lighting problem

[bahbzilla]

I had to pull my dashboard and replace a badly cracked fuse panel (1980 DHC - 12 fuse panel)to fix some goofy intermittent headlight problems. That is done and the headlights are fine, but I am left with 2 new problems.

1) Right side tail light and front amber marker light do not work. Headlights, hazards, turn signals, brake lights and left side running lights all work fine.

2) Instrument panel lights don't work. Turn signal/Hazard indicators and warning lights and gauges all work fine, just no instruments lights. I tried bypassing the dimmer to see if it was shot, but no luck.

Both of these things worked fine before I pulled the dash. I am sure that there are MANY possible reasons for both of these problems. Does anybody have any experiences with either of these?

Thanks

Bob
1980 TR7 DHC

[FI Spyder]

I've got the same thing (no dash lights, no switch lights, no cigarette light) after I pulled the consul to check radio speaker connections. These all come from the dimmer (problem may come before it). I have lights on heater levers. I checked continuity on dimmer and some wires, OK. I am about to go back in when I get a chance to check some voltages. I also await suggestions and will post any findings I come up with.

TR7 Spider - 1978 Spitfire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[Ianftr8]

I have had similar problems over the years, with one front sidelight not working the oposing rear light/cruising lamp not working and the dash lights & cigarette lighter lamp.
I have pulled eveything apart and cleaned - remade joints and earths - the problem still occours from time to time but my fix is always found at the master light switch - give it a wibble (note technical term) and all is fine.

Hope this helps a little.

Cheers
Ian

Ian Freeman
1979 TR8 DHC California car that never crossed the pond, started life as KDU 315V.
1962 Triumph Courier

[bahbzilla]

While I had the dash out, I replaced the headlamp switch and the cigarette lighter. When I put in the new cigarette lighter, I noticed that the old light bulb was burned out, and the new one stayed on ALL the time. I disconnected the wire from that light because I didn't think that was a very good idea. It later occurred to me that this was a red/white wire, the same as the right side lights I am having trouble with. I reconnected the cigarette lighter lamp hoping for a miracle, but alas, no change.

Bob
1980 TR7 DHC

[bahbzilla]

I do however, have a 2 contact female connector behind the radio with 2 red/white wires and one black wire that is not connected to anything. I didn't think it was connected to anything when I pulled the dash, and I can't find a male connector anywhere for it to plug into...

Bob
1980 TR7 DHC

[neil williamson]

When I purchased a DHC it had various light maladies.It all seemed to be connected to the main light switch.So I bought a new one and everything was perfect!As the newest 7 is 30 years old it may be advisable to consider renewing this item.About £15 but saves a whole lot of problems.Dont forget the phrase-LUCAS THE PRINCE OF DARKNESS! How true is that!

[nervousnewowner]

I was clearing up the wiring on my dhc and decided as i would never use a rear screen demist button i would take out the wiring to make some more room, lost all dash lights that way, white wire in the plug is a connection for dash lights too for some reason, put the wires back and everything worked......


the project at birth, watch it evolve...I hope...

[FI Spyder]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by bahbzilla</i>

I do however, have a 2 contact female connector behind the radio with 2 red/white wires and one black wire that is not connected to anything. I didn't think it was connected to anything when I pulled the dash, and I can't find a male connector anywhere for it to plug into...
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

The two red/white wire/one female contact fits onto one of the male contacts on the dimmer (there are four, only two opposing are used). The black wires are ground. The lights for the heater controls are grounded with black wires. The main light switch is not my problem as my heater lights work and are on this circuit. We're going to get a week of blue sky days so will be able to back the car out, pull the seats and consul and get at this problem. This was another self induced problem as it happened when I pulled the consul to check speaker wires (again not the cars problem as the bias on the radio was turned to rears of which there is none. I had mistaken which is the front rear bias knob.)

Interestingly of the handful of problems I've had with this car, not one was due to design or manufacture of the car but do to PO's or CO's (current owner) mistakes, stupid or otherwise.[:p]

OK, thought of one, broken headlight hi/low switch.


TR7 Spider - 1978 Spitfire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[Laird Scooby]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Interestingly of the handful of problems I've had with this car, not one was due to design or manufacture of the car but do to PO's or CO's (current owner) mistakes, stupid or otherwise.[:p]



TR7 Spider - 1978 Spitfire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

That's what i use a very technical term for - Finger Trouble!!! Keep the meddling fingers out and it keeps working! Lol!! Joking aside though, sometimes it can be very useful to go poking around and create faults like these as not only does it teach you a few things about your car but also shows areas that need attention either now or imminently.

