I love the smell of burnt plastic in the evening

[? ? ? ?]

Driving the DeLorean home from work Friday night, A/C running, I'm sitting at a red light a mile from home, and I start to smell something burning. I look over to my passenger side, and see an unhealthy amount of smoke coming from somewhere behind the passenger seat. At this point I think the car's on fire, so I kill the A/C and turn the car off, preparing for the worst as I pop the engine cover. Thankfully, I see nothing, no smoke, no fire, everything looks fine back there. Go back into the cabin though and smoke is still coming out from behind the passenger seat, and I start to smell burnt plastic. At this point I realize if must be coming from the relay compartment. After about a 5 minute wait, the smoke starts to clear up, start the car up, and make it home.

Open up the relay compartment and sure enough, discover the fan fail fused jumper wire has melted. The other relays looked fine and nothing else appears to have burned or melted.

Couple questions
1) I've never heard of this fused wire melting to the point of generating so much smoke before, is that known to happen with it?
2) Is the wire melting like this a sign that my fans might be on their way out? The car still has the original fans from what I know, and I've never previously had any overheating issues or problems with them.


Probably time for me to order Dave's solid state fan fail unit

[CFI]

Driving the DeLorean home from work Friday night, A/C running, I'm sitting at a red light a mile from home, and I start to smell something burning. I look over to my passenger side, and see an unhealthy amount of smoke coming from somewhere behind the passenger seat. At this point I think the car's on fire, so I kill the A/C and turn the car off, preparing for the worst as I pop the engine cover. Thankfully, I see nothing, no smoke, no fire, everything looks fine back there. Go back into the cabin though and smoke is still coming out from behind the passenger seat, and I start to smell burnt plastic. At this point I realize if must be coming from the relay compartment. After about a 5 minute wait, the smoke starts to clear up, start the car up, and make it home.

Open up the relay compartment and sure enough, discover the fan fail fused jumper wire has melted. The other relays looked fine and nothing else appears to have burned or melted.

Couple questions
1) I've never heard of this fused wire melting to the point of generating so much smoke before, is that known to happen with it?
2) Is the wire melting like this a sign that my fans might be on their way out? The car still has the original fans from what I know, and I've never previously had any overheating issues or problems with them.


Probably time for me to order Dave's solid state fan fail unit

The fused jumper was meant to be a temporary fix. Unfortunately DMC went under before they came up with a permanent solution. At some point it will fail (as you’ve seen). Dave’s solid state unit is a good idea. While you’re in there, you should replace some of the other relays that are known to generate excess heat:
RPM relay, Lambda relay, radiator fan relay.

[Jonathan]

If you remove that fused jumper entirely, what do the ends of the spade connectors look like? The reason I ask is I had one of those in my car and noticed a little melty melty, but caught it sooner than your burnt plastic and smoke scenario. The male spade connectors were tarnished and to me it looked like the entire current was going over just a small portion of the metal surface and on into the wire and fuse holders.

I have the original fans too and never had any overheating issues. I've got my eye on new fans though, but not sure if I would do anything differently with the fused jumper contraption. I replaced it after I saw that discoloration and will do again if it reappears. I have gotten into the habit of checking these kinds of electrical things in the Spring each year before the season starts. Just looking for wear and tear and possible problems. Hoping to catch them before it gets costly.

[Bitsyncmaster]

Common problem if your still running OEM fans. Of course the 30 amp draw is the main cause but it' probably because the fan fail socket pins are not clamping tight enough on the jumper pins. One of my friends jumpers actually caught fire.

You probably will need a new socket and five new pins to crimp on the existing wires. You probably can not pull the old pins from the melted socket.

[? ? ? ?]

If you remove that fused jumper entirely, what do the ends of the spade connectors look like? The reason I ask is I had one of those in my car and noticed a little melty melty, but caught it sooner than your burnt plastic and smoke scenario. The male spade connectors were tarnished and to me it looked like the entire current was going over just a small portion of the metal surface and on into the wire and fuse holders.


They don't appear too bad. Appears to be some slight melting along the one side though.

[? ? ? ?]

Common problem if your still running OEM fans. Of course the 30 amp draw is the main cause but it' probably because the fan fail socket pins are not clamping tight enough on the jumper pins. One of my friends jumpers actually caught fire.

You probably will need a new socket and five new pins to crimp on the existing wires. You probably can not pull the old pins from the melted socket.

So thankfully, I didn't have any issues disconnecting the jumper from the socket. From what I can tell, the existing socket doesn't appear to have been ruined. I don't see any clear signs of melting or burns there. I'm hoping I got lucky and only the jumper was ruined.

[Bitsyncmaster]

You got lucky. Your problem was BUSS brand fuses. I ran testing of them and they will melt running near the rating of the fuse. Your fan fail socket does look good in the photo.

Make sure you use LITTELFUSE brand fuses.

I recommend all owners not run OEM fans.

[Ras12]

...I recommend all owners not run OEM fans.

