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#1 1969 E Type Series 2 fuses are smoking hot

Posted: Tue Dec 04, 2018 10:05 pm
by CGloss
Hello, I am new to this forum. I have a 1969 Type E 2+2 4.2L that has been restored . The car sat for several years after restoration. I have managed to get it running with all the lights, flashers, wipers, and even the horn working. While test driving today i noticed some smoke coming from behind the instrument cluster. After inspecting on the side of the road I decided to head back to the shop. From what I can tell, fuse #6 is getting hot enough to melt the insulation around the terminal end. I am hoping for some advise on what to do next. Thank you in advance.

#2 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Tue Dec 04, 2018 11:24 pm
by Tbob
My first guess would be a dirty fuse holder and connector. Clean with a wire brush and contact cleaner. Squeeze it together to ensure good contact.

#3 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Tue Dec 04, 2018 11:29 pm
by abowie
Fuses 6 and 7 supply power via green wires.

Originally on an S1 car 6 would supply horn relay, screen washer, fan relay, stop lamp switch. 7 would supply wiper motor, reverse lamp, fuel and choke light and the indicator, plus the 10V regulated supply to the instruments.

Note that S2 cars might be different; I don't have wiring diagrams for them.

With your car there are a couple of possibilities. It may be that one of the devices attached is faulty and drawing excess current. It may be that green wires have been incorrectly moved between 6 and 7 over the years resulting in more current being pulled through one fuse than is correct. It may be that the fuse you have fitted is incorrect in rating or damaged. Finally if you have replaced your fuse blocks with new reproduction ones it has been my experience that the plastic in the repros is softer and I have had them melt and fail.

#4 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Dec 05, 2018 2:41 pm
by CGloss
Thank you for your help. I was thinking that possibly the cooling fans might be the issue due to the driver side fan not working. After replacing it, the problem has not changed. There is a brown fused wire also going to my fuse #6. Would it be a problem if I ran an additional fused link from the battery directly to that brown wire in hope of relieving some of the load from fuse #6? Thank you in advance for your time and knowledge.

#5 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Dec 05, 2018 4:33 pm
by Bfastr
Fuse #6 is a busy fuse in the Series 2. your best bet is to find the schematic at learn what should be coming off that fuse, yes you could isolate things like the fans and run a fused wire just for them, but fans shouldnt be running all the time, so I doubt thats the trouble, and if the in-op fan was shorted the fuse would blow.

as mentioned, clean the contacts and make sure thats not the problem, the fuse will be hot under normal load and thats ok, but it shouldn't melt anything or smoke.

here is a picture of my S2 right side fuse block, maybe it will give you an idea of what should be there.

Bob F
Image

#6 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Dec 05, 2018 4:54 pm
by cactusman
As others have said it may be dirty connections. Failing that there is an excess load somewhere. I would not recommend adding an extra wire. Fuse six is ignition live and feeds the horn relay, the heater motor, the engine cooling fans, the screen washer and the brake lights. This assumes your car is wired as the factory intended. Wires on one side of the fuse will be white (supply side) and green (load side). If you have air con then it also feeds part of that too. Assuming all is clean then one of these loads is faulty....I would suspect the engine cooling fans. It needs to be resolved as electrical fires can be catastrophic

#7 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Dec 05, 2018 5:26 pm
by Heuer
Wiring diagrams are in the Forum Knowledge Base - here you go:

S2 Colour Wiring Diagram (by Bill Molloy): https://www.dropbox.com/s/dx7f9jvz6pvca ... r.jpg?dl=1
S2 harness layout: https://www.dropbox.com/s/djyleznlp0qyl ... m.jpg?dl=1
S2 Dash wiring: https://www.dropbox.com/s/8i1ljkfu1wkl7 ... g.JPG?dl=1

#8 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Dec 05, 2018 5:26 pm
by Heuer
Wiring diagrams are in the Forum Knowledge Base - here you go:

S2 Colour Wiring Diagram (by Bill Molloy): https://www.dropbox.com/s/dx7f9jvz6pvca ... r.jpg?dl=1
S2 harness layout: https://www.dropbox.com/s/djyleznlp0qyl ... m.jpg?dl=1
S2 Dash wiring: https://www.dropbox.com/s/8i1ljkfu1wkl7 ... g.JPG?dl=1

#9 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Dec 05, 2018 8:30 pm
by CGloss
i would like to thank all of you who responded to my post. Ya'll have been extremely helpful to me in figuring out this electrical issue. It very well might be the cooling fans. It seems that the a/c blower motor is also running off the #6 fuse. After unplugging the a/c there have been no more problems with the fuse smoking. Although, I have replaced the driver side cooling fan with a rebuilt unit. It seems to be working fine, but I have noticed that the rebuilt fan motor doesn't always come on when it is supposed to. I am under the impression that the a/c was added on as an aftermarket addition. From looking at the wiring diagrams, I have noticed there is only 1 fan relay for both fans. Could this be the overload I am looking for?

#10 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Dec 05, 2018 10:44 pm
by Tom W
There’s one relay that switched both cooling fans, triggered by the otter switch in the radiator. If your car has factory AC, there should be a 2nd really that turns the fans on when the AC’s on, irrespective of the radiator temperature.

