[xj-s] Mercedes Fan Power Requirements

While I’m putting R-12 into my '83 XJ-S, I look over at the fine
Mercedes fan I’ve been talking about – and it ain’t running. Turns
out that the fuse is blown. Not actually blown so much as worn out;
it looks like it was really marginal, and the constant load
eventually got to it. This is a 20-amp fuse! I didn’t have another
20-amp handy, so I put in a 35; I’d rather have something in between,
perhaps 25. The fan is once again running just fine, but I reiterate
that this Mercedes fan is a seriously heavy-duty beast; I suspect it
draws more amps than the 16" GM fan next to it, but my VOM will only
read up to 10 amps so I can’t check either of them.

I dunno how long the Mercedes fan has been inop, but clearly the 16"
GM fan is adequate to keep this car cool all by itself. Between the
two electric fans and my high-wattage headlights, I’m probably
marginal on the capacity of my 105-amp GM alternator. I clearly
would have been adequately served by a 12" fan with much less power,
but I’m not gonna sit here and complain about too much cooling!

– Kirbert | Palm’s Postulate:
| If anything is to be accomplished,
| some rules must be broken.
| – Kirby Palm, 1979

Kirby,
seems like a pity not to use the MB fan (even if you don’t need it).
How about putting them in series? It would definetely lower the drain
on the electrical system, no idea what effect it would have on the
cooling. Sounds like most of the voltage drop would be across the
GM fan.

Walter

Kirbert wrote:>

While I’m putting R-12 into my '83 XJ-S, I look over at the fine
Mercedes fan I’ve been talking about – and it ain’t running. Turns
out that the fuse is blown. Not actually blown so much as worn out;
it looks like it was really marginal, and the constant load
eventually got to it. This is a 20-amp fuse! I didn’t have another
20-amp handy, so I put in a 35; I’d rather have something in between,
perhaps 25. The fan is once again running just fine, but I reiterate
that this Mercedes fan is a seriously heavy-duty beast; I suspect it
draws more amps than the 16" GM fan next to it, but my VOM will only
read up to 10 amps so I can’t check either of them.

I dunno how long the Mercedes fan has been inop, but clearly the 16"
GM fan is adequate to keep this car cool all by itself. Between the
two electric fans and my high-wattage headlights, I’m probably
marginal on the capacity of my 105-amp GM alternator. I clearly
would have been adequately served by a 12" fan with much less power,
but I’m not gonna sit here and complain about too much cooling!

– Kirbert | Palm’s Postulate:
| If anything is to be accomplished,
| some rules must be broken.
| – Kirby Palm, 1979