2.65, 2.64 ohms. I was surprised it was that close.
I then hit the power switch and was met with a loud clicking of the new relay on the fender. I confirmed power in at the purple wire on the relay double connector, and power out at the purple wire going to the blower - but no blower fan when hooked up. I measured 10V power in and 9V power out with the car not running. Again, hooking 12V power directly to the blower makes it work fine. Am I looking at a bad relay? After the other fender relay (also new) was bad, I’m ready to take this one apart as well… I believe I have the wiring correct:
I measured 2.66, 2.65, 2.64 ohms. I was surprised it was that close.
I'm suspicious of those numbers. I would expect a minimum of at least a difference of 1.0 Ohm between any two terminals. Without a spec sheet, tough to say what the minimum resistance should be between terminals; but, a difference of 0.01 Ohm isn't providing any difference in resistance, IMO. I'm suspicious the resistor is bad.
I'm suspicious of those numbers. I would expect a minimum of at least a difference of 1.0 Ohm between any two terminals. Without a spec sheet, tough to say what the minimum resistance should be between terminals; but, a difference of 0.01 Ohm isn't providing any difference in resistance, IMO. I'm suspicious the resistor is bad.
I also note that the power going to the fender relay from the resistor is only 10V - but it DOES make the relay click loudly when the switch is turned to HI. I'm looking online for USA made pieces just in case we are looking at a case of Chinesium components on the relay. I'm pretty sure I can source a new resistor locally and check resistance on it for a comparison. Chasing these gremlins is exhausting. I need to be tearing down the motor for the re-gasket job it needs. Oh, well - I have all winter...
Generally, (I think) many resistors fail on the lower end of the resistance circuitry (i.e. low speeds) but work on full speed - generally (I think). Anyways, have you examined this diagram. I'm not certain it is directly applicable to your vehicle, but it's worth a read. If I'm not mistaken, the actual wiring diagram is included in the back section of the CSM (maybe)? Here's the diagram from the post below (see Post #2):
Generally, (I think) many resistors fail on the lower end of the resistance circuitry (i.e. low speeds) but work on full speed - generally (I think). Anyways, have you examined this diagram. I'm not certain it is directly applicable to your vehicle, but it's worth a read. If I'm not mistaken, the actual wiring diagram is included in the back section of the CSM (maybe)? Here's the diagram from the post below (see Post #2):
Thanks, Norm, and yes - other than the relatively close resistance readings on the resistor, I think fingers point to the relay. Keep in mind I have NO fan even on HI, just a click from the relay. I haven't found anything that says what resistance levels are supposed to be, other than "different". It seems that no matter the resistance level, the power going through the resistor to the relay and then to the blower motor should be enough to run the fan. Something isn't right here....
Bob - Have you reviewed that URL link I provided? Is there a wiring diagram in the back of the CSM for the blower motor assembly - it's mostly contained in the A/C section of the CSM manual. If there is a direct correspondence in the diagram I posted and your '67 Toronado, I'll point out something glaring to me at least. The purple power wire should go directly from the blower relay to the blower motor. That would make sense as the Hi speed receives no resistance; however, I see two purple wires on your relay and I see a purple wire feeding into the resistor? Double-check the wiring itself which may be the issue?
EDIT: I think you should have blower motor fan on High if wired correctly since the purple wire doesn't travel through the resistor? IOW, the purple wire goes directly from relay to blower motor with no resistance.
Disassembling the old relay and comparing it to the schematic, the right side top wire should be the black/orange to the 30A fuse, and it is. The bottom right should be a blue wire going to the resistor - mine is purple. The center should be a purple wire going to the blower, and it is. The far left should be black/orange going to the blower speed switch, and it is. This old relay doesn’t really appear to be bad, though it only clicked like my new relay does. Two bad relays? I can’t think of anything left to check.
I feel for you. I don't like those last two diagrams you posted since they don't show any wire colors. There's no wiring diagrams illustration in the AC section like the diagram/chart in Post #12, eh? That's really too bad.
I (obviously) don't know how your car is wired and I don't know how that resistor is wired, but in reference to your statement:
You're right in that a wire should be direct from the resistor to the blower.
I actually stated the wire should be direct from the RELAY to the blower:
IOW, the purple wire goes directly from relay to blower motor with no resistance.
If you think about this, I don't believe there's any reason for the HIGH speed wire to go from the relay through the resistor since you don't want to impede (create resistance) of the HIGH speed wire. The purpose of the resistor is to reduce blower motor speed by creating resistance so as to lower the blower motor speed. There shouldn't be (IMO) any need to create resistance in the HIGH speed blower motor feed. I mean, it could certainly be the resistor is doing nothing more than shuttling the HIGH speed side, but I'd think that is highly unnecessary. End of the day though the wiring diagrams you posted are really bad if they don't show any wire colors.
