Burning smell, fans wont turn off

[Riley88]

Hi all, I was out to sea but a friend of mine has been babysitting myc ar for me. he had a weird issue which he told me about and tomorrow i am going to investigate. he took the car for a drive when they smelled a burning smell, upon leaving the car it was noted the smell was mainly inside the car. So i am ammusing it will be a relay. I have BitSynmasters fan fail, rpm and fan relay installed. Also later that day he went outside and noticed the cars fans were still on up front. I have the newest fuse box installed, and tobys fans as well. Any ideas or thoughts of what this could be before i head on over and check it out? In the fan relay i have 2x 10 amp fuses installed by the way, just looking for some pointers before i get into it, thank you!

[David T]

Hi all, I was out to sea but a friend of mine has been babysitting myc ar for me. he had a weird issue which he told me about and tomorrow i am going to investigate. he took the car for a drive when they smelled a burning smell, upon leaving the car it was noted the smell was mainly inside the car. So i am ammusing it will be a relay. I have BitSynmasters fan fail, rpm and fan relay installed. Also later that day he went outside and noticed the cars fans were still on up front. I have the newest fuse box installed, and tobys fans as well. Any ideas or thoughts of what this could be before i head on over and check it out? In the fan relay i have 2x 10 amp fuses installed by the way, just looking for some pointers before i get into it, thank you!

Once you get a look at the relay and fusebox area the problem should be easy to spot. If the fans did not stop the battery will probably be dead.

[Bitsyncmaster]

There are a few owners having this problem. I was planning on finding the problem this Saturday at a tech session with one of those owners. I am not sure if I can get to that tech session because of a death in the family.

What I suspect is that noise from the AC compressor clutch turning off is glitching my solid state fan relay. The problem with that kind of noise all depends on the harness wires, which wires are running close to that noise and for how long is what determines how much noise is seen elsewhere. I never saw the problem with my fan relay but did see the problem with my one off battery relay micro.

I would guess your burning smell may be caused by running 10 amp fuses in the fan fail. All fuses have a resistance to produce the heat needed to melt the fuse link. Lower amp rated fuses have more resistance than a fuse rated for higher amperage. Hence, your 10 amp fuse running about 8 amps (Toby fans) are going to run pretty hot. I did testing of fuses in the fan fail and a fan short circuited just to verify if there was enough power to blow the fuses. I even tested with 30 amp fuses and they all blew open very quickly with a short circuit on the fan connector up near the radiator. So my suggestion is to use 20 amp fuses just to keep the heat down on the fuses themselves.

[Riley88]

I will find out tonight and give an update thank you! I knew I should have put higher amperage fuses I just haven't had time due to my schedule

[jawn101]

Dave, what amperage fuses shipped with the fan fail relay? I am away from the car right now and can't check. I remember they were blue... do we need to pull those and replace with 20s?

[Bitsyncmaster]

Dave, what amperage fuses shipped with the fan fail relay? I am away from the car right now and can't check. I remember they were blue... do we need to pull those and replace with 20s?

I was shipping blue 15 amp fuses if you stated you were using low power fans. But after all my fuse testing, I recommend we all stick with yellow 20 amp fuses. With low power fans you really are not pushing the heat from 15 amp fuses and the fan fail unit anyway. The fuse is really just to protect from a short circuit and prevent a fire.

[Riley88]

Yep, source of the problem, my solid state fan relay opened up , a black liquid had poured out. The fuse box is clean. Dave i have a question. I wasnt sure and i wanted to ask you. Since i have both fan fail and fan relays , when i turn on ac on or when my fans come on, the FAN FAIL light comes on on my ac panel every time, is this normal? I verified the fuses btw both 15 amp those were fine my brown fan relay like...had black ooze that had come out of inside of it. When i get back to my car i will upload a photo .

[Bitsyncmaster]

Yep, source of the problem, my solid state fan relay opened up , a black liquid had poured out. The fuse box is clean. Dave i have a question. I wasnt sure and i wanted to ask you. Since i have both fan fail and fan relays , when i turn on ac on or when my fans come on, the FAN FAIL light comes on on my ac panel every time, is this normal? I verified the fuses btw both 15 amp those were fine my brown fan relay like...had black ooze that had come out of inside of it. When i get back to my car i will upload a photo .

For the fan relay to overheat, one or more of the following is the problem.

I assume the fan relay was working before. If so that eliminates the possibility that power and load pins are reversed.

A bad ground on the fan relay socket will cause the fan relay to overheat. I'm making a circuit change on all new circuit boards to prevent overheating with a bad ground but the bad ground should be fixed. It's the relay ground wires that crimped two wire into each pin that cause the problem. When those crimps age, they get bad connections. I found this on my car and other owners have found the same. Hence my "front relay ground buss" product.

Of course a very high load current but even with 15 amps on each fan that should not overheat the fan relay.

So I need to send you a front relay ground buss and a new fan relay.

[Riley88]

Thank you so much. You are a HUGE help to this community and you have the best customer service I have ever seen. Hands down!