Boh2k

Can someone tell me where the blower motor relay is located at?I'm having a problem with the high on my blower. The setting for low and med work but i get nothing went switched to high!


Parts #TR15885

Thanks in Advance

Lady72nRob71

If this is for your 72 Cutlass, the relay will be over the brake booster.
There should be a thick wire going to the junction block with an inline fuse holder - check those before replacing the relay. If there are splices in the wiring, they better be in good shape and be soldered. If the fuse holder was bypassed, replace it.

With engine off, key in RUN, switch from med-high to high and you should hear a click from the relay.

See what you get...

Oldsguy

welcome to CO.

Boh2k

Thanks Lady72nRob71 I have checked the relay as you mention above and hear the click when moving from med to high on the heater switch!Doe this mean the relay is bad or good?Still nothing on high also the wires look non-raped and i don't see any inline fuse at all when i traced the wire back!

Bluevista

It was the high blower speed inline fuse when I had the same problem.

Jamesbo

x 2

Lady72nRob71

The coil of the relay is good, as well as the dash switch.
There should be a thick wire going from the blower relay to the horn relay-junction block. The inline fuseholder should be there (unless somone removed it.)

Either that fuse is bad, the holder bad, the wiring open, or the blower relay contacts are bad.
Take a look again for the fuseholder - hope it is still there...

Boh2k

That did the trick guys thanks.....but now setting mid high i get nothing every other setting works.I even replaced the relay!This is really starting to get on my nerves!

Bluevista

You didn't loose any of the smoke out of the switch or relay did you?
The resident Classic Oldsmobile electrical experts say that once that happens they're shot.

Fuses are about as deep as I go.

Boh2k

Lady72nRob71

Time to pull out and check the blower resistor, in the eng comptmt on the side of the evaporator case. Should have about 4 wires plugged into it. Sounds like the med-high coil may be open. It will be obvious if so.
It is a little tricky to get to but possible.

FlyBoy72

Rob,

I know this is an older thread but I'm hoping you can help.

I have the same prob as Boh2k. Blower works on 3 low speeds but nothing on high. When switching from med to high the relay by the PB booster clicks. So far, so good

So I've found the in line fuse. Now for the big question: How do I get the in-line fuse holder apart so I can check the fuse. So far I've remain calm, but I'm out of ideas.

Thanks.

jaunty75

What model/year is this car? I just had the same thing happen on my '73 Custom Cruiser. The three lowest fan speeds work, but the highest doesn't.

Have you done the troubleshooting check in the service manual? Does your car have a rear window defogger? If the answer to the latter question is yes and you haven't done the troubleshooting checks in the manual, don't automatically assume that the problem is the fuse. I ran through the troubleshooting sequence for my car, and it's the same for Cutlass for 1973, and the problem points to a failed relay, not a failed fuse. In my case, it was the "hi-blower cutout relay" that failed. I've just ordered a replacement, and it won't be until after I get that and put it in that I'll know for sure if this was the problem.

There is a separate blower motor troubleshooting section in the '73 manual for cars that have both a manual A/C system (not Comfortron) and a rear window defogger.

FlyBoy72

72 Cutlass convert, with A/C, no rear defogger of course.

I did do some trouble shooting (switch OK, resister OK, the hi speed relay by the brake booster makes a click when switching to high speed).

Soooo... low and behold when I finally got the in-line fuse holder apart (without loosing my patients I might add) it was defunct. Put in a new 30amp and BooYah, blowin on high speed.

Thanks for your input anyway. If it wasn't the fuse I was goin your route with the relay replacement

Lady72nRob71

Glad you got it...
Sounds like it was just stuck together. Just make sure the holder was not melted, burned or had its contacts pitted. If you, the holder would need repair or replacement depending on condition.

O's_Car

Hey all, I'm glad I found this thread because I'm in the same boat. I replaced all the wiring in my 70 Cutlass S and there was no fuse in that in-line holder. The Chassis Service Manual says "30 amp fuse" but doesn't specify a part number. I've tried the ones I can find at the parts store (AGC30, SFE30) but they're too long. What fuse goes in there?

FlyBoy72

Oskar,

Glad you found the thread helpful. The guys on Classic Oldsmobile are amazing. The in-line fuse was the problem with mine and I was ready to replace a hole buncha stuff.

Anyway, the fuse you need is an AGA 30 amp (I think it's the shortest fuse you can buy). I bought mine at PepBoys in am assortment of AGA fuses.

O's_Car

Thanks FlyBoy! After I wrote that post I pulled apart the original wire harness (which fortunately I saved) and found an AGA-30 fuse in the old in-line holder. I went out and bought a new one today, put it in the new harness in the car, and now the fan works fine.

I also went back and looked through the Chassis Service Manual again. I did find the fuse type specified in the Air Conditioning section (not the Electrical section where I had been looking), but it specified an AGC-30. Oh well...

bundy

Might as well keep going on this thread. Just starting to work on my 71 Cutlass and none of my blower speeds work. The fuse in the fuse box looks good. Now what ?

