Tom Serrago

<center><img src="http://pictureposter.audiworld.com/294/003_0a.jpg"></center><p>Russ, pictured is the current stable:
99.5 A4 TQ 5spd, sport package, 48K miles
85 5KS Avant AT 213K miles

My Audi goals are similar to yours. You can see some cosmetic upgrades/mods to the 85, I also replaced the quad lights with the trapezoids.
I debaged the A4 (left the rings), the exhaust tips are after market, and I did a clear corner mod on the front projectors (removed the orange reflectors to give a Euro look to the lights), installed full window tinting. The engine and mechanicals are completely stock.
I use the Avant for pick up and delivery of the repair work, and it is handy for Home Depot runs. I have no immediate plans to replace the 85, but have started the initial search/fact finding. The wife drives the A4, and if I behave, see lets me drive it too.

Sounds like a good idea to relay the 3 stage, I would guess mine only has 2 also. There should be no problem with the relay aft of the fan motor.

Thanks for mentioning me to Dr. Colin, I'll send him an email.

Speaking of email, send me an email so I can chat more on off topic stuff.

later

Tom

Xel

Ppl like u is the reason why I sold my 1990 200t and bough my current 90:-) When I had the car I was like, man thats a beatiful body style and its been already done 10 years ago, the lines are so smooth and blah blah blah. Then I saw a picture of something like urs:-)

Now when I see pix of a4's and my 90, I have these thoughts coming back:-)

Please dont ruin it for everybody else , lol

Tom Serrago

I hear you
actually, for a 20 yo design, the type 44 still holds up well against the latest designs.
Personally, I like the type 44 Avant design over the C4 &amp; C5 Avants, but I wouldn't hesitate to make an exception for the new RS6 Avant!

RussB

Both of your Audis look very tidy! I've always admired the 5000 Avant. I'll bet that they have an amazing amount of room inside 'em!

I (finally) got my 5000 reassembled and its coolant's temp seems more stable. The location aft of the fan for the stage 3 relay seems a bit kludged, but I can live with it.

Not sure how many stages your 5k's fan has, but I think that it's 3. I think that only the '84 naturally aspirated model had both the smaller cooling fan and only two stages of fan speed. It was always on the hairy edge of overheating during So Fla summers.

Like you, I replaced my 5000's quad headlights with trapezoidal (euro H4's) ones, soon after I bought it. I love the 5000's looks (call me wacky) but hated the looks of the quad headlights.

Oh yeah, YGM.

Tom Serrago

The Avant has quite a bit of space with the rear seats folded down and the cargo cover removed. It's good for hauling 25 bags of mulch from Home Depot, (my flower beds are due again).
Quads were quite the rage in the early 80's. But more than anything else, that head light treatment dated the car.
Hey Russ, if you're wacky, then you're in good company, all the rest of us on this board are too then.
The styling was revolutionary and trend setting. It's the primary reason why I kept mine so long. But time does keep marching on, and I have even begun to appreciate (sort of) the C5 (current A6 styling).
You should be running a lot cooler now, that's good, summer is already in full force it seems.
I know I have 2 good stages, stage 1 when AC is on, and I measure approx 6 volts across the fan motor terminals. When the temp gauge reaches about 11:30, stage 2 kicks in and I measure 9 volts across the terminals. I never measured 12 volts or heard the fan go any faster. I'll have to check current draw next time. On hot days in stop n go driving with the AC on, I see the highest temp readings (approx 12:30) but the fan doesn't seem to be running any faster. I think I'm using a 82C thermostat (its a real drag getting old, memory is failing) maybe that is keeping the coolant temps below stage 3 levels, or the relay is bad, maybe the sensor?

got your email, will ans soon

Tom

RussB

Thanks for the fan voltages, Tom. Now I know what to look for. I've found it difficult to accurately measure high currents in my car, so voltages will have to suffice. I don't have an accurate milliohmmeter; my DVM measures the big blue cooling fan resistor at about 0.7 Ohm per leg. I don't think that this measurement is especially accurate.

If we assume that at the time of measurement you had 13 Volts at the top of the resistor . . . Using Ohm's Law, your measured Voltages at the fan, and assuming 0.7 Ohm per leg for the big blue resistor:

Stage 1 fan current would be 7 Volts (dropped across two resistances) divided by 1.4 Ohm, or 5 Amps.

Stage 2 fan current would be 4 Volts (dropped across one resistance) divided by 0.7 Ohms, or 5.8 Amps -- which seems low.

I don't trust my resistance measurent and suspect that the two resistances may not be the same. I have three spares (I tend to pull everything in sight when I find fresh meat in the junkyard), and will try to measure all of them using my limited instrumentation.


I'm not sure if your stage 3 is working or not. Last night on the way home the fan sounded quiet, so I'd guess that stage 3 never ran. Supposedly it was 87 deg F outside.

The two sets of contacts in the two-stage thermoswitch in the radiator should close at 95 deg C and 102 deg C. The 95 deg C contacts (together with the high pressure switch in the AC ) controls stage 2. The 102 deg C contact controls stage 3. If stage 3 doesn't come on, either the thermoswitch contacts aren't closing, the coolant never hits 102 deg C, or the 3rd stage relay isn't closing.

If your coolant isn't ever hitting 102 deg C, your car's cooling system is in good shape!

tonyj

0.4 Ohms on two of them and 1.0 on the third one.

Tony
'91 100Q 5spd

Tom Serrago

In spite of 3rd stage on mine may be kaput, for now, I'll leave it as is. I'll put on the shopping list a new thermo switch and relay.
I agree 5.8 amps is way low for 2nd stage, but 5 amps for 1st stage sounds right in the ball park.

Hey BTW YGM.

Tom Serrago

If your resistance figures are the same on mine, if I'm doing the math correctly and I rechecked the motor terminal voltages, then for stage 1 6.3=1.8I or I=3.5 amps.
On stage 2 if the 1 ohm resistor is bypassed?
9.4/.8=11.75 amps, does it still seem low even without taking into account any wiring resistance?

I apologize if I'm boring anyone, it's just one of those rare (for me) Sunday afternoons.

RussB

Where's resistor 3? Is it the value that you measured across R1 and R2?