Damn them electrical Gremlins :X

I hate to bring up another electrical gremlin story but I've got another. I finished installing the newer tach and then went to start the car again to be sure all the electrical componets function and I've now lost my high beams and rt tail/brake light. WTF?!?! The regular lights work just fine and the lf tail/brake lights work. I've a colored wire chart that looks completely different from the chart in my Haynes manual so I've no idea which to use. I'm thinking that somwhere along the line I disconnected a wire somehow since everything except the tach worked. any sugessstions on where to start since I'm confused on which chart to even use? My VIN # is GAN5UC111762G is some has the correct chart that can sne dme in a PM I will be in debt forever!!!! Is there a way to use the voltage meter to see if there is current/contin. in the wires or just try the red to power and black to bare metal trick?

Jason

Can anyone confirm which chart in the Haynes book I can use for the above VIN #? On page 205 chapter 10 this is what u read..."USA GAN5-105591 onwards to end of 1977 production". So we actually use the same diagraph for 1972 1275s through 1977 1500s??? Does not seem right to me. Also, this particular chart is super simplistic as compare to earlier models which again confuses me. Did they remove half of the wires for these years? Plus, it shows there are 2 of all these: right and left hand stop/tail lights as well as rh/lh headlights? How can we have 2 of each light on each side? I just purchased a really nice colored chart for my 74 and it's extremely more complex than the chart Haynes is saying to use. Can anyone shed any light, no pun intended, on what gives? Are the Haynes charts all wrong?

IMHO Haynes manuals are similar to Moss parts - you often have to "file to fit", as Frank Clarici used to say. The Haynes manuals were written to cover all models and in my experience they don't do a very good job. You have to be able to read between the lines and decipher the differences between models. In another lifetime I was a tech writer for Kawasaki and Mazda and I wouldn't put my name on a Haynes manual. The Bentley manuals are much better.

Why not use the new color wiring diagram you bought?

Rick

Well for starters it does even show a tach anywhere on the chart...? Also, it shows a ton of gray boxes which zero indications in what they are. It's also for my 74 but I figured that would be alright for basic routine checks. I got it from Prospero's on eBay. Just sent a message asking why there's no tach on it.

Jason

Just did some checking and apparently the wiring diagram for 1275 Midgets from S/N 105501 and up is the same as for the 1500's through 1977. Who'd a thunk it? :) I have a pdf file of the wiring diagram for the '78 Midget if that would help.

Rick

JJ I had a long chat with prosperos before I ordered my diagram for my wifes 1970. I have seen many "general " diagrams that were confusing. My Prosperos was serial number specific and spot on. Are you sure you ordered the correct thing? To my knowlwdge there is not a midget w/o a tach. Sounds to me like you disturbed some wires under the dash while you were changing tachs. I'd start with the bundle coming from your highbean sw. I am at work so I have no colors to give you but if you go out front tothe headlights you'l find 3 wires off the headlight. One is ground (blk) the other 2 represent the hi and lo beam colors. find them in the bundle at the dash (steering column) and make sure they are plugged in correctly. You must be getting power to the dip switch since the one beam works. As far as the tails I'd start with grounds. They may have no relation to the headlight issue or tach switch

Check thar colored diagram. I bet you received something for another vehicle

Good luck Toby

That's the fourth time I've heard Haynes being somewhat questionable. Time to order a Bentley guide I guess. Doug at Prosperos answered me and he was right that what is marked "speedo" must be the tach based on the wires but now I don't see the real speedometer LOL. Thanks for the tip about just tracing the wires back from the front...I was beginning to think the same since they worked before putting the tach and steering cowl on.

Hey jason

Before you get involved on this

The biggest issue with the "Prince of darkness" yes thats what lucas wiring is really called

Are the electrical bullets and grounds...esp in the spring...and if your area is like missouri...then its pretty much spring type weather

What happens is there is high humidity cooler temps hitting warmer temps in the same day causing condenstation...and grounds / bullets hate condenstation and will work as well as great grandmas internal plumbing after a trip to taco bell

Ither let it set for a few days to self cure or undo the grounds, clean, and relubricate with electrical grease as well as your bullets...id lay even money this is your issue,,,its so common and notourious....

sorta like MIA singing at a madonna concert....hahaha

Yeah i went there

Prop

Thanks Rick that makes sense as there is a big circle with only a light in it marked "panel light" so I guess I'll use the color chart and go from there.

Does that have a 4 fuse box? I dont have diagrams in front of me, but with the 79 i was workin on the taillights and headlights are split wierd left to right and the headlights were tied in in the box....there are 2 fuses for the lights if i remember correctly.

I would prolly start with removing and cleaning, very throughly the fuse box. And checking with a meter all the ins and outs...i has an issue where id get power on one pin and not the other for one fuse. As the box has multiple pins for each fuse....This is where it can get wierd...like I said, check each pin going in and out with a meter, not a test light...a meter to be sure what is going in is whats coming out

Well here's where I'm at, the right brake light and turn signal both work but not the right tail lamp. The bulb is working as I switch with the other car. Regarding the the high beams, when I pull the directional switch back nothing happens and when I push it forward the main beams shut off like they should but still no high beams. Next step is to again dismantle the steering column to remove the cowl and examine the directional switch itself. Is it possible the switch maybe the culprit for both issues?

The headlamp high beams are controlled by the directional lever activated switch in the steering column. But the right tail light is controlled only by the light switch. It's wired in parallel with the left tail light so the problem has to be in the wiring at the rear of the car. Check the ground at the bulb socket.

Rick