1996 electronic issues

[TexasRebel]

Issue #1: Wipers that won't shut off.

When I first got the truck last year the wipers were finicky. Sometimes I could make the multifunction switch turn them off, and sometimes not. Then after about 2 weeks, they never would shut off. Truck broke down shortly after so I didn't worry about it. Truck runs again now and I replaced the multifunction switch. Wipers still won't shut off unless I pull the fuse.

Issue #2: No headlights

As stated in the first problem, the truck was down for about a year. Every light worked before, but now the headlights don't work on high or low beam. I don't see a dedicated headlight fuse or relay anywhere but all fuses and relays related to lighting that I can find are good. The headlight ground on the fender well is good. I checked for power at the light sockets and not getting any at all 4. Only thing I can think of is the headlight switch, but I'm not sure how to test it.

Any tips or info regarding both of these issues would be greatly appreciated.

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[alpinecrick]

Are the DRL’s working when you turn the key on? Sounds like they’re not.

Check to see if the headlight switch is getting power.

Are the front turn signals/parking lights working? There are two grounds for the headlights/front parking light harness—one at the end of the harness on the passenger side, the other is on the driver’s side located on the radiator strut, kind’ve hidden below the windshield washer tank.

The wiper module on the firewall is known to crack the circuit board and not work, but maybe the opposite could occur. Try tapping and wiggling the module while the wiper is running while the switch is off. Also, check the connector at the module to see if it’s corroded.

 

[TexasRebel]

Are the DRL’s working when you turn the key on? Sounds like they’re not.

Check to see if the headlight switch is getting power.

The wiper module on the firewall is known to crack the circuit board and not work, but maybe the opposite could occur. Try tapping and wiggling the module while the wiper is running while the switch is off. Also, check the connector at the module to see if it’s corroded.

The drls on these are the bottom housings, right? If so, they work just fine. Only low and highs don't work.

I opened the box on the wiper motor to look at the board. It looks fine for the most part. It's got a couple of small spots on it but the circuits inside still look fine as far as I can tell.

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[HotWheelsBurban]

DRLs on the 400s are lower powered low beams. Not all the trucks had them, mainly the ones built for export or built in or close to Canada and Mexico. My Burbs were built in Silao, Mexico and both had daytime running lights. There's a relay for them under the dashboard, but you about have to stand on your head to get to it. Replaced it on the first Burb, redrilled the mounting hole to make it easier to get to. Haven't messed with it on the current Burb yet. On this one, they'll be on for a few months, then not be on for another few months, then they start working again. All other light modes work exactly as supposed to, so it's probably the relay acting up. The other Burb did the same thing before the relay was replaced. Have other dash work to do on it, figured best to do all at once. Just waiting for cooler weather.
Sounds like you have a wiring problem to me,just going to have to look at the wiring harness, and check out the connections and grounds.

 

[TexasRebel]

DRLs on the 400s are lower powered low beams. Not all the trucks had them, mainly the ones built for export or built in or close to Canada and Mexico. My Burbs were built in Silao, Mexico and both had daytime running lights. There's a relay for them under the dashboard, but you about have to stand on your head to get to it. Replaced it on the first Burb, redrilled the mounting hole to make it easier to get to. Haven't messed with it on the current Burb yet. On this one, they'll be on for a few months, then not be on for another few months, then they start working again. All other light modes work exactly as supposed to, so it's probably the relay acting up. The other Burb did the same thing before the relay was replaced. Have other dash work to do on it, figured best to do all at once. Just waiting for cooler weather.

In the block above the pedals? I saw it when I was replacing the multifunction switch. I pulled it and it looked fine and didn't smell burnt. If that can cause my lights to not work, I'll give that a shot before I replace the switch since it's only like 10 bucks. The truck was built in Fort Wayne, so I'd say it was close enough to Canada to get them.

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[HotWheelsBurban]

IIRC it's more toward the center of the dashboard, but that was a few years ago when I did that job....Do you have the shop manual? It should have more information.

 

[TexasRebel]

IIRC it's more toward the center of the dashboard, but that was a few years ago when I did that job....Do you have the shop manual? It should have more information.

I don't have a shop manual for this truck. Just looked it up, it's where I thought it was above the pedals. Next time I go out to the truck, I'll swap a new relay in. I just find it weird that it stopped working while the truck wasn't running.

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[HotWheelsBurban]

OK cool, I thought it was further over. Maybe the 98-99 are different. But I do remember it being a pita to get to. But I don't particularly enjoy under dashboard work.

 

[TexasRebel]

OK cool, I thought it was further over. Maybe the 98-99 are different. But I do remember it being a pita to get to. But I don't particularly enjoy under dashboard work.

I hate under dash work too. Luckily I'm not too big of a guy to fit down there. It's not comfortable, but I can do it. Dash is probably gonna come out of the truck sometime next year to get painted while I clean up old wiring and replace the soft/foam parts in the ac system.

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[HotWheelsBurban]

I hate under dash work too. Luckily I'm not too big of a guy to fit down there. It's not comfortable, but I can do it. Dash is probably gonna come out of the truck sometime next year to get painted while I clean up old wiring and replace the soft/foam parts in the ac system.

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Yes my best case scenario on my Burb is to be able to replace the whole dashboard, since it's cracked like they all do....But that depends on being able to find a good dash and having the truck down and apart long enough for the job. Blower motor doesn't work, and I think it's probably the switch in the dash stack. Stereo also works when it feels like it. So I'm going to replace the switch and the radio/CD deck, with the ones from my other Burb ( which worked great when the truck was wrecked). At that time I'll look at the blower motor and resistor and the wiring harness. Haven't had the Burb parked for long enough till the last 2 weeks to mess with it.