1995 Ford e150 van dash lights & tail lights won't stay on at same time-tried replacing headlight switch twice

Thats weird, the instrument illumination fuse has historically been a 5 amper that is separate and powered up when the switch was pulled out. They increased with turning of the rheostat. The taillights were supplied power and the lights worked in two switch positions. since newer vehicles incorporate a multifunction switch, and it receives alot of useage and wear, and it gets its mains from the same sources, it stands to reason, that you can do the system prechecks first, then refer to their depictions in the EVTM, or a schematic you search using the terms provided. I have disassembled multifunction switches in the last 10 years many times and found water entry, contacts needing cleaned, and coffee, believe it or ? But inspections of relays, substitution, and known good parts to swap in have always been the technicians friend. I have no books for yours, but suspect looking into your circuit protections, relays, connectors, and that MF-switch will solve it.

Your main light switch for the 95, does it have a dimmer wheel? be sure its turned up and check every fuse for power on both sides when operating. use a test light, volt meter, or a cont. tester. A "wiggle test" is allright by me too. then there's the tap test, the thump test, and the Ford wrench we used to use for ambulance.

Connector inspection can be a time saver. If you know the items in the circuit and where they share, you can remove connectors and look at them for signs of heat. The lightswitch and the MF switch have been historically underwired for the resistance that becomes present later in their years of service. After 20 years of hard tires and unpaved roads especially, plus water entry and buildup and wear in metals inside switches. The resistance can become exponential and the resulting heat can sizzle the grease protecting the connector pin to switch prong mating. There are repair connectors, with leads, with beefy leads, or even factory bulletins about it for some models. Motorcraft supplies this need and there are some, just get you by type suppliers in the aftermarket. You would see discoloration and distortion in the connector end view. Ford parts counter can be of help in determining part numbers, and Ford service can be of help with bulletins, or campaigns if it applies. I would not be afraid to call and ask, they have information systems simplifying and people with concentrated experience.

I read some discussions that, it should be noted are not properly marked for make model and year. They were Ford related, truck related, and about dash, parking and taillights. They were reminding that add ons, towing and other additions to the tan/white wire were adding to resistance issues, connector overheat, and sometimes wire break or burn through? What Ilearned is that the wire can go on you between the fusebox and the switch. The fuse may supply, but it could be lost as an open. you would chech power with your test light at the light switch connector where I thought you would find your melt, distortion, or discoloration. The brown wire, they were saying feeds many lights from there. The idea about the tan wire being kinda weenie for adding to was you could run another wire from its source thats a little better gauge. Needing the connector pins would still be a parts issue if its connection suffered at the switches. See if thats not the issue. The add ons for lights like upgrades and towing may be fused elsewhere besides the vehicles fuse panel, see if you have a ford trailer harness and the package. add ons of another source are individual to that vehicle.

Lets sum this all up to help plan a diagnosis. voltage drops at a connection, caused by resistance. power available diminishes as voltage drops. heat builds as resistance builds till the inadequate wire (added to) melts burns or severs but does not short to ground. How bad is it? depends upon the length of time, times it was hot, and for how long, vibration and other resistances from switches connectors or problems with add ons. This is likely, you can report what happenned to yours because there is no discussion I find thru google specific to your van info, just similar. tell me if this helps please or if we have failed to discuss the cause, the circuit, switch, or connector, even a light relay or some other component, distribution circuit from the main box, or harness area specific perhaps, you could have. Then select anything you found helpful for the website, please.

After a proofread, i thought you may not know what an EVTM is, its an Electrical and Vacuum Trouble shooting Manual, you can get one, look at one at a Ford dealer, or read one in a library reference section sometimes. it is full of everything you would want, schematics, drawings in bold, color, and specific attempts at locations with drawings, they come from Helm publications. .............................................Theres also discussion on google about lightswitch issues for the rheostat, It's the same design as most and they are not necessarily talking about yours unless you overheat the dash light circuit. Some add ons we did not mention are radio illumination, and The thing about the switch tech upgrade hinges on 95 to 96 model year. This is why having a correct schematic saves time, aggravation, and misdiagnosis. The threads that come up are not necessarily the exact same, they are bro-II, aerostar, then full size bronco, then F-series, they do not necessarily mention E-series and any difference, nor Cut-away chassis. There are two fuses in play normally, and they get theirs normally from a main power distribution. If you have an issue that has an odd quirk, like two circuits that seem to interact or one seems to cause loss of the other ? You can have oddities like crossed bulb filaments, instrument cluster issues, connection issues, Wiring that has been changed by an aftermarket installer. Your fastest most accurate technician works at the Ford garage. he has the info others lack and uses Ford part numbers and correct updates. Hope you are finding what has been done or lost or crossed, feel free to update and tell your findings step by step if you need to.