Fuse Box Replacement

[Ricker]

So, the car wouldn't start. Then it did. Ran once it started. Stopped it and then it didn't. Checked the fuses and fuse number 7 (20 amp - yellow) was completely melted including the fuse box area itself. Forced a new fuse in the slot and it ran perfectly.

Not sure what caused it. Is there a way to check that fuse seat to see if the new fuse box won't end up the same way?

Is there a better fuse box or preferred better supplier? Any suggestions when and how to replace it?

Thanks!

[WHO1DMC]

So, the car wouldn't start. Then it did. Ran once it started. Stopped it and then it didn't. Checked the fuses and fuse number 7 (20 amp - yellow) was completely melted including the fuse box area itself. Forced a new fuse in the slot and it ran perfectly.

Not sure what caused it. Is there a way to check that fuse seat to see if the new fuse box won't end up the same way?

Is there a better fuse box or preferred better supplier? Any suggestions when and how to replace it?

Thanks!

This is very common problem. I've done the replacement myself. Melting is usually caused by corrosion plus there's a lot of current going through that fuse. Don't use the cheap Chinese fuses they tend to create more heat before or even if they blow. Get the one from classic dmc they are made of better plastic. The fuse box is just sets in place so just pull up. Disconnecting the banks of relays from the tray will help dealing with the wires. Replace one connection at a time so you don't get lost. Removing the passenger seat will help with the limited room. The wires are kinda tangled going into the box so untangling will help with slack.





Dave B.

[JohnZ]

Long long ago I installed a special "John Hervey's fuel pump saver kit" that rewires the pump circuit, I wish I could remember how I did it.... anyway it was not a problem anymore, and also I extruded fuse 7 and another couple of fuses from the fuse box (and replaced fuses and fusebox altogether...)

It was a long time ago and unfortunately I don't remember much, and also I can't seem to find material about this "fuel pump saver kit" on the internet... All I remember is that I now have a red wire that goes under the center console and feeds the pump, I wish I could tell you more! :(

[Patrick C]

Long long ago I installed a special "John Hervey's fuel pump saver kit" that rewires the pump circuit, I wish I could remember how I did it.... anyway it was not a problem anymore, and also I extruded fuse 7 and another couple of fuses from the fuse box (and replaced fuses and fusebox altogether...)

It was a long time ago and unfortunately I don't remember much, and also I can't seem to find material about this "fuel pump saver kit" on the internet... All I remember is that I now have a red wire that goes under the center console and feeds the pump, I wish I could tell you more! :(

Looks like it ran a new dedicated 12V switched source to the fuel pump with a circuit breaker added.

https://web.archive.org/web/20161228052320/http://www.specialtauto.com/

https://i.ibb.co/Ndn7KNr1/IMG-0500.jpg

[JohnZ]

It gotta be it! I Remember my fuse number 7 was already melted when I decided to install this kit! The plastic had became one with the fuse box and left a crater in there! I was lucky because I was never left stranded and I was able to save it in time!

So then I put in a new fuse box, new fuses and also extruded a couple of fuses, and I added a little grill on the wooden cover, which is blocked by the carpet anyway, but still! :)

And the Hervey solution was really simple to put on and I never had a problem since!

[dn010]

Long time ago I wired a couple of computer fans into that compartment to promote airflow in there. I feel it has keep things running cooler in there.

[JohnZ]

Long time ago I wired a couple of computer fans into that compartment to promote airflow in there. I feel it has keep things running cooler in there.

That's very interesting! Can you tell me where did you put them and in which orientation in order to maximize air flow?

[Bitsyncmaster]

Looks like it ran a new dedicated 12V switched source to the fuel pump with a circuit breaker added.

https://web.archive.org/web/20161228052320/http://www.specialtauto.com/

https://i.ibb.co/Ndn7KNr1/IMG-0500.jpg

Fuel pumps draw about 6 or 7 amps. That fuse #7 also powers the WUR heater (guess 1 amp) and the lambda ECU and FV (less then 2 amps).

The original fuse block have very low tension pins so any oxidation creates a lot of heat. The "new" DMCH fuse block has very good pins.

[Helirich]

You may want to replace all the relays with Dave?s solid state versions. This eliminates a lot of heat in that area. My fuse box is kind of melted. I did the relays and pulled every fuse, sanded them with scotch brite and reinstalled them. It hasn?t got any worse and I can tell theres less heat in there. I have a new box to install, but it can wait for now.

Might be a good idea to spray the fuses with a good oil to stop corrosion. Maybe some dielectric grease?

[JohnZ]

This thread shows that, more often than not, the solution lies in multiple actions at the same time... Rewire the pump, replace the fuse box, install modern relays, clean fuses, put a fan. Everything helps!

[JETS 81 DMC]

A product called Detoxit d5 is highly recommended on other forums for cleaning corrosion/oxidation and leaving a protective coating for fuse box terminals.

I have used it and find it an excellent product. I have also used it on electronic switches and controls.

https://thedeoxit.com/#Hosa-D5S

[Ricker]

From what I can understand the "melting" is due to corrosion not a circuit overload. I've ordered a new fuse box that includes fuses and the connectors. I think I will delay on the rest of the suggestions although they all make sense. This will give me a chance to do it all over again. lol

[Helirich]

This thread shows that, more often than not, the solution lies in multiple actions at the same time... Rewire the pump, replace the fuse box, install modern relays, clean fuses, put a fan. Everything helps!

Also, might want to change the lights out for LEDs. Anything to get less power going through there.

[Ricker]

Already changed a while ago to LEDs. Years ago, changed out the radiator fans. Now have the actuators for the door locks. Sometime ago replaced all the relays with new upgraded ones. Thought I did all the electrical loads reductions. Didn't even think or know about the fuses till now. Thanks Lucas Electrics.