1999 Ford F-150, Python 1500HF Remote Start Won’t Work After Engine Repair

I am hoping someone here could point me in the right direction to getting my remote start working again. I recently took the vehicle to a mechanic to replace all the fuel injectors. After the job, my remote start does nothing--no sound or attempted start. Also, the security system will arm, but it gives an extra chirp after the normal arming chirp, which is supposed to mean that there is some active input in one of the zones when the arming happens. A professional installed this in 1997. I called the local installer, but they aren't very enthusiastic about helping me with an old system, even though they installed it. I assume it is some wire(s) somewhere that got disconnected by the mechanic during the repair. I've already looked at the wire attached to the hood open/closed sensor and that is as it always was (wire connected to a spring near front of hood with other end hard-wired into fuse box), but since I didn't install this unit, I really don't know what else to look for. If images will help, I'm happy to provide. System: Python 1500HF security with remote start Vehicle: 1999 Ford F-150

look for the valet switch under the dash, should be a On/Off switch.. most likely the mechanic flipped it off, while they serviced the truck.

There are a few things that could cause this issue: If the hood pin switch is closed (meaning the hood is open), the remote start will not start the engine. You could use an ohmmeter to see if the wire going to the pin switch reads as if it is connected to ground. The remote start needs a tach signal, if a tach signal is not easily found during the installation a signal can be obtained from one of the fuel injectors. If this is the case in your installation, maybe the wire is now disconnected? The system could have inadvertently been placed in Valet mote as suggested in a previous reply in this thread. You would probably want to verify that the main unit has power, possible blown fuse.

Turn key on. Turn key off. Is the LED on solid? If = yes, it is in valet mode. Turn key on, turn key off. Push the button. LED should go off. No longer in valet mode. See if the RS works now.

Thanks for the replies. I double-checked to see if it was in valet mode. It is not. The LED was not lit solid. I turned key on, then off, then pressed valet button. This put it into valet mode, turning the LED on solid. I then took it back out of valet mode, the way it has been all along. I have since learned some more information to pass along, which will hopefully help you all help me. 1) I decided to try remote starting with the hood open, just as a way to get information and confirm/rule-out things. Guess what... it started with the hood open, but does not start with the hood closed. I mis-stated previously that the hood switch is wired into the fuse box. I was wrong about that. A different, unrelated wire is hooked into the fusebox, I don't know what it is, but apparently it's been there a while. The hood switch wire in fact goes behind a type of black plastic cover/conduit piece on the upper firewall. I can't find where any wire related to the alarm/remote start actually goes through the firewall, but I'm not sure that's an issue. Everything was working fine before the mechanic worked on it. Whatever happened must be accidental while replacing the fuel injectors. So, can anyone think of what would cause the remote start to work with hood open and not with hood closed? That seems like a very specific clue that may help solve the puzzle. 2) I've been reading the documentation that I can get my hands on related to this unit. I found the docs for Python 1500ESP and for the "553A" (instead of mine, which is 553P). Those mention a "tach" wire that can be tied into a non-red wire on a fuel injector. I looked and found a (dunno the correct name) wire connector attachment on the non-red wire of the fuel injector for cylinder #1 (which is the easiest to reach). There is no wire connected to the little add-on wire connector, however. I looked for a wire that seemed loose hanging around somewhere that looks like maybe it belonged there, but I don't see one that stands out to me. I don't know for sure that my unit ever had that wire connected, but why else would there be an add on wire splice connector on that one fuel injector? Would that wire being mistakenly disconnected maybe cause the behavior it's exhibiting (starting with hood open, but not when hood is closed)? 3) The extra chirp that follows the normal arming chirp... I was curious to test if that maybe would resolve with the hood open like the remote starting did, but that extra chirp still sounds regardless of hood position. Is there some way I can figure out what "active input" it's detecting to cause that extra arming chirp, or might that be related to the missing injector "tach" wire? I really appreciate the help being offered.

Problems solved. I investigated some more. I discovered that the hood is not contacting the hood switch at all, therefore not depressing it when closed. There is a worn spot in the paint under the hood where the hood switch has contacted for 20 years, but now it doesn't even touch. I retested the remote start while holding the hood switch down with my finger--it worked. I armed it while holding the hood switch down with my finger--it armed with only one chirp, not the extra one that indicates active input from a zone. So, my conclusion is that there must have been another "bumper" portion that sat over the black plastic post of the hood switch that is visible now, raising the height of the switch to contact the hood. It must have come off, maybe during the mechanic's crawling around the area to replace the injectors. Of course with the hood switch being in the grounded "up" position, the remote start unit thought the hood was up and wouldn't start. Also, the security module thought the hood was up when I armed it, therefore chirping an extra time to indicate that. I can't explain why yesterday it remotely started when the hood was up and the switch wasn't depressed, unless the switch just happened to be in a bind and still a little depressed, but today it rightly did not start when I tried to remotely start it with the hood up. So, I either need to make a little topper for the hood switch post that will increase its height and cause it to be depressed when the hood is closed, or I could just buy a new hood switch. I don't know which I'll do, but I'm usually inclined to repair rather than replace. This still leaves me with curiosity about the wire connector that I found on one of the fuel injectors, shown in photos. I looked but could not see any stray wire that seemed like it was once connected to this connector, but what other possible reason would there be for this connector to be on the yellow wire of this one fuel injector? I'm the only owner of this vehicle since it was new, and I had the security/start module added aftermarket right after purchasing the truck. What are the implications/consequences if there was a "tach" wire connected here at one point in the past, but it is no longer connected?

Nice find! You could unplug the hood pin switch temporarily to allow the remote start to work while you come up with a solution. Just be aware that it would allow the engine to start with the hood open. The wiretap on the fuel injector wire might be there if it didn’t work correctly during the installation and the installer needed to get a tach signal somewhere else. I’ll bet he just left the wiretap there instead of removing it. DEI used to use a violet wire with a white stripe for the tach wire when I was an installer in the 90’s. You could see if there is one going somewhere else in the engine compartment. It is a pretty thin wire, maybe 20 or 22 gauge. The system uses the tach wire to recognize when the engine has started, some systems will also use it to shut the remote start down if the engine starts over revving. Many newer remote start units don’t use a tach wire at all, they monitor the voltage fluctuation while the engine is running.

mj7229, thanks for the helpful information. Your explanation of a possible reason for the empty wiretap sounds plausible. Also, I may look for the violet/white wire at some point if I get curious, but I admit, if things are working properly, I will likely just keep driving and hoping things keep working. Regards.

" I found the docs for Python 1500ESP and for the "553A" (instead of mine, which is 553P)." The suffix letters are for the variations of DEI "Makes". "A" is Avital, "P" is Python, "V" is Viper. The modules, programming and operation are the same. Glad it was simple. I was going to suggest using the onboard diagnostics for the cause of the no-R/S, but I wasn't sure if the DEIs that old have the diagnostics or not. I didn't look it up, but I'm pretty sure the "553" does. 5 flashes is Hood pin.

Thanks davep. I did not know that about the suffix letters, which left me wondering how much I could trust the document labeled 553A, but now that you've cleared that up, I will hold on to it and know that I can rely on it in the future. I don't know if mine has onboard diagnostics or not. When you say 5 flashes, would you be referring to the parking lights or the led inside the truck? When it fails to remotely start because of the hood switch being grounded, I see no parking light flashes, but I'm not sure I've tried it inside the cab. It would be good to know for future problems I may encounter. In case it's helpful for someone else, I thought I'd re-post the link (found on this forum in another thread) for the install/programming document: DEI 553A Install and Programming Instructions