a/c condenser shield
09-14-2013, 11:42 AM
#16
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Thread Starter
I'm not saying it's not a great idea.....
I'm just trying to envision the failure mode that allows that arm to contact the A/C condenser.
I've replaced more than a couple of these condensers, from the arm coming off once the circlips are gone.....I've seen this failure "punch" that rod through both the condenser and the radiator.....very ugly....very expensive.
I'll have to go look at a vehicle to see how the splined arm can hit the condenser without anything coming loose.
Before I go look....help me get my head "around this"......why wouldn't this happen in "normal" operation and only happen when the motor gets "stuck" and runs continuously?
I'm just trying to envision the failure mode that allows that arm to contact the A/C condenser.
I've replaced more than a couple of these condensers, from the arm coming off once the circlips are gone.....I've seen this failure "punch" that rod through both the condenser and the radiator.....very ugly....very expensive.
I'll have to go look at a vehicle to see how the splined arm can hit the condenser without anything coming loose.
Before I go look....help me get my head "around this"......why wouldn't this happen in "normal" operation and only happen when the motor gets "stuck" and runs continuously?
In my case, the failure occurred when the diode in the DRL relay failed and allowed current to flow backwards. This prevented the motor from stopping after it passed the contact points on the motor's internal wipers that say "stop!" It just kept right on going around and impacted the condenser.
A one in a million failure you say? Possibly, but there were two this week alone. I know it was the arm attached to the motor and not the arm attached to the arm because I had to pry the arm from the motor out of the condenser after pulling power to the motor. It makes a big freaking mess when that condenser goes I'll tell you!
On the plus side, I now have taken a new part of my car off and get to understand what is under everything.
I will have these for sale through Roger if interested. No idea of price yet but like you, I am going to end up spending more developing it than I will ever make.
09-24-2013, 06:15 PM
#17
Rennlist Member
Thread Starter
I have got the final version installed and it appears to be a good idea.
Solid bars are spaced over tubes and openings over openings. Laser cut stainless steel. I can paint it black for you if you really want it at no charge but you'll just be getting a rattle can paint job, no powder coating.
I have made up 10 kits if anyone is interested in purchasing. $25 for the kit plus say $5.15 freight for a priority mail box. Kit is laser cut 3mm stainless steel plate, two radiator zips, two zip ties and some peace of mind.
You install it by passing the holders through the condenser and pushing the zip fitting on. I went from the back side while condenser was out but you could go from the front. Loosen your two condenser top mounts and you can wiggle your condenser forward a bit to push the fitting on. It takes about 5 min total to do. Zip tie the two right holes to the curved condenser tubes. The motor arm retracts and just comes right up to but doesn't touch it when lights are down. No way, no how the motor arm will cut through this stainless plate.
All in all this little fiasco of the arm taking a holiday in condenser country would have cost me about $1500+ at a shop to fix. New condenser is $1000, used $25-$275 depending on what you can find. AC recharge was $160. I did all my own labor and took about 1.5 hours taking off and 1.5 hours putting on so there's another $300 at a shop.
$25 is pretty cheap peace of mind for this.
Solid bars are spaced over tubes and openings over openings. Laser cut stainless steel. I can paint it black for you if you really want it at no charge but you'll just be getting a rattle can paint job, no powder coating.
I have made up 10 kits if anyone is interested in purchasing. $25 for the kit plus say $5.15 freight for a priority mail box. Kit is laser cut 3mm stainless steel plate, two radiator zips, two zip ties and some peace of mind.
You install it by passing the holders through the condenser and pushing the zip fitting on. I went from the back side while condenser was out but you could go from the front. Loosen your two condenser top mounts and you can wiggle your condenser forward a bit to push the fitting on. It takes about 5 min total to do. Zip tie the two right holes to the curved condenser tubes. The motor arm retracts and just comes right up to but doesn't touch it when lights are down. No way, no how the motor arm will cut through this stainless plate.
All in all this little fiasco of the arm taking a holiday in condenser country would have cost me about $1500+ at a shop to fix. New condenser is $1000, used $25-$275 depending on what you can find. AC recharge was $160. I did all my own labor and took about 1.5 hours taking off and 1.5 hours putting on so there's another $300 at a shop.
$25 is pretty cheap peace of mind for this.
