• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

A new short in fuse #3

Share this page

F

fadler1

Member
Offline
A new phantom Lucas ghost. The car was fine for weeks but when I turned on the turn signal, the tach would bounce down and recover. Now fuse #3 in the 4 fuse circuit blows instantly upon replacement. Where to start. That darn fuse controls a whole lot of stuff. One guy said replace the fuse box since corrosion and cracking does it. Anybody had that happen? Replace the turn signal assembly? By the way, the turn signal never turns off either. I assume it is alignment of the "bump" on the column.
 
Always put in what year car you have as wiring diagrams are specific and different. The correct one for my car is not even the nice color one for 67-70 I downloaded off the internet but is #8 in the Bentley manual ..."68-69 for certain jurisdictions" and I had to figure out which one it was from looking at connections in section of system and matching it up to the diagram. Potentially a short somewhere....bad switch, wires abraded (I had white wire to fuel pump lose the fabric insulation and abrade it and two other wires near the clutch slave cylinder from rubbing against metal clamps holding the wires..shorted it out and melted my wiring harness). So....don't let it overwhelm you. Get the right diagram and blow it up larger so you can learn that circuit then trace each part of it and see if you can find what is dodgey. Switches should not show continuity (get continuity tester) when off and should when on. You can use multi-meter to test for wires that are grounded when they shouldn't be and also to test for current flowing in wire when it should and shouldn't. Test each section of that circuit and eliminate it to find the problem. I am not naturally good at this stuff either but am learning as I need to. Look for obvious stuff first like wires hanging loose, broken or abraded.
 
oh.....also get long wires 8-10 feet and make test leads by soldering alligator clips on the end...that way you can get on both ends of a circuit to test it out.
 
Back
Top