Toyota Celica Supra Forum banner

85 Supra -Condensor motor replacement?

6K views 20 replies 8 participants last post by  drjim 
#1 ·
Hey everyone....

I am in the midst of re-cooling my 85, (condensor, compressor, expansion valve, etc) and my condensor fan sounds awful. I have thoroughly mangled the nut holding the fan on the motor (yay me!), and was hoping to find someone who knows of a replacement? I might be able to get the fan off-so a "bolt in" motor replacement is ok-if its the best I am gonna do. THANKS!
 
#2 ·
#3 ·
#5 ·
Sooo...thanks to the replies and the info-the knowledge base her is great!
Does anyone have any technical specifications on the resistor in this setup? PN 886351-4060-i beleive. Mine has snapped a contact clean off and I doubt I can resolder.
I tried cleaning the space between the actual fan, and the motor housing-and when powered with a train transformer-it sounded a whole lot better. My thought is to re-install, but with thumb screws-in anticipation of sourcing a replacement. I am also going to make a hardware cloth screen for my new condenser-in anticipation of the fan flying off of the shaft-due to the damage I caused in dis-assembly. Any tech specs on that resistor (or link, etc.) really appreciated.
THANKS!!
 
#7 ·
Is there a resistor in the condenser motor fan circuit?
I didn't know that there was one!
http://www.cygnusx1.net/Supra/Library/TSRM/MK2/manual.aspx?S=E&P=7
What he said!

I went out and had a look at my cars and darned if you're not right!
I thought that it was the fusible link but it's definitely not.

I ohm'd it out with a good quality meter and it measured about 0.1 ohm. It's hard to be more accurate. Then I got a good photo of the part and it appears to be 0.13 Ohm (130 mOhm).

Auto part Automotive fuel system

It's obviously 0.13 Ohms and if I were to guess from the shape it's probably a wire wound ceramic cement encased power resister rated at about 1 to 5 Watts.
They are reasonably uncommon. I would imagine that something like:

https://www.digikey.com/product-det...nents/PAC500001307FAC000/PPC5D.13CT-ND/596406


Vishay PAC500001307FAC000
RES 0.13 OHM 5W 1% AXIAL
130 mOhms ±1% 5W Through Hole Resistor Axial Flame Retardant Coating, Pulse Withstanding, Safety Wirewound

would work. They are quite inexpensive at US$1.24 each.

You would have to make it weather resistant by shrink wrapping it or some other means. I would order a few of them and try to use them before making a permanent enclosure to see how hot they get. If they run really hot, by wrapping them you could make them run even hotter and possibly run the risk of them catching fire!
The current flow through the resistor will determine the actual wattage dissipation. The motor resistance plus the 0.13 ohm of the resistor will set the current flow.
12.6V / Total resistance (0.13 plus motor resistance) =Circuit current flow.
Power dissipation is (I x I)/R where I is current in Amps and R is the 0.13 Ohms of the Resistor
(help me out here guys - I'm REALLY rusty doing these calculations!)
I could actually go out and measure the circuit resistance, but i put the plastic cover back in place and I'm too lazy to take it off again. Sigh.

Let us know what you try.

Dale
 
#8 ·
Dale,that is a good and inexpensive solution!
The old broken one is ceramic and about 5 watts.

A resister is a CURRENT LIMITER,not a voltage drop component and it's important,I guess.
My De Rail unit works as is, through the existing wiring. It must go through that resistor!
I checked 17 sites for that part # 88635-14060. NADA!

My way of mounting would be the same way:With a metal strap. Just use galvanized plumbing pipe hanger stuff.
Heat shrink will melt away asap.It's going to get HOT.
Again,excellent solution,Dale.
 
#9 ·
Well, I'm wondering what the resistor is actually for.
I'm assuming that it's in the circuit in case of the motor going dead short. There is a fuse in the circuit, but I would assume that the resistor is to keep the current limited to a value that will blow the fuse quickly, but not enough to melt wiring. I really am curious as to the resistance of the motor to find out what the current draw is for a normally working fan.
 
#11 ·
Well, I measured the static resistance of the stock motor and it is 1.4 ohms. When the circuit is first activated, the voltage divider effect of a 0.13 ohm resistor in series with the 1.4 ohms motor will draw 8.2 Amps. This results in about 1.1V drop over the 0.13 ohm resistor which generates 8.7W of heat from the resistor. Normally you would want to double the wattage rating of the resistor so there is a safety margin to prevent the resistor burning up.

