oppie2005

There is this 1994 f150 supercab xlt 4x4 that im looking to buy. Its a really good looking truck, and the price is REALLY good....however, it might have a couple of issues.

When the truck is idling, it runs fine and sounds good but, if you turn the headlights on, it kills the engine. If you turn the headlights back off, then you can start it back up.

When you turn on the left turn signal, it works flawlessly. If you turn on the right turn signal, the hazards come on, and the truck starts running rough and the rough running is in sync with the flashing lights.

and, one last problem. There is a slight scent of coolant in the air when the truck is running, but nothing shows to be leaking. and the top rubber hose on the radiator doesnt feel like there is any pressure.

First question, has anyone had any of these issues, or know of possible corrective actions?

Second question, Would these issues be a deal breaker if the rest of the truck was in pretty good condition?

any/all help/advice is greatly appreciated.

oppie2005

bump

Fast Hampster

1 - all electrical issues seem to be about bad grounding to me. Probably right headlight assembly is not grounded right or not grounded at all. Also it might be a general body grounding, it's hard to say from over here.

2 - coolant scent seems a bit more important issue to me. At first, coolant level is to be checked - block heads don't like to run dry. Possible scent sources are: water pump leak, heater core leak, head gasket leak. Any of these can be fixed, but it'll take some $ to do it.

oppie2005

Thanks Hampster.

planehunter

IMO it depends on the condition, cost and how good you are at solving these type of problems. If it was me, I would pass unless I wanted a project truck to work on.

oppie2005

Thanks planehunter.

Could one of you tell me where the main ground points would be found at?

Also, do either of you know where i could find wiring diagrams?

Thanks.

Mass0wnage

Strikes me odd to see someone else finding this particular issue. I just dropped a 5.8L in my 93. At first start it ran awesome. Then I went to head to the gas station one night after replacing my rear fuel tank. Turned the headlights on and the truck died. Wasn't a sputter or anything. Just died as if the ignition was cut off. With the lights on, the motor would turn over, but would not fire. Turn lights off it started right away.

Seeing as it didn't die when I turned the parking lights on, I had to troubleshoot. I unplugged both headlights. Turned the truck on. Pulled the headlight switch. Truck didn't die. Plugged the headlights in 1 by 1, Truck didn't die. Hasn't done it since.


The coolant smell, could very well be a small leak anywhere in the system. Had this problem several months ago. I searched everywhere and couldn't find the leak. Every other day I was having to put coolant in it, but could never spot the leak. No puddles on the ground anywhere. Tried parking on cardboard. Never saw anything. Stopped to get gas one day, truck started running hot. One of the hoses going to the thermostat housing had a 1/4" slit in it. Was on the bottom of the hose, so you couldn't see it without taking it off. Try listening to it. If, after running for 10 minutes or so, and gets up to normal operating temperature, and you hear water boiling. Then you'd need to replace that thermostat pretty quickly.

oppie2005

Thanks Mass0wnage.

I read somewhere on a bronco forum that they had the same problem with the headlights and they replaced the switch and that fixed it. Im going to pick up the truck today, and will probably fiddle with it for a little bit before i have to sleep for my night shift. The previous owner said that it all started when he replaced a tail light, so i will probably disconnect the tail light and start my troubleshooting there.

For the coolant smell, i couldnt find a leak anywhere, no dripping or nothing. No overheating no steam coming out of the vents, no liquids in the floor boards. so im really not sure what the deal is with it, but something im gonna have to watch for. I didnt hear anything like water boiling, but i wasnt listening for it either. Ill have to listen for it. What other signs are there for the thermostat going bad?

oppie2005

do any of you happen to have a 2 prong plug at the rear drivers side of the bed that comes out near the top that is ran through the tailight cavity?

Chris Rhyne

I have it I believe it supplied either brake light on a camper shell or a dome light in the camper