Auto Reset Automotive Circuit Breakers - 12 volt

[t7389sg]

There are 3 of these circuit breakers in the front of my 91 350 LE right beside the battery isolator. Does anyone know what amperage they should be? I need to replace one and I figure I will just replace all three. I know they are 12V but I'm not sure what amp to order. I think they may be 30 amp but I am not sure. There are no markings on them at all. Thanks for your help. Steve

[idroba]

Are the wires fairly large which go to the CB's? Like #10? If so, 30 amp may be the correct size. If the wires are smaller, like #14 or so, then probably 15 or 20 amp would be what they are. My '83 310 didn't have any self resetting CB's in that area, so this is only a guess on my part.

Do you know what the CB's protect? That also would give you a clue as to the proper size. If they are near the isolator, and connected to it in any way, they could be charge lines to the batteries, and would be 30+ amps I would think.

[t7389sg]

the circuit breaker that has failed protects the air compressor for the rear air bags and that wire is fairly large. I would think a 10 gauge. the 2 other breakers are 14 or 18 I would guess. I will look through the large owner manual for this rig and see if they mention the amperage requirement for these. I may even have the wire diagrams for this coach somewhere. Thank you for your responce

[dznf0g]

All circuit breakers I have seen have, somewhere on them, a stamping or inked spec rating. Usually it is stamped in the metal housing or printed on the bottom (plastic) "board". It will probably require removal to read.

[t7389sg]

I will check again for some markings. These are plastic housing CB and are a little crusty from age. Thank you for weighing in on this. Steve

[wxbuoy]

Steve,

If you can wait till tomorrow afternoon when it is light I will be happy to go out and see if I can see if mine have any markings on them.

[t7389sg]

I looked again at the CB I removed and the only markings on it are AUX and BAT molded in to the top next to the 2 terminals.

[wxbuoy]

Can you attach a picture so I know what exactly I am looking for in the limited daylight when I get home


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[t7389sg]

[Gnorts]

I'm seeing what looks like undercoating on and around the breakers - are they underneath the vehicle? If so, that's a stoopid place to install them; no wonder one has failed.

These thermal resetting breakers are notoriously inaccurate, and these are lookin' pretty bad, with lots of rust on the connectors. They're cheap - replace 'em all, and clean up all the connections, and spray the finished connections with insulating varnish to keep the weather out.

Amperage ratings are probably on the bottoms, so removal of the failed one will be necessary. Be sure to disconnect the battery's ground wire before doing the work.

[t7389sg]

These are located under the front access panel to the engine to the right beside the isolator. I think they are covered in road grime as it wipes right off. Yes the wires are rusty and corroded and maybe a little cooked. My plan is to replace all of them and remake the jumpers and clean everything up. I just need to order the correct CB. They are not expensive but I think I do need to get the amp rating correct. I post here to find out if anyone here has done this before and to find out what did they buy to fix this. There are not any markings on these CB's other than Batt and Aux.

[wxbuoy]

Steve

All mine have 30A on them. So I guess they are just there for power distribution to the sub fuse panels



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[t7389sg]

Wow your wires are a little rusty like mine. I think you're rIght about these feeding the fuse box except the one in the middle. I know that one goes direct to the rear air compressor. When your ready to renew yours I will have the 411 to help you. Thanks again, Dave. Oh and you listing Good Sam as your tow vehicle made me laugh.

[idroba]

On those type of self resetting CB's I have found the rating stenciled on the bottom of the unit, so they may have to be removed to read that (if it is there).

Those terminals are mostly in bad condition, and you definitely should replace them when you do the job. The one short jumper even looks to have overheated with the yellow insulating material deformed.

[wxbuoy]

Steve

I plan on replacing them and cleaning up the connectors this winter. I also going to do the battery isolator as well. Any info on source of supply would be great!




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[Gnorts]

Originally Posted by wxbuoy

Any info on source of supply would be great!

30 amp. In-Line Circuit Breaker - Perpendicular Mount Bracket Pollak Accessories and Parts 38630

[wxbuoy]

Thanks!

[t7389sg]

This is what I ordered from www.delcity.net
I needed 2 with one kind of mounting bracket and 1 with a different type of bracket and I ordered some type of rubber cover for each as well. I will report back how well they fit.

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1 71130 30 Amp Auto Reset Plastic Circuit Breaker$2.14 $2.14
2 72255 30 Amp Auto Reset Plastic Circuit Breaker$2.14 $4.28
3 907201 Stud Mount Circuit Breaker Insulator, Red$0.61800 $1.85
1 DC2015 2015 Del City Catalog (1 MIN) $0.00 $0.00
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Shipping: $7.99
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Total: $16.26





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[wxbuoy]

Great, will wait for your report before proceeding.

I have to locate a compatible isolator in the mean time. Not to mention a whole lotta stuff to do on the inside!


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[Jammer]

I've had good results dealing with delcity.