#11 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Sun Dec 09, 2018 3:21 pm
by Jage70
Hi CG, I have an 1970 SII "E" OTS that I completely rebuilt from boxes up!! The circuits fed by fuse #6 are numerous .Your only option, after ensuring that all the contacts on the fuse panel are clean, is then to check out each of the electrical items that are on that particular fuse. The items on this circuit are : screen wiper motor and switch : screen washer : all the dash gauges for battery ( voltage) , oil pressure , coolant temp , and fuel gauge ) : stop lamps : heater motor : all lighting flasher circuits : coolant fan relays and the circuits.
When i first realized this some years ago I was very concerned about the potentially high load this circuit might be expected to handle!!! The first thing I did was to feed power by an N wire ( fused ) directly to the coolant fans. This meant that the fans would run on when the ignition was switched off off, and they would stop only when the Otter switch "said so" !
Even having done that , it was also noted that both fuses 6 and 7 are fed by the W wire from the ignition switch. Having R&Red that switch, I felt that the potential combined load from fuses 6and 7 could cause heating issues for it. I now have a power relay activated by the ignition switch W send switched power via a fused N line to feed the relay. Now the power to fuses 6&7 bypasses the ignition switch. In addition , the power for heating the rear window ( if you have one ! ) comes via the power relay and not through the ignition switch!!
While studying the 6/7 fuse circuits, it was clear that the W feed to the ignition and fuel pumpwas not fused..so now an in line fuse is fitted.
So this is probably a lot more than you felt you should know, but please ponder on it at least from a safety view point.Regards, John H, ON Canada.

#12 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Oct 13, 2021 10:46 pm
by Mondy
Bfastr wrote:
Wed Dec 05, 2018 4:33 pm
Fuse #6 is a busy fuse in the Series 2. your best bet is to find the schematic at learn what should be coming off that fuse, yes you could isolate things like the fans and run a fused wire just for them, but fans shouldnt be running all the time, so I doubt thats the trouble, and if the in-op fan was shorted the fuse would blow.

as mentioned, clean the contacts and make sure thats not the problem, the fuse will be hot under normal load and thats ok, but it shouldn't melt anything or smoke.

here is a picture of my S2 right side fuse block, maybe it will give you an idea of what should be there.

Bob F
Image
Hi Bob, I can't add pics yet, but hoping you can help. Please look at that pinkish wire with the black bands connected to the top most right fuse tab. There is a similar wire coming out of the same harness that disappears to the left behind the hose for the air vent.

Would you mind terribly telling me where that connects and what it's for?

I don't know if I knocked it out or it just wasn't hooked in properly and I can't figure out where it goes!

I'm in the middle of a project and have the battery unhooked and need to figure this out before I reassemble everything.

#13 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Oct 13, 2021 11:05 pm
by abowie
Red black is lighting switch.

See posts #7 and #8 for wiring diagrams.

#14 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Wed Oct 13, 2021 11:06 pm
by johnetype
The "pinkish wire with black bands" (originally red with black bands) comes from the sidelight switch (the leftmost of the double rocker light switch) and goes on via fuse 5 to feed the sidelight circuit (the red wire) which is all the sidelight and panel lights feed.

#15 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Thu Oct 14, 2021 6:26 pm
by MarekH
More than one person has said "It could be dirty connections".

Well no it can't be. When you have dirty connections, you increase the resistance in the circuit. A high resistance circuit draws less current than a low resistance circuit. Smoke and melting were reported. That's due to a very high current flowing. The reason a high current flows is because there is a very low resistance in the circuit.

To isolate which circuit is low resistance, you can diagnose it one of two ways.

1/ With the battery disconnected, measure the resistance to earth of each circuit that fuse serves. To do that, disconnect all spades from the fuse block and measure the resistance to earth of each one of the components being served, one at a time, by putting one probe on the component wire's spade and the other on the chassis with the meter on a low resistance setting. The component still has to be switched "on" to test it, even though the battery is disconnected. One (or more) of them will read close to zero ohms. There is your culprit.

2/ With the battery connected, remove the fuse and all of the spades serving the multiple circuits. Put the meter on "amps" (the high amps setting) and serially check each circuit's current draw by turning on the circuit component. (The meter probes replace the fuse.) One (or more) of them will be very high, e.g. probably in excess of 10 amps. That's your culprit.

It is always possible that there is a near short circuit between the loom and the chassis. This would also draw a high current and would be diagnosed the same way.



"Can a relay cause this problem".

No, that's unlikely. A relay usually solves a problem like this. Typically they are used when the car designer decides that a high current is being pulled (e.g. a fan or the horns), so rather than lump it with lots of other circuits, we'll give it its own dedicated switchable power supply. That way, only the relay current is drawn through the fuseboard fuse and the high current is usually fused through its own circuit.


The sensible owner will do 2/ even if they do not have a problem. Write down the answers for all of the circuits and then fit a more appropriate (lower rated) fuse (rather than a blanket 35 amp fuse). You also have a handy record for the future for troubleshooting.

kind regards
Marek

#16 Re: 1969 E Type Series 2 fuses are smoking hot

Posted: Fri Oct 15, 2021 7:45 am
by ALAN COCHRANE
No one has yet mentioned the possibility of a bad connection between the cable and spade terminal. I had this issue with one of the unfused brown wires which would intermittently produce white smoke on start up.
At first this was only visible through the left hand middle dashboard vent.
When I eventually diagnosed the problem the wire was only hanging by a few strands.
Luckily there was enough spare length to re-terminate it onto a new spade connector.
Worth checking since initially there was nothing visible in my case.