98 Olds 88 LS Blower Motor Replacement

I need a little help getting at the blower motor in this car. I've taken off a couple of plastic cover pieces at the bottom of the dash, and it looks to me that the blower motor is inserted with the fan facing towards the passenger side, but I can' tsee any way of getting at it. There are other plastic parts underneath the dash roughly in the middle (over the hump) that look to me like they have to come off, but I don't see any bolts holding the darn things up. Can someone shed some light on how to get at this motor?

By the way the motor still works in the three lower speeds but not the high speed and it makes a grinding noise. I know the motor has to be replaced because when I turn it right off the grinding noise stops. I may also need to replace the resistor, but am trying to get the motor replaced first to see if everything is OK just by replacing the motor. If not, then I'll do the resistor as well. I have bought the motor already. I've replaced one in a different car (Ford) and it wasn't anything as difficult as this one!

Thanks,

QC

Isn't an '98 C/H car blower motor still under the hood? Could be why you can't find it under the dash....

I suppose that depends on the model, doesn't it? I replaced one under the dash of late 80's Ford years ago !!!

But I'll have a look under the hood, just in case.

After looking under the hood, I do see what appears to be the end of the blower motor (with the electrical connection). It is mounted onto the firewall near the centre but there is a steel bracket right in front of it coming up from the rear of the engine block that prevents removal of the old and installation of the new unit. This bracket supports two hoses and the O2 sensor cable. Can this bracket be removed to get access to the blower? How?

Thanks

You should be able to just bend it- then put it back when you're finished-- removing the crossbar (from across the shock towers) also is a big help

Thanks, brcidd, I'll see if I can bend it tomorrow. I don't suppose that it's bolted to the block so it could be removed, huh? I wasn't able to feel any bolts there and of course can't see in there!

Alright here's an update on my project.

I was able to remove the bar across the top of engine compartment and the bracket supporting tubes and cables from in front of the blower motor (I tried to bend it but it was too hard - the steel is quite thick). The bracket is secured with two nuts to bolts welded to the engine block. Unfortunately one of the nuts and a socket and extension fell down into the engine area and I suspect they're all on top of the plastic cover under the engine. Now I'll have to take that off to recover the nut and tools. Shucks.

I ran into a little problem besides that. I was able to salvage the rubber gaskets to mount the new motor, but the plastic cover over the motor broke at the small tube that the rubber tube connects to. The plastic is brittle after ten years of use and just broke off leaving a hole in the plastic cover! I called the dealer (this is a dealer part only) and they want $70 for that piece of crap which has to be ordered. I paid $68.00 for an aftermarket blower motor. Isn't that insane?

Is there a good place to get that part (part number 52-468-407 from for a reasonable price? What is the function of the small rubber tube coming back into the blower motor anyways? Could that not simply be plugged?

Thanks,

QC

Does nayone know what this small tube does coming back into the motor cover? is it for A/C recycling setting?

I am wondering if I can just plug that hole or if I should pick up a fibreglass kit and repair it! There is no way i'm going to pay $70.00 for a cheap piece of GM plastic, lol.

Thanks

QC

That tube serves as ventilation for the blower motor windings- you can run without it- Probably won't hurt anything- just lessens the life of the new blower motor- but if you have a guarentee.........anyway- changing the HVAC module cover would not be fun....Since it is your own car- I'd fashion a repair to the tube and nipple......

I was afraid it might be for that purpose, I was hoping not, though. If that's the purpose of the tube, then I better not close it off - I know what excess heat can do to a motor. Likewise dust can do a lot of damage to a motor too and hence the need for the blower cover. I'm off to a hardware store to find a good epoxy to effect repairs to that small spout (or nipple) then. Thanks again.

QC

OK, I've repaired the plastic cover and everything is back under the hood. This was a much more difficult job than I had figured on.

The noise is gone and the blower even works on high speed, but only when it feels like it. So now I need to get a new resistor under the dash. :disappoin At least I still have the underdash stuff taken apart.

QC

So now I need to get a new resistor under the dash. :disappoin At least I still have the underdash stuff taken apart. QC :shakehead
IIRC, and you have the manual fan control, the resistors are under the hood mounted in the fan box on the firewall. Look to the left of where the fan is, there should be two, one for low speeds and one for high speed. BTW, you can put the "underdash stuff" back together! :grinyes:

OK, thanks, I am going to order the resistor tomorrow and see if I can find a similar part there.

