1987 radiator fan

[vana_goner]

No fan. Factory AC. With the engine running, I jumped the relay/resistor behind driver headlights. Nothing. Reconnected wire harness. Jumped the thermostat switch on the radiator. Nothing. Does this eliminate the relay as a source of the problem? Does this mean my fan motor is kaput? If so, should I replace the relay when I swap out my fan?
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'87 Syncro
Tiico engine conversion replaced by Subaru 2.5
Subjugated to Vanagon vagaries

[crazyvwvanman]

Commonly this will either be blown fuse #1 in the main fuse/relay panel or a bad ground for the rad fan motor, at the ground tree near the fuse/relay panel.

Mark

[vana_goner]

Mark, thank you for the quick response! I rechecked # 1 fuse and it is fine. Checked ground and it appears to be fine. Thoughts?
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'87 Syncro
Tiico engine conversion replaced by Subaru 2.5
Subjugated to Vanagon vagaries

[crazyvwvanman]

The fan motor has 2 threaded posts where wires attach. The red wires are 12v from the switches. The brown is the ground wire to near the fuse panel. Use a voltmeter to test. Or run a test known hot lead and a test known ground lead. My bet is on the ground but who knows?

Mark

[bluebus86]

[vana_goner]

Thank you for the suggestion. I'll do that.
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'87 Syncro
Tiico engine conversion replaced by Subaru 2.5
Subjugated to Vanagon vagaries

[vana_goner]

Tested the fan ground (tested all grounds behind the fuse panel. 😃 Thank you for the direction!). The circuit is complete. Further suggestions? Thank you, Rich
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'87 Syncro
Tiico engine conversion replaced by Subaru 2.5
Subjugated to Vanagon vagaries

[MarkWard]

Maybe the fan died? If you are unsure of your testing with the volt meter, try running the fan with a separate power and ground. A jump box if you have access to one would be quick and easy.
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☮️

[vana_goner]

Straight jumped the fan motor and it runs. Time to go back through relay/resistor and thermostat switch. At least it doesn't look like the fan motor is the problem.
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'87 Syncro
Tiico engine conversion replaced by Subaru 2.5
Subjugated to Vanagon vagaries

[greebly]

You need a multimeter. You can get one free at Harbour freight with a coupon while purchasing something else you can use or need. See if you have positive 12 volts DC at the radiator thermoswitch harness. If so, then there is a break in the wire to the fan.

[wesitarz]

Jump + at the rad thermoswitch connector and with a 12v test light/multimeter you can test for voltage at the resistor. You should be able to hear the relay clicking (the one on the fuse panel I think). The rad thermoswitch and the relay are cheap and easy enough to replace. When you turn on the A/C do you get low speed rad fan on?

[vana_goner]

Thank you all again for all the help! Once I jumped the fan motor with jumper cables, confirmed I had a good ground from the fan motor, jumped across the thermostat switch and heard the click in the resistor behind the headlight, I turned my search back to the battery. Sure enough, one of the connectors to the positive had come loose. I snapped a new connector on, tightened the new connector the battery and when I jumped across the thermostat I had a fan. I replaced the thermostat switch and the thermostat at the water pump (just because) and filled and bled the coolant system using the rear-raised (opposite of Bentley) bleeding system. Powered up a climb and watched the temp gage. The temp rose, then fell when the thermostat opened. Temp rose again until the fan came on. Never got up into the hot range and dropped below halfway once I started back downhill. FANTASTIC!! Thank you again! Now, onto the headlight issue . . .
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'87 Syncro
Tiico engine conversion replaced by Subaru 2.5
Subjugated to Vanagon vagaries

[crazyvwvanman]

That extra red wire at the battery is only for the high speed setting of the fan. Your fan should have run on low speed even without that wire connected.

When you pull the connector off the radiator temp switch there are 3 wires in the harness. Jumper between any 2. There are 3 combinations of 2 so try all 3. One should do nothing, one should run low speed fan, and one should make the relay click on for high speed.

If high speed works but low doesn't it is almost always going to be the resistor behind the headlight has failed. High speed bypasses the resistor.

Mark

[1975 Kombi]

I have an 87 Vanagon without A/C and would like to know the location of the fan relays and how to get to the rad fan? Thanks
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Brett

“He’s decieving you boy! Reach into his pocket and take what he’s got.” Mr. Crabbs.

75 Westy auto
03 Jetta TDI
71 SB
74 Westy
Licensed pilot (single engine land VFR)
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Rust In Pieces: 72 Bug, 73 Bug, 81 Rabbit LS D 2D, 83 Rabbit D 2D, 84 Jetta TD GL, 85 Jetta D, 68 Z28 RS 302, 91 Passat 16v