I feel for you. I don't like those last two diagrams you posted since they don't show any wire colors. There's no wiring diagrams illustration in the AC section like the diagram/chart in Post #12, eh?
Post #12 is super close to what I have, and I found a couple other threads referencing these relays in the Cutlass, which have the blue wire feed - that's about the only difference. I used the schematic from #12 to compare to my relay pic above. Post 15 shows what I have from the CSM color wiring chart - not even close. The other pages I lifted from the CSM and ASM, and yeah, no color or even a clean drawing of the wires and their start/stop points.
I really believe I have the wiring correct. I get a hard CLICK from the relay when I switch to HI on the dash. Since all these wires run through the relay after the resistor, it's either the resistor giving too much resistance, or the new and old relays are both bad. Since we both have doubts on the resistance levels of the resistor, I'm going to buy a new one and see if that makes a difference. The relays are cheap as well, and I may buy a second new one as well. But I can't see anything else to try here.
I don't want to muddy the water, but I'll simply throw this out there in terms of resistance. NOTE: This diagram blow-up is from the 1968 A-Body wiring diagram (about the closest I could get to any 1967 in my repertoire). What is of interest, Oldsmobile selected to either list the resistance (ohms) or not list the resistance (ohms) in select years and in select models regarding the resistor. None-the-less, the wiring color diagram does match what you provided from your 1967 manual (Orange, Blue, Yellow) but that's about where it ends. With that said, it does list the resistance (ohms) which is interesting. As I mentioned earlier, I suspect the resistance you measured is not consistent with a working resistor. The resistance displayed here (this diagram blowup) makes sense to me (at least it's a stated resistance even if only for the A-Body). I "suspect" the resistor is bad as we're both suggesting; although, the wire colors are confusing especially the routing of the BLUE wire & the PURPLE wire(s). I believe it reads 1.97 ohms (LO), 0.87 ohms (MED) and no resistance (HI).
It's nice to see the actual numbers - the more I see these resistors, the more they look the same. I note that my old one has an actual resistor as well as the coiled wires for resistance - but as I look at a number of replacement parts, they just use what seems to be a 14-16g copper wire bent into the same location. I wonder if I could try that. Now is when we need Radio Shack back!!
Last edited by BSiegPaint; November 22nd, 2023 at 01:52 PM.
Well, you should at least get the HIGH blower speed when connected "IF" the resistor was actually "WORKING" since you'd be bypassing ANY resistance created/assembled in the resistor. Since I believe you said you get no blower speeds at all w/ the resistor in place in the circuit, I'm suspicious there's a bad solder weld/corrosion/broken/short-to-ground in that resistor. It would APPEAR you're getting voltage to the relay if you can hear the relay click.
The relay is a simple coil around a magnet which pulls the center contact (purple) to either one contact or the other. It is called single pole, double throw (SPDT)
We'll most likely find out if you replace the resistor, eh?
Mine runs on HI with the resistor completely disconnected. Just went out there and tried it. No need to worry about the resistor until HI works.
I'm curious if there's a difference in the type of resistor and the wiring of the blower motor, resistor & relay between 1966 & 1967 Toronados. I've noted along the years there have been some differences in wiring of the blower motor circuit in various A, B, C & E series. Outside of this discussion, but on my 2003 F-250 the HI speed is not even routed through the resistor & I suspect this to be the case on other vehicles. Apparently, the HI speed is wired through the resistor (based upon the wiring diagram) on this 1967.
Again based on diagram in post 12, when not on the HI position, the relay switches to the normally closed contact which routes power so that lower speeds work. Interestingly, HI powers the blower through a different fuse than the other speeds.
On HI position (on the post #12 diagram), the switch fires the relay to remove the switch from the circuit.
Understand, and a very valid point. However, we're not 100% the diagram in Post #12 is directly applicable to a 1966 1967 Toronado, unfortunately. There exists some disparity in wire routing & wire color.
Last edited by Vintage Chief; November 22nd, 2023 at 02:26 PM.
Reason: Edited year from 1966 to 1967
Was that a typo? His is a 67, correct. Is the diagram in post 12 not for 67? Just making sure I know what's what since I just barged in here
On my 66 there are two purple wires at one end of the resistor. This is because the fan speed switch always carries blower current rather than having the relay which I guess was introduced in 67.
Last edited by mike 66 toro; November 22nd, 2023 at 02:24 PM.
That "is" the issue. You should probably read the posts in more detail. I provided Post #12 diagram and the URL link I obtained it from. You have a 1966 the OP has a 1967. Again though, not certain the OP's '67 is wired the same as the diagram in Post #12 & what the OP (Bob) provided from his CSM doesn't jive with wire color. Thanks again for any input.