However, once the motor starts running, the inductive load of the motor generates a back-EMF which effectively reduces the current load of the motor. How much?
Well, I fired up the car and turned the air conditioning on so the condenser fan was running and after 5 minutes one could feel heat being generated in the 0.13 ohm resistor, but I could easily keep my finger on it without burning myself. It was merely warm to the touch.

I wasn't going to take the harness apart to measure the voltage drop over the resistor to get an indication of the circuit current, but based on the temperature, I would be surprised if the resistor was dissipating more than 2W of heat. A 5W rated resistor should be very safe.

My biggest concern would be weather proofing the resistor and connector so that water doesn't short the resistor. I suspect that Heat Shrink Tubing would do an adequate job, but water can be difficult to seal out.

Dale
 
#13 ·
Yeah, they look suspiciously similar to the Toyota resistor in shape and texture. The only things different are the axial leads. These have the leads exposed. On the Toyota, they are covered and attach to a shielded wire where they attach to the connectors.

I don't know what effect a change from 0.13 ohm to 1 ohm would do to the fan speed. This may be significant. I was hunting for these in the sub-one ohm range and they seem to be somewhat harder to find than they used to be!
 
#15 ·
No I hadn't. They might mount better than the ceramic rectangular ones too.
I like the rectangular ceramic ones because they look closer to the stock shape, but I would imagine that any of these would work nicely.

You know things have changed SO much from when I was involved with electronics. All the manufacturers have merged/been bought/chapter 11'd that I don't know this market at all. I thought that the rectangular ceramic resistors would be easy to find, but they are quite rare! The vendor that makes something the closest, is from Finland, and try to find a distributor here. Sigh.
 
#16 ·
I use those"Dale" resistors in my solar panel set up for a DUMP LOAD when they try to overcharge.
Mounted on an aluminum board,they dissipate heat well.

The other issue is that they have bare wires sticking out.
I soldered them with solid copper wires to my dump load. I didn't heat shrink them at all.
14 G, insulated wires could be used,easily.Then,heat shrink.Add connectors.
https://i.imgur.com/bwTeFWE.jpg
I make a LOT more power than I can use sometimes ,and it has to go somewhere.Into those resistors and a fan and a Halogen head light bulb! Out put is 700 watts PEAK.I usually use only 250 watts.

If you use 2 resistors in parallel,the wattage goes up,but resistance goes down. I went through that math BS a few times to get the correct resistance in parallel.

Use the Dale resistors=WAY better.
 
#17 · (Edited)
#18 ·
I would also try to find a ceramic type just to keep it stock, but from the ones I saw browsing, none had the spacers (bumps) to ensure that it wouldn't move in the holder.
That's a very good observation.

I looked at the original in my car and it almost looks like Toyota added a separate ceramic piece to a standard ceramic resistor.

Auto part Automotive fuel system


Could the ceramic part with the bumps be removed from the broken resistor and glued onto a new ceramic resistor?
I don't know what glue one would use, but there must be a ceramic glue that would work.

I have been thinking about how Toyota weather proofed the bare wires, and it appears to be Glyptal painted onto the wires.

https://www.electro-wind.com/glypta...oating-130-c-red-aerosol-spray-can-361-g.html
It's extremely expensive, but from the description it is used as an electrical insulator and a weather sealer. It is also described as an adhesive so I wonder if this could be used to adhere ceramic to ceramic.

https://www.usbr.gov/power/data/fist/fist_vol_3/vol3-18.pdf
This article indicates that electrical transmission companies use "epoxy" materials to reattach broken porcelain although they paint porcelain with Glyptal to improve resistance to minor defects.
 
#19 ·
The value of the resistor is chosen as the best compromise between limiting the startup current surge which can be 3 or 4 times what the running current is and its effect on the speed of the motor. Adding the resistor means that a smaller gauge wire can safely be used than without it. There's more than one reason that that's a good choice like cost, weight, space available, ease of installation.... I seriously doubt that an exact match is critical. Toyota likely sourced whatever was available closest to the theoretical ideal value vs having custom ones made.
 
#21 ·
Glyptal is expensive because it's a proprietary product. "Liquid Electrical Tape" or "PlastiDip" would both be suitable replacements. Just make sure you clean the parts well before applying it to get any grease or oil off the parts.

I've been using the ceramic "Sand Block" type of resistors since the early 1960's, and I've seen them in 30's~40's radio gear, so they've been around quite a while. Nothing 'magic' about them, except that they used to be dirt-cheap!

- Jim
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top