**1991 e150 7seater 302 2wd auto**


Evening all,

I'm new to the forum, so first of all, thank you for having me here.

I have recently acquired a 1991 e150. I love this thing, and it's been running a dream, untill recently.

The problems I have are with the headlights (mainly). They did work fine, but the. All off a suddenly they don't. Not only the headlights, but the rear side lights also don't come on. Along side that (also confirmed to work then suddenly stopped) are the horn and the central locking system.

I have tested quite a few things already, having browsed similar threads, but I'm still stumped.

Any ideas as to what it could be? Why would these seemingly unrelated systems stop at the same time?

Thanks in advance all 🙏

 

Check my signature below, what engine size?
What is rear side light what functionality?
Your dome light working or not?

 

Sorry, in England , rear side lights are the lights that come on with your headlights. Tail lights I guess is a better description.

I don't have a dome light working, but that didn't work previously either.

I've checked the main power wire to the headlight switch (black/orange?) and it's getting voltage, but weirdly it drops to 0 when I press the horn button or the door lock button!? I'm guessing it's developed a short somewhere?

 

I do not believe there is a short involved, but lets look at where power comes to the fuse panel and from there to the light sw.

Evidently when you blow the horn it creates a high demand for power that cannot get thru a poor connection that voltage drops. I would suspect it would be located in the wire that powers the fuse panel. There may be other crazy things happening that you haven't noticed yet lol
.Many times that power comes thru a fusible link from where the link connects to the hot terminal that comes from the battery at the starter relay usually located on the firewall in the engine compartment.It would be a good idea to make sure the connections there are CLEAN and tight and go from there , if necessary.

 

Thanks hankey.

I checked the fuse able link and all seemed good. I'll take some more time to chase the wires and check connections. All fuses seem fine, and the foot switch for the dimmer is all working fine. There is 0.3v to that foot switch when the headlight switch is on, what would that mean? High resistance in the circuit somewhere, like from corroded terminals?

 

Because I have had to replace a few due to corrosion from snow covered shoes during winter times, you could very well be right as far as any headlamp problems.

If in doubt , just replace the switch , pretty easy and not expensive, if I remember correctly 2 screws and 3 wire plug, go for it !

 

1) What engine size, 4.9L or 5.0L or 5.8L?
2) Your van has speed control or not?
3) When your headlight (low beam) is not working, can you try the high beam?

 

1) it's the 302, 5.0L
2) yes it has speed control
3) there is no power to the head lamp at all, either low or high beams. The foot dimmer works perfectly as I've checked resistance through both circuits.

As I've said previously, all this did work perfectly, and then it seems to have just given up the ghost, which makes me think it's less likely to be corrosion?

 

Can you do this ?

Power for headlamps goes from the headlight sw to the dimmer sw and from there to the headlamps.
There is a circuit beaker inside the headlamp sw. Do you show 12 volts at the dimmer sw with headlamps on ? Yes/No ?
If you show power at the dimmer sw,, headlamp sw is OK.
From the dimmer sw power goes to the headlamps, do you have power at the headlamps Yes/No ?
Don't get fooled relying on resistance measurements because if wire has only one strand it will show zero resistance and not be enough to power the headlamps.
If we can get the answers to the above questions, we can move on if necessary. What do you think

 

Ah I see what you mean, okay there is power TO the headlight switch, but not to the dimmer when the headlights SW is in the "on" position.

I would imagine that this points to a bad switch? Is the breaker in the headlight switch resettable?