1986 Daihatsu Skywing - Ignition on Fan Relay Supply?

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Sun 8 Nov 2020 11:18
1986 Daihatsu Skywing - Ignition on Fan Relay Supply? - edlithgow

Severe overheating on first Inspection attempt, which was aborted.

Direct connection to fan got me home, and a (somewhat hidden) manually switched substitution for the relay got through a second inspection. Always-on is, however, extra wear on the old radiator fan and I'm likely to forget to disconnect it and flatten the battery

The overheating has happened before and if it keeps happening I'm going to bust the head gasket, (traditionally fragile on these 3-cyl engines), assuming I havn't already

Last time I fixed it by re-making the connection to the engine temperature sensor which controls the fan relay. Relay and the sensor bench test OK.

This time, while fiddling with the connection to the (separate) sensor for the temperature gauge, which has never worked, the dial needle moved, and the fan started to work, though this did not last.This suggests to me a short in the wiring loom.

Pending unwrapping and tracing the loom, I'm thinking an ignition-on supply to the relay would at least avoid the battery-flattening risk.

Are these piggy-back fuze holders the best way to do this?

www.ebay.com/itm/5-x-Add-a-Circuit-Fuse-Tap-Piggy-...8

If I can't get them here postage shouldn't be too bad for something that small.

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Sun 8 Nov 2020 15:38
1986 Daihatsu Skywing - Ignition on Fan Relay Supply? - Bolt

Severe overheating on first Inspection attempt, which was aborted.

Direct connection to fan got me home, and a (somewhat hidden) manually switched substitution for the relay got through a second inspection. Always-on is, however, extra wear on the old radiator fan and I'm likely to forget to disconnect it and flatten the battery

The overheating has happened before and if it keeps happening I'm going to bust the head gasket, (traditionally fragile on these 3-cyl engines), assuming I havn't already

Last time I fixed it by re-making the connection to the engine temperature sensor which controls the fan relay. Relay and the sensor bench test OK.

This time, while fiddling with the connection to the (separate) sensor for the temperature gauge, which has never worked, the dial needle moved, and the fan started to work, though this did not last.This suggests to me a short in the wiring loom.

Pending unwrapping and tracing the loom, I'm thinking an ignition-on supply to the relay would at least avoid the battery-flattening risk.

Are these piggy-back fuze holders the best way to do this?

www.ebay.com/itm/5-x-Add-a-Circuit-Fuse-Tap-Piggy-...8

If I can't get them here postage shouldn't be too bad for something that small.

I know I`m not you, but I wouldn`t use a bullet connector, I have always found them to be the least reliable connector there is, if nothing else available I would twist wires together and use shrink cable covering. imo much safer.....?

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Mon 9 Nov 2020 01:12
1986 Daihatsu Skywing - Ignition on Fan Relay Supply? - edlithgow

Thanks. The piggy-back fuse things may be available with other connectors. I'll have a look.

IIRC the connection to the temperature switch (long gone) was a bullet connector,. I improvised something with the spring from the inside of a ball point pen which seemed fairly secure but may be part of the current problem. (NPI)

Scotty Kilmer, who is irritating but probably not as daft as he acts, uses those (deprecated for automotive use) "wire nuts" here and a solderless splice connector for an AC control bypass lashup.

www.youtube.com/watch?v=DAOA5fP4Wvk

I could always solder it if necessary.

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