Lady72nRob71

Try replacing the fuse with another of same rating. Sometimes they LOOK good but they are crackes at the ends.
Can you get the AC clutch to engage by moving the lever to AC settings?
If not and the fuse is really good, then the main switch ont he control head may be bad.
If the AC clutch can engage, then suspect the fan switch next, esp if you can get a click from the high speed relay on high.
Does your car have a rear defroster? The fan circuit is different on these models.

FlyBoy72

On my 72 Cutlass the three low speeds worked but HI did not. For me it turned out to be an in-line fuse located at the firewall near the distributor. I changed it and that took care of the problem.

As far as the all the speeds not working, perhaps it's a relay. Hard to think it could be the motor itself or the switch.

I'm sure you'll get better info about this on this site. very helpful bunch.

jaunty75

I have the exact same problem on my '73 wagon. Lower three fan speeds work, highest speed doesn't. Can you describe this fuse location at all? Was the wire mounted to the firewall? Any chance you could take a photo of it? I find it difficult sometimes to locate things under the hood with only general descriptions of what they look like. Thank you.

steverw

Jaunty that inline fuse usually runs right along the top of the firewall and over the A/C suitcase/box. The wire is a heavy orange wire. Not sure where it originates from but you cant miss it unless its been removed, replaces with another color wire, taped into another harness or not, just wrapped in tape? Should have a yellowish/whiteish twist open fuse holder in it.

jaunty75

Thanks. I'll give it a look.

73aussie455

Watching this as well, just about to start a new thread when I saw this. Must be a common problem, Hi speed fan on my '73 Delta no worky either..
jaunty75, very interested in your diagnosis and cure as it's put together the same as mine.
Oh, and why is this in the Newbie forum? nearly missed it.

jaunty75

There is another peculiarity about my car's problem. My car also has a rear window defogger. The switch is right above the climate controls. When the defogger is off, the highest fan speed does not work. When the defogger is turned on, the highest fan speed DOES work. This is the opposite, as I understand it, of what's supposed to happen. I think to prevent too much power draw at one time, the defogger and fan speed switches are interlocked so that if the defogger is switched on while the fan is at highest speed, the fan speed automatically drops down a notch.

I'm curious to know if your car has the rear defogger, and, if so, if turning it on will cause the highest fan speed to work.

73aussie455

jaunty yes my car has the rear window defogger, the wire one stuck to the inside of the window and the switch above the A/C & heater controls.
Just checked, the fan Hi speed doesn't work with the defogger on or off. I'm furiously looking through the manuals to see if there is a reference to what you said.

jaunty75

There is a troubleshooting diagnosis chart on page 1B-5 of the '73 chassis service manual, but it was of no help to me because the symptoms my car exhibits are not in any of the four possible sets of conditions the chart shows. That's why I was interested in the earlier comment about the inline fuse. That fuse IS mentioned in the diagnosis chart, but only as a possible cause if the high blower doesn't work at all no matter what position the defogger switch is in.

This actually sounds like the problem you're having--no high blower at all--so maybe the 30-amp fuse is the problem in your case. The actual wording in the manual is "Check 30 amp in-line fuse at junction block." If the fuse is blown, the solution obviously is to replace the fuse but also to look for a short in the "black/orange stripe wire, in-line fuse to HI blower relay." If the fuse is not blown, there is an additional set of diagnosis steps shown in the chart.

73aussie455

thanks for the location in the manual jaunty. Just checked the fuse and its good. looking at the Hi blower relay now. earlier post refers to whether the A/C clutch works, mine does.
Also need to check the operation of the rear defogger, never tried it so I'm not sure if it's working either.
I'll post a reply when I can sort it out

Just noticed the rear defogger dash switch has a red 'ON' indicator light behind it, nice.

jaunty75

Where, exactly, is this fuse located under the hood? Thanks.

73aussie455

There are only 2 inline fuses I can find under the hood, one is a 5A and the one in the center of the pic is a 30A. I traced it as best I could and it does go to the relays. I know I shouldn't but I'm assuming it's the one.

P1340_29-10-14_zpsca843217.jpg

jaunty75

Thanks! I found both fuses, too, a 5A and a 30A, and both are fine. I didn't really think my 30A was bad because then I would have thought the high blower wouldn't work at all. But as I say, mine DOES work if the defogger switch is also turned on. (I have the little red light, too.)

So I still don't know what the H is going on.

73aussie455

Lol, oh the joys of a 40+ y.o. car hobby..

73aussie455

Jaunty, I found this NOS part in a for sale ad on google. Part of the instructions reads, "When installing the high blower override switch...", the part is for Old's '73 full size models with manual A/C.
This would confirm your understanding of the Hi blower override function. Now it would seem I have a new problem with mine.

_574_zps9ae276ce.jpg

ralbers

Hey Guys, My in line fuse holder is shot (and so was the fused-fuse when I finally got it apart). Does anyone have access to short half of the fuse holder pigtail?
1973 Delta 88 Royale Convertible 350.