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MG MGB GT V8 Factory Originals Technical - More electrical gremlins
|Having got my 75 GT with Rover V8 running recently after fixing ignition problems with help from this board, I now find that i have no indicators (Hazards work) windscreen wipers,washers or heater fan,or cooling fans although these are now wired through a relay, also the V8 tacho I have just fitted does not work and yes i did not forget to refit the earth. I have checked the fuses (new fuse box) and there dosn't seem to be any power with ignition on to the connections on the second from bottom green cables, which i believe feed all of the above. Any suggestions?|
|The indicators and tacho come off the last but one fuze - it tends to blow because of the current taken by the fans - have a look first at the fuze itself - you can't always see if this kind has blown - next have another look at your new arrangement for the fans - is it still taking current from the same fuze ? |
Thanks for responding, I will replace the fuse as suggested in case its as simple as that. Presumably with ignition on one side of the second from bottom fuse should be live, is that the white or green side. please forgive my stupidity in matters electrical but when I look at a wiring diagram it makes as much sense as a plate of spaghetti!
Notm sure where the electrician wired the new relay to, there is a new fuse block installed with 4 extra fuses to cover previosly unprotected circuits, I have also checked these and they all appear ok.
Yes - I suspect the fuze - (just swap the two lowest) the (my) factory V8 has the forward side of the fuze live with the ignition switch.
It's a good idea to put the fans onto another fuze - the power needs to come more or less straight from the battery via the block under the r/h chassis rail.
Not knowing how your spaghetti is (re)arranged I am afraid I can't help but as with all mods - I would get it carefully documented.
PS When I lose the tacho, I know I have also lost the fans and there is very little time before she boils - I suggest you put a tell-tale light on the dash to give you some warning too.
No wasn't the fuse, no power on the white wire on the front side of the fuse box. Did a bit of wire tracing and found a white wire with a bullet connector down near the brake pipe distribution union which isn't plugged into anything, not certain if this is the wire that ends up at the fuse box because it goes into the wrapped loom. I have a new voltmeter and circuit tester so came home to read the instruction book, Lesson 1. always keep the instructions with the equipment! I will do a circuit test and see if this is the correct wire and find a feed from the ignition for it. I think what has happened is that when I got an electrician to wire in a new feed to the coil to try and solve that problem, he cut out the old ballast feed connection and left this without anywhere to go. Lesson 2. don't use cheap car electricians.
Anyway with the help of Dan Masters revised wiring diagram, even I can now understand how the wiring works and hopefully sort out my own problems in the future.
This is a great BBS and it has been extremely helpful on a number of issues. I dont contribute very often as I feel there are many others who are better qualified, but do jump in on the occasional point where I feel I can offer informed advice. I do check in on a daily basis and would like to thank all those who contribute.
Thanks for the feedback - I can echo your sentiments
|Success!! The white wire with the bullet connector with nowhere to go was the feed to the fuse box, bought a packet of bullet connectors and new bullets from Halfords just across the road from where the car is garaged, wired them in and Voila I have wipers, washers heater fan, Tacho and fuel guage all working.|
Also fixed the LH mainbeam that wasn't working, again bad bullet connector and was extremely pleased with myself. Thought i would do a last pre MOT check only to find that the reversing lights are not working,bulbs ok so could be the switch I think this will be a little difficult for me to get at so will get my mechanic to sort it when he does the pre MOT service, so should be back on the road in the next week or so. Dan Masters wiring diagram makes it so simple, couldn't have done it if he hadn't posted them on the board. I think it would be prudent to replace all the old bullet connectors which i will do in the near future, I have seen mentioned on the board something I believe is called dialectic grease which protects the connections and maintains a good electrical path, anyone know where this can be purchased?
|It's spelt V-A-S-E-L-I-N-E and you can get it anywhere except electrical retailers.|
Seriously 'tho - it's a good idea to work round all the connectors every two or three years - re-wiring probably should also feature somewhere on the maintenance schedule for most of these cars.
Thanks, I think I have a jar of that in the house somewhere, not in the bedroom!
I think the product I read about was mentioned by one of our American friends and thought it was some Hi- Tech product but if Vaseline will do the job, thats fine.
|Dielectric grease is fairly expensive. I've used it when replacing plug wires but that is about it. They sell tiny tubes of the stuff in the local R&S Strauss, but there has got to be a better, cheaper source for the stuff.|
I've used vasoline on battery terminals for years with great results.
This thread was discussed between 15/05/2005 and 03/06/2005
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