Wiring Gremlins

[MJH2454]

Hi Guys, got what on the face of it is an odd one, Triumph Spitfire MKIV no side lights, no fuel or water temp gauge reading, no brake lights. no horn and no indicators, however I do have head lights both beams but no headlamp flash mode, I also have wipers and heater motor.

According to Hanes the top fuse not only controls the Heater and Wipers which I have but also controls the fuel and water temperature which I don't have?

Middle Fuse controls front and rear side lights which I don't have

Bottom fuse protects the Horn and headlamp flasher which I don't have

I have replaced all the fuses with new ones, I've also tried a new light switch which made no difference

I have been taking out the dashboard and instruments to refurbish the dials with new glass and bezels so something went wrong during this process, I have checked all the wiring visually and can't see any breaks or loose wires also re did all the earth connections I could find.

Car starts and drives fine

Advice and suggestions greatfully received also if any one can recommend a decent auto electrician / Triumph guy in the Rutland/Leicestershire area that would be fantastic.

 

[Colin Lindsay]

Copied and pasted from an online site just now, and for info of contributing members:

The fuse fed by a white cable from the ignition/starter switch protects the following circuits:
Windscreen wiper, Stop lamp, Seat belt warning, Fuel indication, Reverse lamp, Temperature indication, Turn Signal, Heater

The fuse fed by a red/green cable from the master light switch protects the following circuits:
Front parking lamp, Rear marker lamp, Plate illumination lamp, Front marker lamp, Tail lamp, Instrument illumination

The fuse fed by a brown cable from the battery protects the following circuits:
Headlamp flasher, Courtesy light, Hazard warning, Key warning, Horn

When my GT6 top fuse blew repeatedly recently I lost stop lights, horn, wipers, temp and fuel gauges, indicators and heater blower. If your temp and fuel gauges are not working, but you have heater and wipers, these last two may have been connected to a different fuse by a PO, or else wired differently? Do they work when all fuses are removed? Check, just in case, then you'll know if they're wired outside of the fuse box. 

The fact that you're losing circuits on different fuses points more to a connection problem than fuses, especially if the fuses are not blowing. I suspect one or more of your switches has been reconnected incorrectly so that different circuits are being linked - have you perhaps replaced a spade connector on the wrong terminal when you reconnected things?

[MJH2454]

Thanks Colin, I'm pretty sure that I have not connected anything up wrongly as I took photographs of every thing I disconnected in order to make sure that I connected everything back up as it was.

[NonMember]

The fuse box (assuming you still have the original type) is an odd design. The connector at each end of each fuse is made of two separate blades, each of which feeds some of the wiring. It is therefore possible for one of the two to fail to make contact and you lose half of the stuff protected by that fuxe but not the other half.

[MJH2454]

This is where I think I'm going, i.e. a problem with the fuse box, the blades do seem to be a bit loose and flop around a bit.

When I was doing this, I changed the dash lighting bulbs for LED's and after installing them I checked that all was OK, it was, then just before I was going to put the dash panels back in, a few days later, I tried the lights again and this time I thought they flashed on before going pop with an audible noise, investigated the fuses and the middle one had gone, changed all the fuses just in case and this is where I am at the moment.

[poppyman]

If this has only happened since you replaced the led dash bulbs? Have you tried removing them, especially if they are cheap chinese stuff.

Tony. 

[MJH2454]

No the LED's were working at first and I bought them from Classic Car LED's so they should be good

[MJH2454]

Thanks for your comments guys, all sorted now and as one of the comments received suggested, it was a faulty fuse box, nice new modern fuse box fitted hidden inside the glove box and original fuse box left on display