Does the TR have those awful bullet connectors that Lucas were fond of using, especially to join one wire into another? Usually a black/dark grey rubber sleeve over a female bullet receptacle that is often designed for 4 bullets to go into is how Lucas joined cables in the system i'm thinking of. For example a green wire might need to have a green/black wire joined to it. So they would cut the green wire, fit bullet connectors to the ends then use one of these horrible joiners. The green/black wire would then have a bullet fitted to it's end and this would be pushed into the joiner. I can't begin to count the number of faults i've had where the wires have partially come out of the joiner so they look connected but have in fact become disconnected inside! Also they are prone to corrosion inside and becoming loose over time. This is cured with emery cloth on the bullet and a pair of pliers to tighten the receptacle. Getting the bullets into the receptacle is a fiddly and often painful task. Lucas used to produce a tool to do it which looked very like a pair of pliers with strange ends that located on the "back" end of the bullets and pushed them together inside the receptacle.

The point to all this waffle is that you may have disturbed one or more of these in your dashboard explorations although to be honest it sounds like an earthing problem. Try getting a long length of wire and jump from battery +ve to the non-working lamp. If it lights, there is a wiring problem further back. If it doesn't then there is either a blown bulb or an earth problem. You can then follow the circuit back and find the fault by jumping to the battery in this manner.

Hope this helps!

Cheers,
Dave

[busheytrader]

Hi,

Wedges don't have the "bullet" connectors as such, (the Mini Cooper I'm restoring has dozens of the little b****s) but there are a plethora of connectors directly behind the main switches, around the steering column, underneath the false speaker panel at the top of the dash and around the glovebox where the relays and fuses live.

Any one of these connections can have wiggled out of their plastic block. The headlight switch is particularly suspect to green gunge which needs regular cleaning.

adam



TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 14" 5 Spokes or Maestro Turbo 15" Alloys, Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991

[Laird Scooby]

So it's the usual Lucas "explosion in a spaghetti factory" wiring loom then? Maybe i was thinking of the Stag or another BL 1970s offering that i've worked on at some point with the bullet connector things.

The best way of finding and fixing any electrical problem is to work methodically. Once you think you've found the problem by bypassing the offending component, put the suspect component back in circuit and see if the fault comes back. Once you are able to replicate the fault in this way 100% of the time, you know you've got the fault.

Cheers,
Dave

[FI Spyder]

Spitfires have the bullet connectors. Not to bad to clean them and then put dielectric grease on them to keep them from corroding but not as good as the sealed connectors we see on modern cars. Just as Mr. Lucas said "A gentleman does not drive after dark." I'm sure he also said "A gentleman always has his man servant/mechanic available to clean his motor car electrical contacts." [:D]


TR7 Spider - 1978 Spitfire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[FI Spyder]

I found my no dash lights - no switch lights problem. quite easy to spot. Took the cowl off. I had heater control lights so I new I had 12v at the dimmer switch where the two red/white wires come off. One of them goes to the heater control lights. The connector was soldered on. the second wire goes to an unused connector that supplies power and ground to whatever accessory you want to plug in. I use it to plug the blue wire in for the radio illumination. The red/white wire then goes to the heater light (wasn't working) then to dash/switches lights. I took off thefplastic guard and saw one of the two wires was not connected well so I soldered them. It was the only connector not soldered. Nice going Rover guys (either the factory guys or the JRT guys where the PO used to get it serviced.) I've got lights now. Next the BMW windblocker. I've figured a neat way to mount it with out drilling into the body of the car (if it works) but that's another post.




TR7 Spider - 1978 Spitfire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[bahbzilla]

Problem solved. All of the non-working lights run off of the same fuse. I had already replaced that fuse with no success, but when I jiggled it around with the lights on, they came to life. Apparently it was a bad connection between the fuse and the tabs in the panel. Straightened out the tabs, and I am back in business. I also learned that the instrument panel lights are purposely fused with the tail-lights as a warning to the driver to check the tail-lights...

Bob
1980 TR7 DHC

[bahbzilla]

I also learned that the unused pigtail I asked about that is pictured in Spyder's post is used for console lighting in automatic transmission cars.

Bob
1980 TR7 DHC