FUSES A BLOWNING HELP

[WILLYSMB]

I recently had a electric problem that almost became a serious problem. smoke coming from the dash and rear light panel a nice electrical smell too the truck. by the way I have 1972 Series III that was restored but I think they forget the wiring. Are 35 amp fuses standard? or are there special 35amp fuses. Anyhow driving along smell smoke stop the engine cuts out, fuses # 1 & 2 fryed and 5 & 6 toast. is this a short or something else, need help and opinions on what it could be. I am the point of replacing all the wire harnesses to avoid a future fire. it took me a box of fuses to get home, each time the engine cut out, had to wait for wires too cool, then replace fuses. this lasted a few blocks then it cut out again. I am not great with electric stuff, should I replace all the wiring and start fresh..... thanks

[Daurie]

Since you have to stop to let the wires cool I would trace the wire or wires that are getting hot and see what you find. If the wires are getting that hot you may have something over fused or a short on an unfused circuit. I believe the Ignition switch/ignition system, horn, headlights, Aux 12v socket and I'm missing something.. are not fused. If the engine cuts out it may be a short in the coil or an ignition switch issue.

If I'm not mistaken there should be only one 35 amp fuse. In most cases you want to make sure the fuse rating is no more than the maximum ampacity of the wire it protects.

Typically
#10 is good for 30 amps
#12 good for 20 amps
#14 good for 15 amps
#16 good for 10 amps
#18 good for 8 amps

Electrical issues can be a real headache. If you can catch them early you can head off really big headaches when the offending wire takes its toll on the wires it's bundled with.

HERE You can download the manual if you dont already have it and the electrical schematic in there should help tremendously. Good Luck!!

[thixon]

Start by tracing the wires that got hot, and everything on the circuits you had issues with. Make sure you are'nt running too many things on each circuit. You're really lucky you did'nt burn your truck up (literally).

A common cause for something like this is a short caused by a wire that's been wiggling around against metal. Finally, the insulation on the wire wears through, and a short results. This can happen in bundles of wires that are not proberly tied up, or through the bulkhead when a rubber grommet is not used.

It sounds like you were lucky. Don't drive it again till you get it sorted out. If you question the job that was done when the truck was restored, or it looks like they half-#ssed it, then replace with a new harness. Its not hard on a rover, and you'll force yourself to learn more about automotive electronics.

Now you know why most of us keep fire extinquishers in our rides!

[greenmeanie]

If I'm not mistaken there should be only one 35 amp fuse. In most cases you want to make sure the fuse rating is no more than the maximum ampacity of the wire it protects.

If you can catch them early you can head off really big headaches when the offending wire takes its toll on the wires it's bundled with.

The above advice can save you a lot of, time, money and possibly even your truck. I recently burnt up the wiringharness on my 101 because the company I bought it from back in the day had taken a short cut and installed all 35A fuses. This was all great until I got a short in one circuit and the fuse didn't blow. Fortunately I was able to get home by recognising the offending circuit by the insulation melting off the wire and pull a connector to break the connection. In the couple of seconds it took to do this the wire melted its own insulation and took out the wire bundle under the dash and also the harness that runs down the length of the chassis.

My advice is that having had a short you should inspect your harness VERY carefully. If it let out the smoke then something got very hot. You can find yourself chasing electrical problems all over the truck after this.

In this case the repalcement harness for the truck is a. Rare b. super expensive c. the same LUCAS crappy design that was there before. On my 101 I had to do a complete rewire so ended up buying a Painless wiring harness and some relay blocks to do the job properly. Now I have 12 fused circuits, 7 relays controlling the lights and fuel pump, dual battery controller with manual selector and the whole lot located somewhere a lot more mechanic friendly than the driver's footwell. To make life easier down the road I made up a new wiring diagram first which makes installation and any fault finding a lot more simple. This travels with the truck to prevent SPO accusations There are more options out there than LUCAS if you don'y mind the authneticity bit.