Dave, based on wt you have heard from other owners and your own experience which fans do you recommend?

[84Impulse]

Driving the DeLorean home from work Friday night, A/C running, I'm sitting at a red light a mile from home, and I start to smell something burning. I look over to my passenger side, and see an unhealthy amount of smoke coming from somewhere behind the passenger seat. At this point I think the car's on fire, so I kill the A/C and turn the car off, preparing for the worst as I pop the engine cover. Thankfully, I see nothing, no smoke, no fire, everything looks fine back there. Go back into the cabin though and smoke is still coming out from behind the passenger seat, and I start to smell burnt plastic. At this point I realize if must be coming from the relay compartment. After about a 5 minute wait, the smoke starts to clear up, start the car up, and make it home.

Open up the relay compartment and sure enough, discover the fan fail fused jumper wire has melted. The other relays looked fine and nothing else appears to have burned or melted.

Couple questions
1) I've never heard of this fused wire melting to the point of generating so much smoke before, is that known to happen with it?
2) Is the wire melting like this a sign that my fans might be on their way out? The car still has the original fans from what I know, and I've never previously had any overheating issues or problems with them.


Probably time for me to order Dave's solid state fan fail unit

Glad it wasn't catastrophic!

[Bitsyncmaster]

Dave, based on wt you have heard from other owners and your own experience which fans do you recommend?

I've not heard any complaints from any of the vendors fans. I have Toby fans in my car which fit in the OEM fan shroud.

[CFI]

I've not heard any complaints from any of the vendors fans. I have Toby fans in my car which fit in the OEM fan shroud.

I love my Toby fans. I highly recommended them.

[DMC-Ron]

I love my Toby fans. I highly recommended them.

Same here. Toby's fans have been great.

[ssdelorean]

I love my Toby fans. I highly recommended them.


Same here. Toby's fans have been great.

Ditto here. Toby fans have been great. Great service too. After YEARS of daily use, one of my fan motors died. Toby had manufacturer replace under warranty.

[? ? ? ?]

I love my Toby fans. I highly recommended them.


Same here. Toby's fans have been great.


Ditto here. Toby fans have been great. Great service too. After YEARS of daily use, one of my fan motors died. Toby had manufacturer replace under warranty.

Checked his website, and it looks like Toby's fans are currently sold out unfortunately. I'm planning to take the car in to Danny at DMCCA in July, so I'll probably just end up replacing the fans with DMCH's replacements at that time. Ordered Dave's fan fail unit in the meantime.

[MrChocky]

So, what we're saying here is that we're a huge Toby fan.

[DMC-81]

Defective fuses and a temporary Y jumper fix aside: I know we are going against the grain, but here in Florida where we drive all year in a hot climate with the A/C on almost constantly, some of us have rebuilt/refurbished our OEM fans AND run them through separate dedicated relays, one for each fan, together with a more direct power feed. We still incorporate Dave's awesome fan fail unit as source of activation. My car is finishing it's second year in successful testing.

Based on experience, my opinion is there is nothing wrong with an OEM fan (caveat: unit in good condition, and grounded properly). The flaw is that the car's wiring is not up to the task in feeding the power to them. On the Fan Fail socket, all the power is sourced from one connector (pin 87, i.e. the combined wire on the Y jumper). This is going to two high draw fans. It is akin to connecting a high power tool to a long extension cord.

Your mileage may vary.

[RIUM+]

I had the crimp on one terminal of my DMCH cooling fan bypass Y-wire go bad. This was in a car with Toby's lower-current fans, with all grounds regularly cleaned, and you can even see in the photo I used conductive carbon grease on the spades to help give a better electrical connection. This isn't the only time I've had a bad crimp in this car, which is a little surprising to me, so I've slowly been soldering every crimp I come across "just in case".

66557

[DMC-81]

I had the crimp on one terminal of my DMCH cooling fan bypass Y-wire go bad. This was in a car with Toby's lower-current fans, with all grounds regularly cleaned, and you can even see in the photo I used conductive carbon grease on the spades to help give a better electrical connection. This isn't the only time I've had a bad crimp in this car, which is a little surprising to me, so I've slowly been soldering every crimp I come across "just in case".

66557

Wow. This is a case in point. That is the combined wire/connection, where as you stated, even with low amp fans and good grounds, this spot is still a concern.

I agree. I recommend soldering the connections on this cooling fan circuit. I also recommend only using the Y jumper on an emergency basis.

[Bitsyncmaster]

Wow. This is a case in point. That is the combined wire/connection, where as you stated, even with low amp fans and good grounds, this spot is still a concern.

I agree. I recommend soldering the connections on this cooling fan circuit. I also recommend only using the Y jumper on an emergency basis.

I don't use insulated crimp terminals on any high power connections. Those just squeeze the barrel onto the wire. I trust the crimps on non-insulated terminals but soldering would be even better. All my battery wires have crimped and soldered terminals.