Matty80
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Re: Spotlight Relay
I've been following this for a little bit and it seems to me that there are 3 tests that have not been mentioned???
I've listed them below and tried to give the best layman's description as possible, please be safe when working on life systems regardless of voltage!
To blow a 70A fuse from a set of spotties is unlikely - I would suspect earth fault within one or both of the spotlights!!!
Secondly, most of those standard relays are only rated for say 35A to 40A. So with a 70A short circuit current or greater, I'd suspect the relay is shagged!!!
As an electrician - the faults and symptoms describe indicate to me that the spotlight wiring is shorted, most probably inside spotlight due to water dunking, this and overloaded a 70A fuse and as such destroyed the relay. Inturn, it may have burned a wire somewhere. Listsed below is what I would do!
Check 1 - For presence of earth fault
1. Disconnect positive of spotlights from relay, pin 87.
2. Disconnect negative of spotlights from body earth.
3. use multimeter and test ohms from positive wire to body earth
4. use multimeter and test ohms from negative wire to body earth
if either of these result in anything but an OL (overload - very high ohm reading) then you have earth fault either internal to a spotlight or within the spotlight wiring.
Do not proceed to check 2, the fault needs to be found and fixed before check two, otherwise will only result in more blown fuses
Check 2 - Spotlight globes functioning
1. Reconnect the negative wire from spotlights to earth, preferrable direct to battery (this being better wiring practice).
2. Disconnect spotlight supply wire from pin 30 of relay.
3. connect positive to spotlight directly to supply wire.
this will enliminate your relay from the circuit and allow only the spotties to be checked. if the fuse blows you have a fault in the spotlights or wiring.
if the fuse doesn't blow and the spotlights don't work - loose wiring, busted globes and or bad connections.
if the fuse doesn't blow and the spotties come on then its most probably the relay (see check 3).
Check 3 - Correct Relay Operation
1. Disconnect wires from pins 30 and 87 on relay.
2. Connect multimeter leads to relay. 1 lead to 30 and the other lead to 87.
3. set multimeter to ohms
4. activate relay and deactive
5. multimeter should alternate between 0.0-0.5ish ohms (closed contact) and OL (open circuit, any HIGH ohm reading should do)...
if this doesn't happen then relay is shagged and needs replacement. It also indicates large short to earth on spotlight circuit - hense 70A fuse blowing!!!
Solution 2: correct earth fault, replace relay - everything should now work!!!
Please remember that even though the relay 'clicks' it doesn't mean that it is working!!!
I hope that isn't too much there guys, I don't think I could have simplified it further or shortened it. I'm sorry if I have over simplied or repeated something someone else has already covered.
Matt
I've been following this for a little bit and it seems to me that there are 3 tests that have not been mentioned???
I've listed them below and tried to give the best layman's description as possible, please be safe when working on life systems regardless of voltage!
To blow a 70A fuse from a set of spotties is unlikely - I would suspect earth fault within one or both of the spotlights!!!
Secondly, most of those standard relays are only rated for say 35A to 40A. So with a 70A short circuit current or greater, I'd suspect the relay is shagged!!!
As an electrician - the faults and symptoms describe indicate to me that the spotlight wiring is shorted, most probably inside spotlight due to water dunking, this and overloaded a 70A fuse and as such destroyed the relay. Inturn, it may have burned a wire somewhere. Listsed below is what I would do!
Check 1 - For presence of earth fault
1. Disconnect positive of spotlights from relay, pin 87.
2. Disconnect negative of spotlights from body earth.
3. use multimeter and test ohms from positive wire to body earth
4. use multimeter and test ohms from negative wire to body earth
if either of these result in anything but an OL (overload - very high ohm reading) then you have earth fault either internal to a spotlight or within the spotlight wiring.
Do not proceed to check 2, the fault needs to be found and fixed before check two, otherwise will only result in more blown fuses
Check 2 - Spotlight globes functioning
1. Reconnect the negative wire from spotlights to earth, preferrable direct to battery (this being better wiring practice).
2. Disconnect spotlight supply wire from pin 30 of relay.
3. connect positive to spotlight directly to supply wire.
this will enliminate your relay from the circuit and allow only the spotties to be checked. if the fuse blows you have a fault in the spotlights or wiring.
if the fuse doesn't blow and the spotlights don't work - loose wiring, busted globes and or bad connections.
if the fuse doesn't blow and the spotties come on then its most probably the relay (see check 3).
Check 3 - Correct Relay Operation
1. Disconnect wires from pins 30 and 87 on relay.
2. Connect multimeter leads to relay. 1 lead to 30 and the other lead to 87.
3. set multimeter to ohms
4. activate relay and deactive
5. multimeter should alternate between 0.0-0.5ish ohms (closed contact) and OL (open circuit, any HIGH ohm reading should do)...
if this doesn't happen then relay is shagged and needs replacement. It also indicates large short to earth on spotlight circuit - hense 70A fuse blowing!!!
Solution 2: correct earth fault, replace relay - everything should now work!!!
Please remember that even though the relay 'clicks' it doesn't mean that it is working!!!
I hope that isn't too much there guys, I don't think I could have simplified it further or shortened it. I'm sorry if I have over simplied or repeated something someone else has already covered.
Matt
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