Cheers
Gregor

[friar mike]

let me tell you my horror story. I changed all the wiring in a bugeye sprite got to the last marker light hooked it up backwords and poof a whole main harness gone. this car was pos earth and I made a booboo by hooking up the LAST light neg earth so as I ordered on my dime (not the customers) a new harness I told the owner I was not going to install this one without a fuse kit you see the old brit cars and trucks had from no fuses to two fuses and thats not enuff to do the job right. My 1980 109 is way under fused also.

[Daurie]

Some good insurance would be to put a 30 or so amp fuse on the brown wire coming off the positive terminal block at the starter solenoid. Now that I think about it, next time I'm in the shop working on my truck I'm going to turn on all my accessories and put my amp meter on that unfused brown wire thats always on my mind!

[friar mike]

That is a good idea and I know of guys who do that but it will do nothing for most of the small circuits thay will still fry.

[greenmeanie]

At the risk of sounding like a Painless advert this is a piece of kit specifically designed for the job and well worth the money.

http://www.painlessperformance.com/webcatalog/largeview.php?SearchField=80101

They also sell after market fuse blocks of various sizes that can be spliced into the existing system if that works for you.

Cheers
Gregor

[Daurie]

That is a good idea and I know of guys who do that but it will do nothing for most of the small circuits thay will still fry.

Yeah... but it will make me feel better! LOL. I don't see where it would be too much trouble to get a few inline fuse holders and do the lights and smaller bits that are not fused. I'll have another look at the schematic....

I was actually going to do a little experiment with some #18 wire, an amp meter, a battery and some resistors...

[friar mike]

Yeah... but it will make me feel better! LOL. I don't see where it would be too much trouble to get a few inline fuse holders and do the lights and smaller bits that are not fused. I'll have another look at the schematic....

I was actually going to do a little experiment with some #18 wire, an amp meter, a battery and some resistors...

The piece of kit that Moss sold me for the bugeye was some inlines that pluged in where the main harness plugs in at the fire wall thay just plug in no mods to the wiring at all.Thay work out very nice I got extra ones for later use.

[thixon]

Gregor gave you some excellent advice. The Painless harness and fuse block is the way to go. I did'nt throw it out there earlier, and probably should have. I've put several in jeeps, and other brit cars. When I finally get to the electrical stage on my IIA (its still in peices), that's exactly what I plan on doing. There is no way I'd go back to the stock setup. Throw down the cash, and knock it out. It not hard, and you'll get to know the truck that much better.

Good luck!

[jp-]

Some good insurance would be to put a 30 or so amp fuse on the brown wire coming off the positive terminal block at the starter solenoid. Now that I think about it, next time I'm in the shop working on my truck I'm going to turn on all my accessories and put my amp meter on that unfused brown wire thats always on my mind!

I did that on my 88!

I didn't want to remove the ammeter, but didn't want all the power going to it from the alternator (which would keep it pegged). So, I routed the incoming brown wire to the ammeter and the other side to the ignition switch. Of course, all it tells me is how much current is flowing through the ignition switch, but it's still neat to watch it work.

[Jeff Aronson]

Like everyone has said, you have a serious short, possibly a dead short in the alternator. Something is sending a lot of current back through your fused wiring and you risking a serious fire - or you have a wiring that is grounding out and causing the same problem.

I once had my II-A halted by the meltdown of engine wiring. I replaced that part of the wiring harness with the correct Rover item. Despite the fact that at the time I felt I knew nothing about Rover wiring, the job was done by me in a snowbank and the car was on the road that afternoon.

I'd stick with the original harness if possible.

Jeff

[greenmeanie]

I'd stick with the original harness if possible.

Jeff

Fuses, fuses at least add some fuses! Splice em in, put em in a box or whatever paddles your canoe but you can never have too much protection.

It does also seem to be common wisdom that easy upgrades to your electrical system include relays to control power to the headlights and preferrably the horn too. Brighter headlights are something every Series Rover needs and reducing the feeder losses helps lots. IIRC a 1V drop leads to only 70% of optimum brightness.

I'm a firm believer that when forced to dig deep with repairs that any upgrades should be incorporated too.

Cheers
Gregor