09-24-2013, 10:52 PM
#18
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Thanks for doing this Jeff. I've ordered mine by PM.
@Greg: The only thing that stops the motor from continuing to rotate its arm into the condenser coil is the standard electrical control, which failed in mine as well. Actually more accurately the PO had installed the wrong DRL relay in (minus diode) and a new one was defective. The headlight connection remained attached (clips all intact and in place), and indeed to headlights started to tilt back as the arm headed down the back side.
As Jeff said, the motor really jams it in there. I had to pull the fuse too to unpower it and rotate the arm back. Fighting with it while under power was a finger-threatening experience that left little doubt as to the tenacity of the motor to act if not told to stop...
@Greg: The only thing that stops the motor from continuing to rotate its arm into the condenser coil is the standard electrical control, which failed in mine as well. Actually more accurately the PO had installed the wrong DRL relay in (minus diode) and a new one was defective. The headlight connection remained attached (clips all intact and in place), and indeed to headlights started to tilt back as the arm headed down the back side.
As Jeff said, the motor really jams it in there. I had to pull the fuse too to unpower it and rotate the arm back. Fighting with it while under power was a finger-threatening experience that left little doubt as to the tenacity of the motor to act if not told to stop...
11-10-2013, 10:40 AM
#19
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An update - I installed Jeff's shield on my '90. It looks almost robust enough to stop a bullet 
Jeff shows installing it when the condenser is out of the car (above), but also provides instructions on how to do it when the condenser is in the car. I found I had to do a few extra things:
All installed now and ready to protect!
Jeff shows installing it when the condenser is out of the car (above), but also provides instructions on how to do it when the condenser is in the car. I found I had to do a few extra things:
- Remove the top shroud between the condenser and radiator
- Disconnect the two struts at the top of the condenser to lean it forward a bit to get some more working room
- Trim the pass-thru radiator ties that go through the condenser before inserting them, otherwise they have to take a 90 degree bend, and the end tab breaks if you try to get it around the sharp bend - found that out with the first one...
All installed now and ready to protect!
04-17-2017, 02:17 PM
#21
Rennlist Member
Thread Starter
Yep. Do you want one? Well actually that's probably a pretty dumb question it sounds like you do want one. Just send me details and I can send you one. I think I was asking $25 for the kit
04-18-2017, 04:22 PM
#22
Burning Brakes
Good idea on the shield!
Jeff you should note that this would be for S4 ('87) and up as the earlier cars have a fully rotating motor (shorter condenser).
One question, what would the strain of hitting the shield do to the motor and or moving parts, blow fuse?
Thanks,
Dave
Jeff you should note that this would be for S4 ('87) and up as the earlier cars have a fully rotating motor (shorter condenser).
One question, what would the strain of hitting the shield do to the motor and or moving parts, blow fuse?
Thanks,
Dave
One word of caution.
You should really consider wearing steel toed boots when doing mechanical work. It looks like you really take care of your feet.
05-14-2019, 06:37 PM
#23
3rd Gear
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Hey Jeff,
If ya still have any of these shields left I NEED one!!! I had the "dreaded motor over run" on my '91 S4 and LUCKILY didn't rupture the condenser. The motor arm happened to strike it between two tube rows, and while it tore a few fins loose, it doesn't appear to have ruptured anything - WHEW!!! I drove it during the day to verify no leaks when pressures are up and - so far - all seems OK. But I'm still trying to figure out what caused the problem - I have no DRL relay. I'm thinking maybe the light combo relay has gone south...
Anyway, please let me know if you have any shield kits left and how to do a transaction with you (or through Roger if you prefer) for one.
Thanks,
David
If ya still have any of these shields left I NEED one!!! I had the "dreaded motor over run" on my '91 S4 and LUCKILY didn't rupture the condenser. The motor arm happened to strike it between two tube rows, and while it tore a few fins loose, it doesn't appear to have ruptured anything - WHEW!!! I drove it during the day to verify no leaks when pressures are up and - so far - all seems OK. But I'm still trying to figure out what caused the problem - I have no DRL relay. I'm thinking maybe the light combo relay has gone south...
Anyway, please let me know if you have any shield kits left and how to do a transaction with you (or through Roger if you prefer) for one.
Thanks,
David