Right to the left of the blower cover, there is a fuse box, is that where you say the resistors are HotZ28?

With brcidd's and your help, I'll get there yet.

Thanks,

QC

just follow the blower motor wire back to the resistor.....its mounted in the HVAC module- up on top- below relay center

Thanks, brcidd.

I've never had to replace one of these resistors before on any of the dozen or so cars I've owned from cradle to grave (but then I've never owned a lemon as bad as this 98 Olds 88 before, LOL).

I've read that they are under the dash in some cars and I've read that they're mounted on top of the A/C unit under the hood to keep them cool because they tend to heat up quite a bit from providing the resistance for the lower fan speeds. So it sounds like this one is under the hood. I'm picking up the new unit later today, then I'll give it a whirl.

QC

After further thought, I am not sure the blower uses a resistor for high-speed, only the three low-speeds. You may have a bad high-speed relay, or loose/burned wire somewhere!

OK I've replaced the resistor, it was almost as hard to replace as the blower motor! It was also quite corroded. GM makes these things out of steel instead of copper or aluminum so rusting is a problem with them. The resistor has three coils, one for each of the lower speeds. I figure if the current does not pass through the resistor for the high speed the rust should not have affected it, but if it does, then that would explain why the fourth speed only worked sometimes - the rust was providing some resistance preventing enough current to pass through to run the fan at full throttle. So far so good, let's see if the problem is solved permanently. If not, it may be the relay as you say, HotZ28.

I've even put the underdash stuff all back on - gosh, I wish I was more flexible!

Thanks again,

QC

My fan no longer works on any speed. It did at first, then it worked on high only, now nothing.

A few years ago I had some wiring repairs done in a repair garage and was charged four hours labor, three to diagnose and one to repair wires at a harness underneath the dash. Looks like I put the dash parts back too soon, LOL. I think it's the wires again now. I don't want to go and pay those dudes several hunderd dollars again for job that doesn't last. Any suggestions where to start looking for the lose/burnt wires?

I took the relay box apart and put it back together as I could not see anything wrong with it. I opened up a couple of modules each with a fuse that I thought may have been the problem, for A/C and fan motor. Both fuses looked good so I pushed them back in and put everything back the way it was. Now the high speed works fine (at least so far!) but none of the other speeds still work! Could this be the relay? It seems to me that current is now getting through to the motor to run it at high speed (bypassing the resistor), but something is keeping the current from going through to the motor for the other three speeds. I've replaced the resistor twice. The first time I thought the resistor might have been faulty so I got a replacement and put that in, with the same results. So unless I got two faulty resistors both of which looked good to me (highly unlikely), something else is causing the problem. I just don't understand exactly what the function of the relay is. Can someone shed some light on this?

Thanks

The pic below may not be model specific, but it is a good indication of the manual fan control relay location and associated wiring/terminals. Have you looked at the wiring/terminal going to the resistor? These carry a lot of ampherage, especially when a motor is failing. A common problem with this set-up is; once the terminal and wires overheat, it will cause damage to both. When this happens, you will have to replace the terminal with new unit. They come from the dealer with the terminal and about 1-ft of wiring to splice into your existing wires after you cut the old terminal off. Have you changed the relays with another relay from the same area. All of them are the same, so you can just swap one from the horn or from some other function for testing purposes.


http://img255.imageshack.us/img255/1/blowerresistorandrelayspr5.jpg


ACDelco Part # PT391

http://198.208.187.182/servlet/com.entigo.acdelcocatalog.servlet.ProcessImageServ let?languagecd=EN&countrycd=US&user=InternetUser&mfgname=null&prodlinecd=null&acpartnbr=PT391

Thanks.

I took apart the larger boxes above the small ones and they have fuses in them. Everything looked OK to me.

The smaller ones you show in the picture I just pulled out and looked at them and saw no wires burned or loose, so I just put them back where they were. I don't think they were marked as to what each one was for. I have not switched them as you suggest, but maybe I'll do that. The funny thing is it appears that something got modified just by pulling them out and putting them back because the high fan speed didn't work prior to that and it's working now - this suggests something is loose! I'll have to have a closer look. Maybe one of them is in fact damaged.

The terminal going to the resistor looked Ok too when I replaced the resistor. I may have to look at that again too, maybe I missed something there.

I have a multimeter. Is there a way to check for continuity at the various terminals?