I think it's safe to say none of the colorized diagrams are right. For one thing, we have three resistors, not 2 as suggested by the diagram. Also, it seems I have a relay for HI after all, on my 66. I'm tracing things now just to confirm where it is exactly. I think they did a lot of on the fly changes on these!
On my 66 there are two purple wires at one end of the resistor.
The notion you have two purple wires is far closer than we've seen on any wiring diagram, thus far. Bob has two purple wires on the RELAY and one purple wire on the RESISTOR (from what can be seen in the images).
Originally Posted by mike 66 toro
I think they did a lot of on the fly changes on these!
Here's exactly how mine's wired. Looks just like post 12 except for the routing of the second purple which could have gone straight to the relay instead of all the way to the resistor and back. Two purple wire on RELAY would make a lot more sense, which is what bob has. it's almost like gm got a little smarter as time passed. Based on Bobs photo, his uses the double-throw relay like in post 12. Mine has a single throw. Again, evolving design.
(I went out there just now to figure out why only HI was working, solved - loose wire)
Mine (66)
Here's why they changed this: Two thick purple wires crimped poorly into one crimp is a no-no. All of the current running the HI blower passes through that joint and gets you this result regardless what fan speed it's on. I'll be fixing this...:
Last edited by mike 66 toro; November 22nd, 2023 at 03:27 PM.
Mike - Great info & excellent diagram(s). Yes, some type of evolving wiring occurred which wasn't documented and what was documented was poorly documented during this time period. And, as I suggested in earlier posts, and tried to review in the diagram in Post #12, there exists serious disparity of the wire colors and routing.
Back to the supposed issue at hand. Note in Post #9 & Post #10 the resistance readings Bob obtained. Those are not good resistance readings. No reason to suspect Bob measured the resistance (ohms) incorrectly (as long as the resistor was isolated with no other wires attached). There should exist a difference of at least 1 ohm between any two of those terminals, IMO. Albeit, I believe his resistor is toast. Thoughts?
EDIT: Examine Post #21, as well which demonstrates ohm readings.
Last edited by Vintage Chief; November 22nd, 2023 at 03:44 PM.
Well there should be three resistors, since we have three not-high speeds, for 4 total (unless bobs dial only has three speeds?).
In Bob's photo, I see two resistors and an overheat protection device.
So assuming Bob has four speeds like mine, then his speeds through the resistor module he showed are: 1) HI: relay kicks in and bypasses the switch and resistor to directly power the blower. 2) slightly less HI: passing full power thru the thermal breaker, it should be zero ohms and shouldn't appreciably change the blower speed except for routing power through "more things") 3) medium (thermal plus one resistor in line) 4) low (thermal plus two resistors in line)
From his measurements the resistor itself sounds fine. I measured the dead stop ohms of my blower and it's 1.8. So ohm readings in the 1 ballpark would likely produce useful speeds. However whether it's the right resistor design for this system could be in question. If the first speed below HI seems like not much lower, then that would be the reason. While I like the thermal fuse, I don't know if they intended it to be responsible for one of the speeds.
He still should have HI speed available, even if the resistor module were a random ball of wires shoved into a potato. Assuming said potato isn't a perfect short to ground. However, once you're on HI, the potato is removed from the circuit because of the double pole relay.
EDIT: My resistor vs bobs. Also potato illustration for clarity. NOTE mine's upside down in the image. Bobs thermal fuse is in place of the 5 winding resistor on mine.
Last edited by mike 66 toro; November 22nd, 2023 at 04:24 PM.
Mike, what an amazing bunch of information to wake up to this morning. Happy Thanksgiving everyone Your diagram of my circuit is correct and is what I have. And yes, I have three speeds plus HI on my dial. Nothing at all happens at the lower speeds, and only a loud CLICK from the relay happens on HI. Since this is the second relay I have used with the same results, I'm going to focus on the resistor. I've seen many replacements online that just use a piece of copper wire in place of my small resistor/thermal break, which is interesting to see that you don't have. I'm not getting enough power through the relay to run the blower, whatever that amount should be. I have a couple friends coming over later today who can help with some measurements under the hood as I make changes inside the car, etc. Always helps to have another set of hands, and another set of eyes to make sure I'm not missing something.
Last edited by BSiegPaint; November 23rd, 2023 at 04:06 AM.
I think it's safe to say none of the colorized diagrams are right. For one thing, we have three resistors, not 2 as suggested by the diagram. Also, it seems I have a relay for HI after all, on my 66. I'm tracing things now just to confirm where it is exactly. I think they did a lot of on the fly changes on these!
Looks like you're running into all the same issues as me......the wiring diagram for the '66 Toronado is wildly inaccurate. The relay is on the front fender by the horn relay, if you haven't found it yet.
November 21st, 2023, 09:32 AM
