While posting about another fuse issue, my friend Dieter suggests to me to upgrade MGF fan fuses to 20amps. The original issue I posted about was a problem with the 30amp fuse 7 blowing (or fuse 1 depending on which manual you read). While showing pictures of the under bonnet fuses Dieter could see I still had the original 15 amp fuses in place.
Dieter has his own website which is massive store of MGF information. On this issue specifically he has notes in the parts reference numbers section, https://www.mgfcar.de/epc/1445.htm. I thought I’d add this information also with some pictures and details from the Technical Bulletin issued by MG Rover.
Quick Answer #
If your MGF is still using blue 15 amp fuses for the aircon and radiator cooling fans, you will want to upgrade to yellow 20 amp fuses. These are in the under bonnet fuse block. Specifically fuse number 6 (radiator fan) and fuse 5 (condenser fan). There seems to be come confusion over the numbering of these fuses across workshop and owners manuals. So, for the sake of clarity, if looking to the rear of the car from the front, they are the 2nd from he right and 3rd from the right. You can also use the notes on the fuse box cover. Just align the cover with the various fuses using the different fuse ratings and colours of the fuses to be sure.
The images above show the change. Note there is a manual reset 30 amp fuse in position 1 (or position 7 per owners manual). This is because I was still troubleshooting this fuse blowing after starting the car.
Background #
It turns out that MG Rover identified an issue with the fuse amperage for the radiator fan. On 26 October 2001 they issued Technical Bulletin (TB) 0046. This noted that the radiator cooling fan had failed due to the blowing of the 15 amp fuse 6 in the under bonnet fuse block. It seems that the current draw from the fan would vary and could exceed 15 amps causing the fuse to blow. With this fuse blown, and the driver likely unaware, this may cause engine over heating.
The TB suggests to replace fuse 6 with a 20 amp yellow fuse. It also notes that this creates no risk for the systems the fuse is protecting.
My friend Dieter also noted to change fuse 5 as well. Fuse 5 protects the condenser fan. Seems logical, that fan might similarly blow a 15 amp fuse. Although, the loss of the Aircon wouldn’t impact the car’s operation, the passengers would likely want to keep it working.
Technical Bulletin 0046 #
So, here is the Technical Bulletin that was published giving the reason to upgrade MGF fan fuses to 20amps.
Manual Reset Fuses #
While on the topic of fuse issues, I thought a quick mention of manual reset fuses would be helpful. I didn’t know of these or have these when dealing with my first electrical issue. That is the brake light and reverse issue I had. However, I got some when diagnosing the issue of the 30 amp fuse blowing after my car was running. I’m sure there are plenty of options. The picture is the set I got on Amazon. They are very helpful for diagnosis of fuse blowing problems.
Other Materials #
I’ve built this website and spent time on the knowledge base to bring together a lot of information I have collected from around the internet. The intent is making it easy to find rather than having to know about and have skills with search engine query terms to get what you were looking for. Please make use of the knowledge base.